kernel development returning to after 10 years

[Ruben Safir]

 Hello

 I'm taking a class on operating systems and it includes, happily,
 many Linux examples, outlining OS internal structures and algorithms.
 I wanted to delve into the Scheduler, particularly the CFS that has
 been implemented and to try running and testing things such as what
 is outlined here


 
http://www.embedded.com/design/operating-systems/4371651/Comparing-the-real-time-scheduling-policies-of-the-Linux-kernel-and-an-RTOS-



 In order to do this, I need to compile and code the Kernel and
 Kernel modules.  I've done this many many time in years gone
 by, but the current kernel has seemed to have grown even more
 than I anticipated.  For those who work on the kernel and drivers
 everyday, what would you recommend as a best approach to tinker
 with the scheduler or even tinker with struct.h entries.

 I set up a VM with oracles virtualbox, and even that was new to
 me.  I used to keep a usb drive to development and rebooting
 when I last attempted this.

 Ruben

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Get Back Into Kernel Work

[Ruben Safir]

On 03/15/2015 08:55 AM, Levente Kurusa wrote:
> Hello, Nick.
> 
> On Sun, Mar 15, 2015 at 12:34:33AM -0400, nick wrote:
>> Greetings All,
>> After my terrible results before and getting banned from the list due to 
>> these results,
>> I am wondering if there is any work in the USB or Networking Subsystem I can 
>> start with.
>> Further more recently I read Essential Kernel Drivers so I have some idea of 
>> how
>> to write drivers now and want to get my feet wet. In addition if I am still 
>> not 
>> trusted yet,that's OK too. :)
> 
> Well, ideally what you should do is look through drivers/staging and
> select a driver that looks interesting to you and has some work that
> needs to be done, then you get a hardware for that particular driver.
> Please do not skip the step where you actually get the hardware, given
> your previous behavior I think we all can agree that is likely to happen
> though... Surprise us! ;-) If you have the hardware, you can run tests
> on it, stress test it or boot into Windows and see what the Windows
> driver does that the current Linux driver does not do.
> 
> Hopefully the hardware itself won't cost too much and is easily obtainable
> using Amazon or Ebay.
> 
> Hope it helps,
> Levente
> 
> 
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 


Did this get hijacked?

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Get Back Into Kernel Work

[Ruben Safir]

On Sun, Mar 15, 2015 at 05:16:27PM +0100, Levente Kurusa wrote:
> On Sun, Mar 15, 2015 at 12:01:27PM -0400, Nicholas Krause wrote:
> > >> [...]
> > I was interested in Socs in staging as I believe there are a few
> > would someone like to point me to one that I can get hardware for.
> 
> Please read my message again. It should be YOU who does the research
> about the work that YOU want to do, not us...


I didn't write this.  Are you intentionally trolling this?

The initial message under this subject had nothing to do with this.
BTW - the atitiude is piss poor for what is SUPPOSED to be newbies area.
Try taking some trips from Ernie and Fewer from Bert.

Ruben


PS - no need to CC me when I'm reading the list.

> 
> Thanks,
> Levente



-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com 

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive 
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com 

Being so tracked is for FARM ANIMALS and and extermination camps, 
but incompatible with living as a free human being. -RI Safir 2013


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Start it again .. Returning the Kernel Writing

[Ruben Safir]

Hello

 I'm taking a class on operating systems and it includes, happily,
 many Linux examples, outlining OS internal structures and algorithms.
 I wanted to delve into the Scheduler, particularly the CFS that has
 been implemented and to try running and testing things such as what
 is outlined here


 
http://www.embedded.com/design/operating-systems/4371651/Comparing-the-real-time-scheduling-policies-of-the-Linux-kernel-and-an-RTOS-



 In order to do this, I need to compile and code the Kernel and
 Kernel modules.  I've done this many many time in years gone
 by, but the current kernel has seemed to have grown even more
 than I anticipated.  For those who work on the kernel and drivers
 everyday, what would you recommend as a best approach to tinker
 with the scheduler or even tinker with struct.h entries.

 I set up a VM with oracles virtualbox, and even that was new to
 me.  I used to keep a usb drive to development and rebooting
 when I last attempted this.

 Ruben

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Get Back Into Kernel Work

[Ruben Safir]

On Sun, Mar 15, 2015 at 04:39:31PM +, Hugo Mills wrote:
> On Sun, Mar 15, 2015 at 12:24:12PM -0400, Ruben Safir wrote:
> > On Sun, Mar 15, 2015 at 05:16:27PM +0100, Levente Kurusa wrote:
> > > On Sun, Mar 15, 2015 at 12:01:27PM -0400, Nicholas Krause wrote:
> > > > >> [...]
> > > > I was interested in Socs in staging as I believe there are a few
> > > > would someone like to point me to one that I can get hardware for.

Your 100% correct.  I apologize

Ruben


> > > 
> > > Please read my message again. It should be YOU who does the research
> > > about the work that YOU want to do, not us...
> > 
> > 
> > I didn't write this.  Are you intentionally trolling this?
> 
>Nobody's claiming you did. This is a different thread to yours,
> with a different subject line. Note that none of the quoted messages
> above had your name as attribution.
> 
> > The initial message under this subject had nothing to do with this.
> > BTW - the atitiude is piss poor for what is SUPPOSED to be newbies area.
> > Try taking some trips from Ernie and Fewer from Bert.
> 
>This particular newbie (nick) has a reasonably long and ignoble
> history in the kernel development area. He used up quite a lot of the
> available polite late last summer, and isn't at the moment giving any
> indications that he's made any improvements.
> 
> > PS - no need to CC me when I'm reading the list.
> 
>It's the default position on these mailing lists. You're generally
> not going to have anyone remember that you don't want to be CC'd. A
> message in your .sig to that effect might help, but it probably won't.
> 
>Hugo.
> 
> -- 
> Hugo Mills | Be pure.
> hugo@... carfax.org.uk | Be vigilant.
> http://carfax.org.uk/  | Behave.
> PGP: 65E74AC0  |   Torquemada, Nemesis



> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies


-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com 

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive 
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com 

Being so tracked is for FARM ANIMALS and and extermination camps, 
but incompatible with living as a free human being. -RI Safir 2013


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel thread scheduling

[Ruben Safir]

On 03/22/2015 07:30 PM, nick wrote:
> I would recommend reading Chapters 3 and  4 of Linux Kernel Development by 
> Robert Love
> as when I was learning the scheduler and process management


how much has the scheduler changed since then.  It was completely
overhauled when the CFS was created



___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel thread scheduling

[Ruben Safir]

On 04/10/2015 09:09 AM, nick wrote:
> 
> 
> On 2015-04-09 11:37 PM, Ruben Safir wrote:
>> On 04/09/2015 10:52 PM, nick wrote:
>>> Before asking questions again like this please look into either using lxr 
>>> or ctags
>>> to navigate the kernel tree for answers as can be faster then waiting for 
>>> me or 
>>> someone else to respond.
>>
>>
>> well, I reading the text is ctags aren't much value there.
>>
> Ctags is useful for searching the code, which is why I am recommending it.
> Nick

I have it built into gvim, but you can't use it from a textbook.  I'm
finding it is not as useful as it could be for the kernel code.  There
are stacks of tags to get around.  Another 2 days to learn to get around
tags in vi is not in the agenda right now.  It is the tool I have so
I'll have to live with it right now.

I also have a question that is not obvious from the code I'm looking at.
 I'm not sure how these structs are attached together.  Or more
specifically, I'm not sure how pulling the correct sched_entity gets one
the coresponding task_entity

You have
struct task_struct with a
struct sched_entity

struct sched_enitities are nodes in the RB tree
which are a "container" for "struct rb_node run_node".

So a look at sched_entity ... is in ../linux/sched.h

1161 struct sched_entity {
1162struct load_weight   load;/* for load-balancing */
1163struct rb_noderun_node;
1164struct list_head  group_node;
1165unsigned int  on_rq;
1166
1167u64 exec_start;
1168u64 sum_exec_runtime;
1169u64 vruntime;
1170u64 prev_sum_exec_runtime;
1171
1172u64 nr_migrations;
1173
1174 #ifdef CONFIG_SCHEDSTATS
1175struct sched_statistics statistics;
1176 #endif
1177
1178 #ifdef CONFIG_FAIR_GROUP_SCHED
1179int depth;
1180struct sched_entity  *parent;
1181/* rq on which this entity is (to be) queued: */
1182struct cfs_rq *cfs_rq;
1183/* rq "owned" by this entity/group: */
1184struct cfs_rq *my_q;
1185 #endif
1186
1187 #ifdef CONFIG_SMP
1188/* Per-entity load-tracking */
1189struct sched_avg  avg;
1190 #endif
1191 };

I see no means of referencing a specific task from this struct that
forms the node.  So when you pull the node with the smallest vruntime
from the left most postion of the RB tree, by calling pick_next_task(),


static struct sched_entity *__pick_next_entity(struct sched_entity *se)
{
struct rb_node *next = rb_next(&se->run_node);

if (!next)
return NULL;

return rb_entry(next, struct sched_entity, run_node);
}


how do we know what task we are attached to?

Ruben




>> ___
>> Kernelnewbies mailing list
>> Kernelnewbies@kernelnewbies.org
>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>>
> 
> 


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel thread scheduling

[Ruben Safir]

On 04/11/2015 10:21 PM, Ruben Safir wrote:
> On 04/10/2015 09:09 AM, nick wrote:
>>
>>
>> On 2015-04-09 11:37 PM, Ruben Safir wrote:
>>> On 04/09/2015 10:52 PM, nick wrote:
>>>> Before asking questions again like this please look into either using lxr 
>>>> or ctags
>>>> to navigate the kernel tree for answers as can be faster then waiting for 
>>>> me or 
>>>> someone else to respond.
>>>
>>>
>>> well, I reading the text is ctags aren't much value there.
>>>
>> Ctags is useful for searching the code, which is why I am recommending it.
>> Nick
> 
> I have it built into gvim, but you can't use it from a textbook.  I'm
> finding it is not as useful as it could be for the kernel code.  There
> are stacks of tags to get around.  Another 2 days to learn to get around
> tags in vi is not in the agenda right now.  It is the tool I have so
> I'll have to live with it right now.
> 
> I also have a question that is not obvious from the code I'm looking at.
>  I'm not sure how these structs are attached together.  Or more
> specifically, I'm not sure how pulling the correct sched_entity gets one
> the coresponding task_entity
> 
> You have
> struct task_struct with a
>   struct sched_entity
> 
> struct sched_enitities are nodes in the RB tree
>   which are a "container" for "struct rb_node run_node".
> 
> So a look at sched_entity ... is in ../linux/sched.h
> 
> 1161 struct sched_entity {
> 1162struct load_weight   load;/* for load-balancing */
> 1163struct rb_noderun_node;
> 1164struct list_head  group_node;
> 1165unsigned int  on_rq;
> 1166
> 1167u64 exec_start;
> 1168u64 sum_exec_runtime;
> 1169u64 vruntime;
> 1170u64 prev_sum_exec_runtime;
> 1171
> 1172u64 nr_migrations;
> 1173
> 1174 #ifdef CONFIG_SCHEDSTATS
> 1175struct sched_statistics statistics;
> 1176 #endif
> 1177
> 1178 #ifdef CONFIG_FAIR_GROUP_SCHED
> 1179int depth;
> 1180struct sched_entity  *parent;
> 1181/* rq on which this entity is (to be) queued: */
> 1182struct cfs_rq *cfs_rq;
> 1183/* rq "owned" by this entity/group: */
> 1184struct cfs_rq *my_q;
> 1185 #endif
> 1186
> 1187 #ifdef CONFIG_SMP
> 1188/* Per-entity load-tracking */
> 1189struct sched_avg  avg;
> 1190 #endif
> 1191 };
> 
> I see no means of referencing a specific task from this struct that
> forms the node.  So when you pull the node with the smallest vruntime
> from the left most postion of the RB tree, by calling pick_next_task(),
> 
> 
> static struct sched_entity *__pick_next_entity(struct sched_entity *se)
> {
>   struct rb_node *next = rb_next(&se->run_node);
> 
>   if (!next)
>   return NULL;
> 
>   return rb_entry(next, struct sched_entity, run_node);
> }
> 
> 
> how do we know what task we are attached to?
> 
> Ruben
> 
> 

I'm still loss on how we know which taks_struct is being used but as a
side note, I found this also very puzzling

return rb_entry(next, struct sched_entity, run_node);
With help I ran it down to this:

http://lxr.free-electrons.com/source/include/linux/rbtree.h#L50

#define rb_entry(ptr, type, member) container_of(ptr, type, member)

which leads me to yet another macro

798 #define container_of(ptr, type, member) ({  \
799 const typeof( ((type *)0)->member ) *__mptr = (ptr);\
800 (type *)( (char *)__mptr - offsetof(type,member) );})


This is a use of macros I'd never seen before up close.  If anyone could
help me understand it, I'd appreciate it.

Ruben
> 
> 
>>> ___
>>> Kernelnewbies mailing list
>>> Kernelnewbies@kernelnewbies.org
>>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>>>
>>
>>
> 
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 
> 


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel thread scheduling

[Ruben Safir]

On 04/12/2015 12:16 AM, nick wrote:
> This finds the next node in the red black tree for  sched_enities.
> Basically rb_next finds the next node in the tree. The argument is 
> the rb_node structure embedded in the structure using a red black
> tree.


The problem is this


struct mystruc {
int a;
char * string;
} wonderful;

char * string2 = wonderful.string;



There is no way to know that string2 comes from wonderful.
That is the problem I have with the nodes

The node is an instance of sched_entity.  But unless there is a field
that says what task_entity it is embedded in, in of itself, there is no
way to know.  There is no 'this' C.

Obviously if does know.  I'll look at chapter 6

I'm also looking at this



static struct sched_entity *__pick_next_entity(struct sched_entity *se)
{
struct rb_node *next = rb_next(&se->run_node);

if (!next)
return NULL;

return rb_entry(next, struct sched_entity, run_node); <<==macro
}



The macro is:  I think:
http://lxr.free-electrons.com/source/include/linux/rbtree.h#L50

50 #define rb_entry(ptr, type, member) container_of(ptr, type, member)

container_of is
http://lxr.free-electrons.com/source/include/linux/kernel.h#L798


791 /**
792  * container_of - cast a member of a structure out to the containing
structure
793  * @ptr:the pointer to the member.
794  * @type:   the type of the container struct this is embedded in.
795  * @member: the name of the member within the struct.
796  *
797  */
798 #define container_of(ptr, type, member) ({  \
799 const typeof( ((type *)0)->member ) *__mptr = (ptr);\
800 (type *)( (char *)__mptr - offsetof(type,member) );})


Now I have embedded macros which I thought you couldn't even do...

In trying to understand this I stumbled on

http://linuxkernel51.blogspot.com/2011/02/how-containerof-macro-works-example.html
 How "container_of" macro works, & an Example
Here iam giving a small code snippet that gives and idea about working
of "container_of", this posed me little difficulty in understanding,
after google-ing i got some examples and after working on that i wrote a
simple C application that depicts its working. here i have defined two
macros "offsetof" and "container_of" which i have extracted from
"kernel.h" header.
   Please interpret this code and try some trick to understand
"container_of".

container_of macro is defined in linux/kernel.h

syntax: container_of( pointer, container_type, container_field );

This macro takes a pointer to a filed name container_field, within a
structure of type container_type, and returns a pointer to the
containing structure .

simply this is a convenience macro that may be used to obtain a pointer
to a structure from a pointer to some other structure contained with in it.


Code :

#include 
#include 

#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)

#define container_of(ptr, type, member) ({\
 const typeof( ((type *)0)->member ) *__mptr = (ptr);\
 (type *)( (char *)__mptr - offsetof(type,member) );})

struct test1 {
 int a;
};

struct test2 {
 int b;
 struct test1 z;
 int c;
};

int main()
{
 /* existing structure */
 struct test2 *obj;
 obj = malloc(sizeof(struct test2));
 if(obj == NULL){
   printf("Error: Memory not allocated...!\n");
 }
 obj->z.a = 51;
 obj->b = 43;
 obj->c = 53;

 /* pointer to existing entry */
 struct test1 *obj1 = &obj->z; //both of type test1

 struct test2 *obj2 = container_of(obj1, struct test2, z);

 printf("obj2->b = %d\n", obj2->b); ///notsure what this does,need a nap

 return EXIT_SUCCESS;
}




___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel thread scheduling

[Ruben Safir]

On 04/12/2015 12:36 AM, Mohammed Ghriga wrote:
> In addition to the suggestions that were offered, I recommend you try reading 
> Chapter 16: https://www.google.com/search?tbo=p&tbm=bks&q=isbn:0596554672 
> (pages: 267-272). 
> 

http://it-ebooks.info/book/481/

FWIW I found this lovely wait example in the other kernel text under the
scheduling section

Sleeping and Waking Up page 58 in Robert Love, Linux Kernel Development

http://www.it-ebooks.info/book/819/


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Heap Management Problem

[Ruben Safir]

On 04/15/2015 12:28 AM, 慕冬亮 wrote:
> Can you give a detail of what you want to prove?
> I am not familiar with heap management , so I ask for the details!
> mudongliang
> 
> 2015-04-15 0:00 GMT+08:00 :
> 
>> On Tue, 14 Apr 2015 23:01:58 +0800, 慕冬亮 said:
>>
>>> Hello Everyone:
>>>   What's the rule about heap management? Especially what's the
>> function
>>> of do_brk?
>>
>> Who says there's a "rule" about it? Some userspace heap managers don't
>> even *use* brk() or sbrk(), but instead use mmap() of an anonymous area.
>>
> 
> 

To the OP, what in your mind is a Heap?

Ruben

> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Heap Management Problem

[Ruben Safir]

On Wed, Apr 15, 2015 at 05:10:05PM +0800, 慕冬亮 wrote:
> IMO, heap , stack , code ,data  and so on constitute the process address
> space!
>|
>|
> heap
> 
> stack
>|
>|
> data
> code
> So I only point to this heap !
> 

That is not nearly complete.  The Heap a memory structure attahced to
the processor control record that has pointers to areas in the memory
which are defined ad hoc in user space and are not defined in the PCR.

I can be wrong though.

Heaps can be allorthims which are nearly complete binrary trees with
values stored at nodes.

FWIW, that is tonights class for me...


> 2015-04-15 16:48 GMT+08:00 Ruben Safir :
> 
> > On 04/15/2015 12:28 AM, 慕冬亮 wrote:
> > > Can you give a detail of what you want to prove?
> > > I am not familiar with heap management , so I ask for the details!
> > > mudongliang
> > >
> > > 2015-04-15 0:00 GMT+08:00 :
> > >
> > >> On Tue, 14 Apr 2015 23:01:58 +0800, 慕冬亮 said:
> > >>
> > >>> Hello Everyone:
> > >>>   What's the rule about heap management? Especially what's the
> > >> function
> > >>> of do_brk?
> > >>
> > >> Who says there's a "rule" about it? Some userspace heap managers don't
> > >> even *use* brk() or sbrk(), but instead use mmap() of an anonymous area.
> > >>
> > >
> > >
> >
> > To the OP, what in your mind is a Heap?
> >
> > Ruben
> >
> > >
> > > ___
> > > Kernelnewbies mailing list
> > > Kernelnewbies@kernelnewbies.org
> > > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> > >
> >
> >
> > ___
> > Kernelnewbies mailing list
> > Kernelnewbies@kernelnewbies.org
> > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> >

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com 

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive 
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com 

Being so tracked is for FARM ANIMALS and and extermination camps, 
but incompatible with living as a free human being. -RI Safir 2013


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel thread scheduling

[Ruben Safir]

I'm trying to find rb_node's structure and I can't find it with ctags or
in the http://lxr.linux.no website.


How do you search these things out?


Ruben

On Thu, Apr 09, 2015 at 10:52:03PM -0400, nick wrote:
> 
> 
> On 2015-04-09 10:12 PM, Ruben Safir wrote:
> > On 04/09/2015 10:00 PM, nick wrote:
> >>
> >>
> >> On 2015-04-09 09:51 PM, Ruben Safir wrote:
> >>>
> >>> It is passover so I've read over much of this text, but I have to say
> >>> that in general, I'm way ahead of this book.  Although I have limited
> >>> knowledge of Kernel technology in the specific, the C code, data
> >>> structs, and programming concepts are spoon feed in this text and its
> >>> wasting too much time with words that are more easily explained with
> >>> coding examples and UML charts.  I don't need a chapter explaining how
> >>> to use ps and the basis of Unix architecture.  This text is targeted to
> >>> a different audience, and FWIW, I'm not certain it does a good job of
> >>> that either.  The guys who write these texts fall in love with their own
> >>> voices.  I know, I've suffered this disease myself when I've written
> >>> tech articles and books.
> >>>
> >>> I can''t recommend this book to anyone.  Anyone who doesn't understand
> >>> the basics of I/O processer blocks is not going to understand
> >>>
> >>> static void update_curr(struct cfs_rq *cfs_rq)
> >>>
> >>>
> >>> and OTOH void update_curr(struct cfs_rq *cfs_rq) is not explained well
> >>> enough for coders unfamiliar with the kernel data structs of which BTW
> >>> struct cfs_rq is not one defined in the text.
> >>>
> >>> :(
> >>>
> >>> I'm looking for something more like this, but flushed out more as a 
> >>> textbook
> >>>
> >>> http://www.ibm.com/developerworks/library/l-completely-fair-scheduler/index.html,
> >>> and some mentoring, I hope.
> >>>
> >>>
> >>> Ruben
> >>>
> 
> >> Ruben,
> >> The book is for an intro to the kernel not a complete walk through of each 
> >> subsystem.
> >> If that is the case,why not read the subsystem code and docs in the 
> >> kernel. I am a
> >> novice myself in terms of patch and coding experience but will be glad to 
> >> explain the
> >> code as I have read lots of it.
> > 
> > 
> > Thank you nick.  Yes, I downloaded the entire source from Kernel.org and
> > it is sitting on both my laptop and in virtual machines where I have
> > already compiled some stuff and not broken my VMs yets :)
> > 
> > I'm looking over  /home/ruben/linux-3.19.3/Documentation/scheduler
> > [ruben@stat13 scheduler]$ ls
> > 
> > 00-INDEX   sched-deadline.txt sched-rt-group.txt
> > media=legal -o sides=two-sided-long-edg  sched-design-CFS.txt
> > sched-stats.txt sched-arch.txt sched-domains.txt
> > sched-bwc.txt   sched-nice-design.txt
> > 
> > 
> > I also see in the code there is significant documentation.
> > 
> > Right now I am trying to figure out what is the relationship between
> > struct sched_entity and
> > struct cfs_rq and
> > struct rq_of
> > 
> > why do we have both??
> > 
> The way that these structures  are related is sched_enity is the entity for 
> the task's scheduling
> information or the task_struct of the a excuting process to be exact. 
> Furthermore  cfs_rq is the
> runquenue on which the task is running or selected to run on by schedule,the 
> main scheduling function
> of the kernel. Finally here is the function definition for rq_of to answer 
> your question,
> static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
> {
>   return cfs_rq->rq;
> }
> Before asking questions again like this please look into either using lxr or 
> ctags
> to navigate the kernel tree for answers as can be faster then waiting for me 
> or 
> someone else to respond.
> Thanks,
> Nick
> > there is a cast in update_curr
> > u64 now = rq_of(cfs_rq)->clock;
> > 
> > or is rq_of a function that returns a pointer is a struct that I missed?
> > 
> > 
> > 
> > 
> > 
> >> Nick
> >>> On 03/22/2015 08:35 PM, nick wrote:
> >>>>
> >>>>
> >>>> On 2015-03-22 08:05 PM, Ruben Safir wrote:
>

Re: Kernel thread scheduling

[Ruben Safir]

On 04/16/2015 11:07 AM, Ricardo Ribalda Delgado wrote:
> On Thu, Apr 16, 2015 at 4:56 PM, Ruben Safir  wrote:
>> I'm trying to find rb_node's structure and I can't find it with ctags or
>> in the http://lxr.linux.no website.
>>
>>
>> How do you search these things out?
> 
> 
> When everything else fails, I use grep
> 
> ricardo@neopili:~/curro/qtec/qt5022/kernel-cesium$ git grep " rb_node
> {" include/
> include/linux/rbtree.h:struct rb_node {
> ricardo@neopili:~/curro/qtec/qt5022/kernel-cesium$
> 
> 
> 


yeah ...

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel thread scheduling

[Ruben Safir]

On 04/16/2015 11:07 AM, Ricardo Ribalda Delgado wrote:
> On Thu, Apr 16, 2015 at 4:56 PM, Ruben Safir  wrote:
>> I'm trying to find rb_node's structure and I can't find it with ctags or
>> in the http://lxr.linux.no website.
>>
>>
>> How do you search these things out?
> 
> 
> When everything else fails, I use grep
> 
> ricardo@neopili:~/curro/qtec/qt5022/kernel-cesium$ git grep " rb_node
> {" include/
> include/linux/rbtree.h:struct rb_node {
> ricardo@neopili:~/curro/qtec/qt5022/kernel-cesium$
> 
> 
> 


although in theory that only works if all your defined files are in your
current subtree

I wish I understood what the tags file says.  It is like autoconf.  It
can take a lifetime to master the syntax.

Ruben

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel thread scheduling

[Ruben Safir]

On 04/16/2015 11:10 AM, Aruna Hewapathirane wrote:
>>> I'm trying to find rb_node's structure and I can't find it with ctags or
>>> in the http://lxr.linux.no website.
> 
> Please use this: Linux 2.6.11 and later 
> 


91 responses is not a useful search...



___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel thread scheduling

[Ruben Safir]

On 04/16/2015 12:31 PM, Jeff Haran wrote:
>> From: kernelnewbies-boun...@kernelnewbies.org 
>> [mailto:kernelnewbies-boun...@kernelnewbies.org] On Behalf Of Mark P
>> Sent: Thursday, April 16, 2015 8:12 AM
>> To: Ruben Safir
>> Cc: nick; kernelnewbies@kernelnewbies.org
>> Subject: Re: Kernel thread scheduling
>>
>> I find that the free electrons LXR has the best search capabilities:
>>
>> http://lxr.free-electrons.com/source/include/linux/rbtree.h#L35
>> -M
> 
> Those interested in kernel source browsers might want to check out the code 
> browser available at https://scan.coverity.com.
> 
> Coverity does static code analysis and sells a product to do so, but they do 
> regular scans of popular open source projects. Most of their focus is on 
> finding and reporting defects, but the code browser they have created to do 
> so is far beyond anything else I've found out there. Getting to it is a 
> little awkward, you first need to sign up for an account (I got mine for 
> free), then browse to the linux kernel project and select a defect to get 
> into the browser. But once there, click the folder icon at the top left of 
> the code window and select a source file. All of function names, variable 
> names, structure names and structure field names are hyperlinks. Left click 
> on one of them, click the little down arrow and select from the menu to list 
> definitions, references, etc.
> 
> You do need to find a reference to the token in question using some other 
> browser like LXR, Coverity's doesn't seem to have a search button for that, 
> but once located the cross-referencing provided is better than what I've seen 
> in other text matching browsers like LXR, cscope, etc. It's particular good 
> when you are trying to understand how a given field of a structure is used. 
> Say you want to find out how a structure field named "lock" in some structure 
> named "foo" is referenced. Find the definition of struct foo, click on the 
> lock field and list references. It will show all the references to struct 
> foo's lock but NOT show the thousands of references to all of the other 
> fields named "lock" in other structures. That is something no other browser 
> does, at least none that I am aware of.
> 
> Jeff Haran
> 



Is it free software?  Can I download it?
How is it better than grep and sed?
Does it work better than ctags?
How can I get it to ingrate with vim?

First off, if it is not available as free Software, then I won't use it.


> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 
> 


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel thread scheduling

[Ruben Safir]

>  
> > First off, if it is not available as free Software, then I won't use it.
> 
> That is of course your choice to make. 


And it is the correct decision to make.  People who make another
decision would not care about the damage they do to themselves and
others by promoting the use of a proprietary system to access and learn
about a free software project devised to intentionally do just the
opposite and to give people access to code and ownership of their
digital system.

Why would someone sell that freedom for a minor convenience. 

This has been hashed.  If everyone depended on this Software as a
Service then you would have a nice walled garden to the Kernel Code.
That would be a nice for you __maybe__, but it would be bad for the rest
of us.

https://www.gnu.org/philosophy/who-does-that-server-really-serve.html 

>> Others may come to different conclusions. I use www.google.com on a regular 
>> basis even though I can't download it.
> 

That is not even a good analogy.  But for what it is worth, SOS is
killing free software on the google platform altogether and it is a
tragedy...  it is killing Free Software and choking the future of
development.





> Jeff Haran
> 
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com 

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive 
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com 

Being so tracked is for FARM ANIMALS and and extermination camps, 
but incompatible with living as a free human being. -RI Safir 2013


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel thread scheduling

[Ruben Safir]

On 04/16/2015 02:32 PM, John de la Garza wrote:
> On Thu, Apr 16, 2015 at 10:56:46AM -0400, Ruben Safir wrote:
>> I'm trying to find rb_node's structure and I can't find it with ctags or
>> in the http://lxr.linux.no website.
>>

THANK YOU - This is for my archive of useful Linux Hints!!
>>
>> How do you search these things out?
> 
> I run:
>   make ctags
> 
> run vim
> 
> type:
>   :ts rb_node
> 
> then I scanned the list for things that are from include/linux
> 
> and found this
>  20 F   srb_node   include/linux/rbtree.h
>struct rb_node {
> 
> I select 20 and it takes me to include/linux/rbtree.h
> 
> and puts me at the line containing this:
> 
>   struct rb_node {
>   unsigned long  __rb_parent_color;
>   struct rb_node *rb_right;
>   struct rb_node *rb_left;
>   } __attribute__((aligned(sizeof(long;
> /* The alignment might seem pointless, but allegedly CRIS needs it */
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 
> 


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel thread scheduling

[Ruben Safir]

On 04/16/2015 02:32 PM, John de la Garza wrote:
> On Thu, Apr 16, 2015 at 10:56:46AM -0400, Ruben Safir wrote:
>> I'm trying to find rb_node's structure and I can't find it with ctags or
>> in the http://lxr.linux.no website.
>>
>>
>> How do you search these things out?
> 


That is truly beautiful.  Is that documented anywhere in plain english?

Ruben

> I run:
>   make ctags
> 
> run vim
> 
> type:
>   :ts rb_node
> 
> then I scanned the list for things that are from include/linux
> 
> and found this
>  20 F   srb_node   include/linux/rbtree.h
>struct rb_node {
> 
> I select 20 and it takes me to include/linux/rbtree.h
> 
> and puts me at the line containing this:
> 
>   struct rb_node {
>   unsigned long  __rb_parent_color;
>   struct rb_node *rb_right;
>   struct rb_node *rb_left;
>   } __attribute__((aligned(sizeof(long;
> /* The alignment might seem pointless, but allegedly CRIS needs it */
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 
> 


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel thread scheduling

[Ruben Safir]

On 04/16/2015 02:47 PM, valdis.kletni...@vt.edu wrote:
> We're comparing closed Coverty-as-a-service with closed Google-as-a-service.
> Seems like a good analogy to me.


well it isn't.  It is not demonizing them to state the facts.  First of
all, search engines do something you can't do with software, which is
crawl the internet.  The correct analogy is what google is doing with
android, which indeed is repulsive because it is inhibiting access and
development on the platform, and then worse than that, claiming that it
is all "open" when really it is not.



http://arstechnica.com/gadgets/2013/10/googles-iron-grip-on-android-controlling-open-source-by-any-means-necessary/


I have the source code for the kernel here.  If Coventry would be
interested in selling me a free software of their application, I might
be interested.  But I'm not interested in putting kernel tools behind
slavewalls.  That is exactly the opposite of what I want to do and
defies my very Raison E'Stat for studying the Linux Kernel

nono.  If you find this Demonizing, it is not I who does this, it is
facts stated forthrightly and dispassionately.  Someone who uses closed
proprietary  software as a service to access the Linux Kernel Source is
cutting off the very air to free software development by supporting
non-free tools that compete with free tools in learning about the source
code.  Using free software tools is not a technological decision.  It is
a political decision (as all decisions ultimately are).  It is a
decision to exercise freedom over a __lack__ of freedom.

Aside from that, the question of google is irrelevant to this
conversation and is just a distraction.  Tow wrongs don't make a right.
 A company that has a search engine that uses published free software
would be much more desirable than one that doesn't do that.  No one
wants to penalize anyone for selling software services.  But that is not
reason to abandon free software tools for the studying of the kernel in
order to adopt a proprietary scheme of secret software sold as a
service.  That would just be irrational.

Ruben



___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel thread scheduling

[Ruben Safir]

> 
> And just for the record, I have no financial interest in Coverity or its 
> parent company. I've been a user of their system at a couple of companies 
> I've worked for now, but that and my usage of their free service is the only 
> connection I have with them.
> 
> Jeff Haran


Jeff, FWIW, I have no objection to a financial interest.  I want you to
make as much many as you can

This is not an issue of money.

Ruben

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com 

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive 
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com 

Being so tracked is for FARM ANIMALS and and extermination camps, 
but incompatible with living as a free human being. -RI Safir 2013


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel thread scheduling

[Ruben Safir]

looking at it know because I have no clue what that macro is.

It is not listed as possible in kings


On Sun, Apr 12, 2015 at 04:36:53AM +, Mohammed Ghriga wrote:
> In addition to the suggestions that were offered, I recommend you try reading 
> Chapter 16: https://www.google.com/search?tbo=p&tbm=bks&q=isbn:0596554672 
> (pages: 267-272). 
> 
> 
> -Original Message-
> From: nick [mailto:xerofo...@gmail.com] 
> Sent: Sunday, April 12, 2015 12:16 AM
> To: Ruben Safir; kernelnewbies@kernelnewbies.org; Mohammed Ghriga
> Subject: Re: Kernel thread scheduling
> 
> 
> 
> On 2015-04-11 11:02 PM, Ruben Safir wrote:
> > On 04/11/2015 10:21 PM, Ruben Safir wrote:
> >> On 04/10/2015 09:09 AM, nick wrote:
> >>>
> >>>
> >>> On 2015-04-09 11:37 PM, Ruben Safir wrote:
> >>>> On 04/09/2015 10:52 PM, nick wrote:
> >>>>> Before asking questions again like this please look into either 
> >>>>> using lxr or ctags to navigate the kernel tree for answers as can 
> >>>>> be faster then waiting for me or someone else to respond.
> >>>>
> >>>>
> >>>> well, I reading the text is ctags aren't much value there.
> >>>>
> >>> Ctags is useful for searching the code, which is why I am recommending it.
> >>> Nick
> >>
> >> I have it built into gvim, but you can't use it from a textbook.  I'm 
> >> finding it is not as useful as it could be for the kernel code.  
> >> There are stacks of tags to get around.  Another 2 days to learn to 
> >> get around tags in vi is not in the agenda right now.  It is the tool 
> >> I have so I'll have to live with it right now.
> >>
> >> I also have a question that is not obvious from the code I'm looking at.
> >>  I'm not sure how these structs are attached together.  Or more 
> >> specifically, I'm not sure how pulling the correct sched_entity gets 
> >> one the coresponding task_entity
> >>
> >> You have
> >> struct task_struct with a
> >>struct sched_entity
> >>
> >> struct sched_enitities are nodes in the RB tree
> >>which are a "container" for "struct rb_node run_node".
> >>
> >> So a look at sched_entity ... is in ../linux/sched.h
> >>
> >> 1161 struct sched_entity {
> >> 1162struct load_weight   load;/* for load-balancing */
> >> 1163struct rb_noderun_node;
> >> 1164struct list_head  group_node;
> >> 1165unsigned int  on_rq;
> >> 1166
> >> 1167u64 exec_start;
> >> 1168u64 sum_exec_runtime;
> >> 1169u64 vruntime;
> >> 1170u64 prev_sum_exec_runtime;
> >> 1171
> >> 1172u64 nr_migrations;
> >> 1173
> >> 1174 #ifdef CONFIG_SCHEDSTATS
> >> 1175struct sched_statistics statistics;
> >> 1176 #endif
> >> 1177
> >> 1178 #ifdef CONFIG_FAIR_GROUP_SCHED
> >> 1179int depth;
> >> 1180struct sched_entity  *parent;
> >> 1181/* rq on which this entity is (to be) queued: */
> >> 1182struct cfs_rq *cfs_rq;
> >> 1183/* rq "owned" by this entity/group: */
> >> 1184struct cfs_rq *my_q;
> >> 1185 #endif
> >> 1186
> >> 1187 #ifdef CONFIG_SMP
> >> 1188/* Per-entity load-tracking */
> >> 1189struct sched_avg  avg;
> >> 1190 #endif
> >> 1191 };
> >>
> >> I see no means of referencing a specific task from this struct that 
> >> forms the node.  So when you pull the node with the smallest vruntime 
> >> from the left most postion of the RB tree, by calling 
> >> pick_next_task(),
> >>
> >>
> >> static struct sched_entity *__pick_next_entity(struct sched_entity 
> >> *se) {
> >>struct rb_node *next = rb_next(&se->run_node);
> This finds the next node in the red black tree for  sched_enities.
> Basically rb_next finds the next node in the tree. The argument is the 
> rb_node structure embedded in the structure using a red black tree.
> >>
> >>if (!next)
> >>return NULL;
> >>
> If there is no runnable task return NULL and pick_next_task will run the 
> idle_task for this cpu.
> >>return rb_entry(next, struct sched_entity, run_node); }
> >>
> >>
> >> how do we know what task we are attached to

Re: Kernel thread scheduling

[Ruben Safir]

That is written by my friend GREG!!

I know Greg.  I've had many beers with Greg.

Ruben


On Sun, Apr 12, 2015 at 04:36:53AM +, Mohammed Ghriga wrote:
> In addition to the suggestions that were offered, I recommend you try reading 
> Chapter 16: https://www.google.com/search?tbo=p&tbm=bks&q=isbn:0596554672 
> (pages: 267-272). 
> 
> 
> -Original Message-
> From: nick [mailto:xerofo...@gmail.com] 
> Sent: Sunday, April 12, 2015 12:16 AM
> To: Ruben Safir; kernelnewbies@kernelnewbies.org; Mohammed Ghriga
> Subject: Re: Kernel thread scheduling
> 
> 
> 
> On 2015-04-11 11:02 PM, Ruben Safir wrote:
> > On 04/11/2015 10:21 PM, Ruben Safir wrote:
> >> On 04/10/2015 09:09 AM, nick wrote:
> >>>
> >>>
> >>> On 2015-04-09 11:37 PM, Ruben Safir wrote:
> >>>> On 04/09/2015 10:52 PM, nick wrote:
> >>>>> Before asking questions again like this please look into either 
> >>>>> using lxr or ctags to navigate the kernel tree for answers as can 
> >>>>> be faster then waiting for me or someone else to respond.
> >>>>
> >>>>
> >>>> well, I reading the text is ctags aren't much value there.
> >>>>
> >>> Ctags is useful for searching the code, which is why I am recommending it.
> >>> Nick
> >>
> >> I have it built into gvim, but you can't use it from a textbook.  I'm 
> >> finding it is not as useful as it could be for the kernel code.  
> >> There are stacks of tags to get around.  Another 2 days to learn to 
> >> get around tags in vi is not in the agenda right now.  It is the tool 
> >> I have so I'll have to live with it right now.
> >>
> >> I also have a question that is not obvious from the code I'm looking at.
> >>  I'm not sure how these structs are attached together.  Or more 
> >> specifically, I'm not sure how pulling the correct sched_entity gets 
> >> one the coresponding task_entity
> >>
> >> You have
> >> struct task_struct with a
> >>struct sched_entity
> >>
> >> struct sched_enitities are nodes in the RB tree
> >>which are a "container" for "struct rb_node run_node".
> >>
> >> So a look at sched_entity ... is in ../linux/sched.h
> >>
> >> 1161 struct sched_entity {
> >> 1162struct load_weight   load;/* for load-balancing */
> >> 1163struct rb_noderun_node;
> >> 1164struct list_head  group_node;
> >> 1165unsigned int  on_rq;
> >> 1166
> >> 1167u64 exec_start;
> >> 1168u64 sum_exec_runtime;
> >> 1169u64 vruntime;
> >> 1170u64 prev_sum_exec_runtime;
> >> 1171
> >> 1172u64 nr_migrations;
> >> 1173
> >> 1174 #ifdef CONFIG_SCHEDSTATS
> >> 1175struct sched_statistics statistics;
> >> 1176 #endif
> >> 1177
> >> 1178 #ifdef CONFIG_FAIR_GROUP_SCHED
> >> 1179int depth;
> >> 1180struct sched_entity  *parent;
> >> 1181/* rq on which this entity is (to be) queued: */
> >> 1182struct cfs_rq *cfs_rq;
> >> 1183/* rq "owned" by this entity/group: */
> >> 1184struct cfs_rq *my_q;
> >> 1185 #endif
> >> 1186
> >> 1187 #ifdef CONFIG_SMP
> >> 1188/* Per-entity load-tracking */
> >> 1189struct sched_avg  avg;
> >> 1190 #endif
> >> 1191 };
> >>
> >> I see no means of referencing a specific task from this struct that 
> >> forms the node.  So when you pull the node with the smallest vruntime 
> >> from the left most postion of the RB tree, by calling 
> >> pick_next_task(),
> >>
> >>
> >> static struct sched_entity *__pick_next_entity(struct sched_entity 
> >> *se) {
> >>struct rb_node *next = rb_next(&se->run_node);
> This finds the next node in the red black tree for  sched_enities.
> Basically rb_next finds the next node in the tree. The argument is the 
> rb_node structure embedded in the structure using a red black tree.
> >>
> >>if (!next)
> >>return NULL;
> >>
> If there is no runnable task return NULL and pick_next_task will run the 
> idle_task for this cpu.
> >>return rb_entry(next, struct sched_entity, run_node); }
> >>
> >>
> >> how do we know what task we are attached to?
> &g

wait queues

[Ruben Safir]

I'm not pouring over Love's book in detail and the section in Chapter 4
on the wit queue is implemented  in the text completely surprised me.

He is recommending that you have to right your own wait queue entry
routine for every process?  Isn't that reckless?

He is suggesting

DEFINE_WAIT(wait) //what IS wait

add_wait_queue(q, &wait); // in the current kernel this invovled
 //  flag   checking and a linked list

while(!condition){ /* an event we are weighting for
  prepare_to_wait(&q, &wait, TASK_INTERRUPTIBLE);
  if(signal_pending(current))
/* SIGNAl HANDLE */
  schedule();
}

finish_wait(&q, &wait);

He also write how this proceeds to function and one part confuses me

5.  When the taks awakens, it again checks whether the condition is
true.  If it is, it exists the loop.  Otherwise it again calls schedule.


This is not the order that it seems to follow according to the code.

To me it looks like it should
1 - creat2 the wait queue
2 - adds &wait onto queue q
3 checks if condition is true, if so, if not, enter a while loop
4 prepare_to_wait which changes the status of our &wait to
TASK_INTERUPPABLE
5 check for signals ... notice the process is still moving.  Does it
stop and wait now?
6  schedule itself on the runtime rbtree... which make NO sense unless
there was a stopage I didn't know about.
7 check the condition again and repeat while look
7a. if the loop ends fishish_waiting... take it off the queue.



Isn't this reckless to leave this to users to write the code.  Your
begging for a race condition.

Ruben

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

wait queues

[Ruben Safir]

I'm not pouring over Love's book in detail and the section in Chapter 4
on the wit queue is implemented  in the text completely surprised me.

He is recommending that you have to right your own wait queue entry
routine for every process?  Isn't that reckless?

He is suggesting

DEFINE_WAIT(wait) //what IS wait

add_wait_queue(q, &wait); // in the current kernel this invovled
 //  flag   checking and a linked list

while(!condition){ /* an event we are weighting for
  prepare_to_wait(&q, &wait, TASK_INTERRUPTIBLE);
  if(signal_pending(current))
/* SIGNAl HANDLE */
  schedule();
}

finish_wait(&q, &wait);

He also write how this proceeds to function and one part confuses me

5.  When the taks awakens, it again checks whether the condition is
true.  If it is, it exists the loop.  Otherwise it again calls schedule.


This is not the order that it seems to follow according to the code.

To me it looks like it should
1 - creat2 the wait queue
2 - adds &wait onto queue q
3 checks if condition is true, if so, if not, enter a while loop
4 prepare_to_wait which changes the status of our &wait to
TASK_INTERUPPABLE
5 check for signals ... notice the process is still moving.  Does it
stop and wait now?
6  schedule itself on the runtime rbtree... which make NO sense unless
there was a stopage I didn't know about.
7 check the condition again and repeat while look
7a. if the loop ends fishish_waiting... take it off the queue.



Isn't this reckless to leave this to users to write the code.  Your
begging for a race condition.

Ruben

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies



___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: wait queues

[Ruben Safir]

I assume this is a different wait then the one we covered in call for
concurrency.


On 04/19/2015 09:23 PM, Ruben Safir wrote:
> I'm not pouring over Love's book in detail and the section in Chapter 4
> on the wait queue is implemented  in the text completely surprised me.
> 
> He is recommending that you have to right your own wait queue entry
> routine for every process?  Isn't that reckless?
> 
> He is suggesting
> 
> DEFINE_WAIT(wait) //what IS wait
> 
> add_wait_queue(q, &wait); // in the current kernel this invovled
>  //  flag   checking and a linked list
> 
> while(!condition){ /* an event we are weighting for
>   prepare_to_wait(&q, &wait, TASK_INTERRUPTIBLE);
>   if(signal_pending(current))
> /* SIGNAl HANDLE */
>   schedule();
> }
> 
> finish_wait(&q, &wait);
> 
> He also write how this proceeds to function and one part confuses me
> 
> 5.  When the task awakens, it again checks whether the condition is
> true.  If it is, it exists the loop.  Otherwise it again calls schedule.
> 
> 
> This is not the order that it seems to follow according to the code.
> 
> To me it looks like it should
> 1 - create the wait queue
> 2 - adds &wait onto queue q
> 3 checks if condition is true, if not, enter a while loop
> 4 prepare_to_wait which changes the status of our &wait to
> TASK_INTERUPPABLE

see this here must mean that wait is something else?

> 5 check for signals ... notice the process is still moving.  Does it
> stop and wait now?
> 6  schedule itself on the runtime rbtree... which make NO sense unless
> there was a stopage I didn't know about.
> 7 check the condition again and repeat while look
>   7a. if the loop ends fishish_waiting... take it off the queue.
> 
> 
> 
> Isn't this reckless to leave this to users to write the code.  Your
> begging for a race condition.
> 
> Ruben
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 
> 
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 
> 


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: wait queues

[Ruben Safir]

On 04/19/2015 09:54 PM, Fred Chou wrote:
> Could this be a lost wake-up problem?

that is what it is supposed to solve.  It doesn't help to understand the
code though.

Ruben

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: How do _you_ read the linux source?

[Ruben Safir]

On 04/20/2015 12:32 PM, Jeff Haran wrote:
> I'll put in another plug for Coverity's source code browser here.
> 
> https://scan.coverity.com/
> 
> To use it you need to sign-up for an account, but that is free and it's much 
> better for browsing large projects than ctags, cscope, grep, etc., IMHO.


if you want to learn nothing and sit behind a proprietary software wall
to access your free software.



___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: How do _you_ read the linux source?

[Ruben Safir]

On Tue, Apr 21, 2015 at 02:16:49AM +0200, Milton Krutt wrote:
> > On Sun, Apr 19, 2015 at 06:57:49PM -0700, r0...@simplecpu.com wrote:
> > >   The problem a lot of newbies are having is in 'separating the trunk
> > > from the leaves.' So my question is this: Experienced kernel developers, 
> > > how
> > > do _you_ read source code? How do you separate the trunk from the leaves?
> > > What do you do when you read code you're not familiar with? How do you 
> > > learn?
> > > What's your algorithm?
> 
> Maybe it could help to firstly focus on data structures/types rather than 
> functions;
> and I would discourage to read code like a book, I mean from left to right and
> from top to bottom. And, take a subsystem/part (even if it's very small) of 
> interest
> and just focus on it. For instance, I guess there is plenty of documentation 
> on how
> linux boots up: read it, and search through the source where what you have 
> read is done.
> 


Booting is so messed up that it might not be the place to start.  Asking
how to read the code is a non-sensible question.  Its like asking how do
you speak French.  The answer is, I speak it.  You don't know how to
speak it?  Well staring at incomrehesible code aint helping you any.

It requires one to interact with it, and that requires background.  

So the question is, I just do and if I can't understand it I roll up my
sleeves and research, ask, discuss, and work with it.

There is no forrest... there is no trees.  

> compile your own kernel, if you haven't done it yet!
> 
> HTH
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com 

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive 
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com 

Being so tracked is for FARM ANIMALS and and extermination camps, 
but incompatible with living as a free human being. -RI Safir 2013


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: process tracking

[Ruben Safir]

On Mon, Apr 20, 2015 at 11:58:17PM +0200, Mustafa Hussain wrote:
> I have reading recently how CFS works and I want to detect processes that
> is not used and have the policy SCHED_NORMAL,
> 
> Can i do this by tracking load_weight for each process if the load dose not
> change over the time can i consider this process is not used ?

it has nothing to do with the load_weight.  I can be corrected on this
but it is configuration.

There are functions that can be coded that adjust the class of priority
for a thread or process such as 

/**
 * sched_setscheduler - change the scheduling policy and/or RT priority
 * of a thread.
 * @p: the task in question.
 * @policy: new policy.
 * @param: structure containing the new RT priority.
 *
 * Return: 0 on success. An error code otherwise.
 *
 * NOTE that the task may be already dead.
 */
int sched_setscheduler(struct task_struct *p, int policy,
   const struct sched_param *param)
{
return _sched_setscheduler(p, policy, param, true);
}
EXPORT_SYMBOL_GPL(sched_setscheduler);

in linux/kernel.sched/core.c


download the Kernel Source Code and take a look

Ruben


> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies


-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com 

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive 
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com 

Being so tracked is for FARM ANIMALS and and extermination camps, 
but incompatible with living as a free human being. -RI Safir 2013


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: process tracking

[Ruben Safir]

On 04/21/2015 01:09 PM, Mustafa Hussain wrote:
> in fact i don't need to change the policy of the process, 


you missed the point.  Anyway, this list is really about learning the
kernel and not tech support.  You might get better responses on usenet.

Ruben

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: wait queues semiphores kernel implementations

[Ruben Safir]

Ruben QUOTED Previously:

<<>



On 04/21/2015 11:05 AM, mic...@michaelblizek.twilightparadox.com wrote:
> Hi!
> 
> On 12:39 Mon 20 Apr , Ruben Safir wrote:
>> On 04/20/2015 11:23 AM, mic...@michaelblizek.twilightparadox.com wrote:
>>> I would not recommend that. There are already functions in linux/wait.h for
>>> these purposes like wait_event_interruptible(). 
>>
>>
>> can you do that in the kernel?  The wait_event_interuptable creates wait
>> queues?
> 
> No, wait_event_interuptable waits on an existing waitqueue. If you want to
> create a waitqueue, call init_waitqueue_head().
> 
>   -Michi
> 


Here is the confusing part.  this is a discussion on wait and semiphores
in a standard text

5.6.2
 Semaphore Implementation
Recall that the implementation of mutex locks discussed in Section 5.5
suffers from busy waiting. The definitions of the wait() and signal()
semaphore operations just described present the same problem. To
overcome the need for busy waiting, we can modify the definition of the
wait() and signal() operations as follows: When a process executes the
wait() operation and finds that the semaphore value is not positive, it
must wait. However, rather than engaging in busy waiting, the process
can block itself. The block operation places a process into a waiting
queue associated with the semaphore, and the state of the process is
switched to the waiting state. Then control is transferred to the CPU
scheduler, which selects another process to execute.

A process that is blocked, waiting on a semaphore S, should be restarted
when some other process executes a signal() operation. The process is
restarted by a wakeup() operation, which changes the process from the
waiting state to the ready state. The process is then placed in the
ready queue. (The CPU may or may not be switched from the running
process to the newly ready process, depending on the CPU-scheduling
algorithm.)

To implement semaphores under this definition, we define a semaphore as
follows:

typedef struct {
int value;
struct process *list;
} semaphore;

Each semaphore has an integer value and a list of processes list. When
a process must wait on a semaphore, it is added to the list of processes. A
signal() operation removes one process from the list of waiting
processes and awakens that process.
Now, the wait() semaphore operation can be defined as

wait(semaphore *S) {
   S->value--;
  if (S->value < 0) {
  add this process to S->list;
  block();
  }
}

and the signal() semaphore operation can be defined as

signal(semaphore *S) {
  S->value++;
  if (S->value <= 0) {
  remove a process P from S->list;
  wakeup(P);
  }
}


Minus the Semiphore, that sounds like what we are doing with the wait
list in the scheduler.   But it looks like we are leaving it to the
user.  Why?  It is similar but oddly different so I'm trying to figure
out what is happening here.

Ruben


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Semaphore and Spinlock

[Ruben Safir]

On 04/27/2015 09:18 AM, Abhishek Bist wrote:
> [ Semaphores are a bit like spinlocks, except the holder of a semaphore is a 
> process, not a CPU. ]
> This is a very first line that is bein written on the description of 
> semaphore on kernel newbies.So what are the different parameter 
> that could justify this statement or the way it could be justified and 
> understood.
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 
> 


That is a good question.  In fact, I've been studying semaphores,
spinlocks and Mutexes now for 3 weeks and it still confuses me.  Our
school is working from a text called Operating Systems Concepts 9th
Edition.  It seems to avoid defining things

It should say

Definition:
Semephore
Mutex:
Spinlocks:

and then there is monitors

I have poured over a lot of sample code.  I can show you coding examples
for concurrence protection from race condition, and models for mutexes,
and even describe what a wait queue might look like, but in the end, I'm
still puzzled by this most basic of definition.  A lot of this is the
fault of the book.  They get lost in their own words, research and
thoughts and fail to deliver understand concepts to the student.

Forget operating systems.  Lets say I am writing a book about Bicycles
and the principles of Bicycle design.  And we are going to study wheels.
 It makes for very ineffective communication to spend 10 pages
describing that C=2piR and other facts about circle geometry, and the
mathematical calculation of force when applied to a spoke(or a rope)
under tension, et et et and forget to define that a Wheel on a bicycle
is a round hoop, usually covered on the outer rim by a rubber tire, that
makes contact to the road and allows for the bicycle to roll.





___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: running queue processes

[Ruben Safir]

On 05/03/2015 08:47 AM, Nicholas Krause wrote:
> remember there being information about this topic being in the Linux 
> programming interface in chapters 26 through 28. Furthermore find a copy of 
> this book as it's a rather good reference for when you need questions like 
> this answered. 


which book?

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel contributions from organisations and individual privacy

[Ruben Safir]

On 06/11/2015 01:10 AM, Chris Packham wrote:
> It's not a concern for the _employer


If the copyright is owned by the company then ONLY the company can push
it up stream and assign copyright to the Linux Foundation.  But there is
an inherent problem and it sort of bothers me which is why I'm responding.

It may be the case that someone can not keep their identity a secret and
contribute to the kernel.  If you want to keep your identity a secret
there are a WHOLE SLEW of things you can't do because they require
public identification.  It is NOT true that they can't contribute to the
kernel because they "value" their privacy.  They can not contribute
because it is a PUBLIC act and LEGAL public act.  And you can't do this,
perhaps, anymore than you could run for office anonymous, or take an
active roll in any political activity.  And that is good thing.


Ruben

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel contributions from organisations and individual privacy

[Ruben Safir]

On 06/11/2015 10:28 AM, Greg KH wrote:
>> If the copyright is owned by the company then ONLY the company can push
>> > it up stream and assign copyright to the Linux Foundation.
> No one assigns kernel copyright to the Linux Foundation unless you have
> entered into some odd business agreement with that legal entity.  And
> that is quite rare to do so and takes lots of lawyers and time.


It doesn't take a lot of lawyers anymore than a license would.  I
thought that the Foundation requests this routinely in order so that it
has standing in court if a lawsuit should happen.  The FSF has copyright
to a large bulk of the software under GNU for this reason.
Obviously you have first hand knowledge of practice I don't have, but
copyright is a huge problem with contrition.  In order to contribute,
you must have copyright ownership.  You can't prove that if your anonymous.

Ruben

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel contributions from organisations and individual privacy

[Ruben Safir]

On 06/11/2015 11:38 AM, Greg KH wrote:
> On Thu, Jun 11, 2015 at 10:41:57AM -0400, Ruben Safir wrote:
>> On 06/11/2015 10:28 AM, Greg KH wrote:
>>>> If the copyright is owned by the company then ONLY the company can push
>>>>> it up stream and assign copyright to the Linux Foundation.
>>> No one assigns kernel copyright to the Linux Foundation unless you have
>>> entered into some odd business agreement with that legal entity.  And
>>> that is quite rare to do so and takes lots of lawyers and time.
>>
>>
>> It doesn't take a lot of lawyers anymore than a license would.  I
>> thought that the Foundation requests this routinely in order so that it
>> has standing in court if a lawsuit should happen.
> 
> No, it never has done this, where are you getting this crazy idea?


This idea is not crazy.  During the SCO battle this problem got tossed
about quite a bit and I thought that at that time the Linux Foundation
and Mad Dog set up a Copyright Clearing House for the Kernel.  Your
saying that this never happened, so maybe I'm wrong.  But it was
discussed a lot, and lawyers were involvedand Linus was involved.

The problem is two fold.  First the Foundation and Linus need standing
in court cases where violations of the GPL2 were involved...if there was
such need.  That is best established with assignment of the copyright,
bit done through a contributor license agreement.

I never claimed, BTW, that this was forced on everyone.  But I thought
it was encouraged since the SCO battle.

Secondly, it prevents what SCO actually claimed they could do, which is
pull there code, and the derivative works, from the kernel altogether.
If the contributor assigned copyright, that is better than depending on
the GPL2 guarantees of relicensurethe so called viral aspect of the
GPL, which is the part that actually guarantees that a shared
contribution project like the linux kernel can exist securely under
copyright law.


BTW - the crazy idea came from a conversation I had with Linus when I
talked to him about the MYSQL license, fwiw, and then I bounced it off
of Moglin, who referred me to Sara Brown, who put me in touch with
Richard...and the the SCO thing broke out and then the conversation was
all over slashdot and then moved the Wall Street Journal..and then IBM
got involved and that is when I thought the TLF set up a CLA, but it
must have only set up the little sworn statement you posted.

OK - the earth will still spin on its axis today.

I do not want to put out misinformation.  Thank You for the correction ;)


> 
> The only thing you have to agree with when contributing Linux kernel
> code is the DCO, which can be found in the file
> Documentation/SubmittingPatches, or here online:
>   http://developercertificate.org/
> 

I didn't know that and looking at it, that is pretty flimsy.  It is a
good thing that up until know this hasn't bit them in the ass so far.  I
might be all that is possible though because a CLA, to be really
blanket, would require one having to go back to every contribution to
date.  So it is a limited device.  But it was discussed and I did talk
to Mad Dog about it years ago.


> You keep your copyright on the contribution you make, it's always been
> that way for Linux kernel development for its entire development history
> (22+ years).  I don't know where you got the idea that you have to
> assign copyright away to contribute to the kernel, but please do not
> spread false information like this.
> 
>> The FSF has copyright to a large bulk of the software under GNU for
>> this reason.
> 
> The FSF is insane, don't confuse the two groups please :)
>

That might be so, but with regard to CLAs, I think they have it right.


>> Obviously you have first hand knowledge of practice I don't have, but
>> copyright is a huge problem with contrition.
> 
> "contrition"?  The state of feeling regret?  What are you talking about?
> 

Don't you LOVE spell checkers!  contributions

>> In order to contribute, you must have copyright ownership.  You can't
>> prove that if your anonymous.
> 
> Which is why we can not accept anonymous contributions to the Linux
> kernel.
>


Right which is the core point.

> But then there's the technical aspect of it all.  When you put your name
> on code, you have "ownership" of it and you end up doing a much better
> job than if it is anonymous or just hidden within a larger company.  And
> that's a good thing for both the developer, and the overall project.
> 

For a maintainer...yeah.  But when a lawsuit breaks out...that technical
problem quickly takes a back seat.

Now, for something important, when are we going to get Cherries from the
Northwest to NYC?


> greg k-h

Re: Kernel contributions from organisations and individual privacy

[Ruben Safir]

On Thu, Jun 11, 2015 at 10:57:00AM -0700, Greg KH wrote:
> On Thu, Jun 11, 2015 at 12:39:47PM -0400, Ruben Safir wrote:
> > > The only thing you have to agree with when contributing Linux kernel
> > > code is the DCO, which can be found in the file
> > > Documentation/SubmittingPatches, or here online:
> > >   http://developercertificate.org/
> > > 
> > 
> > I didn't know that and looking at it, that is pretty flimsy.
> 
> Not at all, in fact, it's very strong.  A number of other projects also
> use this same document (SAMBA, Docker, etc.), so it is well known and
> proven to work.
> 
> > It is a good thing that up until know this hasn't bit them in the ass
> > so far.  I might be all that is possible though because a CLA, to be
> > really blanket, would require one having to go back to every
> > contribution to date.
> 
> That's only if you wanted to do something crazy like relicense the work.
> And even then, a CLA doesn't help you out, see all of the projects that
> have undertaken this task and what they have done to enable it.  A CLA
> doesn't do much there.
> 

Not at all.  You have a good point there are definitely legal situations
other than relicensing which are problematic.

Lets say Apple decides that are going to take the Linux Kernel and
alter it extensively, in order for it to work with a new hardware platform 
that they created. And lets say don't return the code base to the public.  
Now who is going to protect the license and sue them?  You have literaly 
thousands of partiticpants who have standing now in this case.  Apple can just
blow there nose at you if they are willing to put up with the bad publicity.

anyway...

http://www.h-online.com/open/features/Copyright-assignment-Once-bitten-twice-shy-1049631.html

and I'm finished with this commentary.

Broadly I agree with you and the CLA discussion is a side track.

> greg k-h
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com 

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive 
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com 

Being so tracked is for FARM ANIMALS and and extermination camps, 
but incompatible with living as a free human being. -RI Safir 2013


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel contributions from organisations and individual privacy

[Ruben Safir]

On 06/11/2015 07:37 PM, Rik van Riel wrote:
> On 06/11/2015 07:26 PM, Ruben Safir wrote:
> 
>> Not at all.  You have a good point there are definitely legal situations
>> other than relicensing which are problematic.
>>
>> Lets say Apple decides that are going to take the Linux Kernel and
>> alter it extensively, in order for it to work with a new hardware platform 
>> that they created. And lets say don't return the code base to the public.  
>> Now who is going to protect the license and sue them?  You have literaly 
>> thousands of partiticpants who have standing now in this case.
> 
> That means a thousand possible plaintiffs.
> 
> s/Apple/VMware/ and you get this:
> 
> http://sfconservancy.org/news/2015/mar/05/vmware-lawsuit/
> 
> A number of GPL enforcement projects involving the Linux kernel
> have resulted in GPL compliance already.
> 

yeah, I've been following this case...it is an interesting case but not
exacly on point.  First of all the case is in Germany and their rules of
standing are different.

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel contributions from organisations and individual privacy

[Ruben Safir]

On 06/11/2015 11:31 PM, valdis.kletni...@vt.edu wrote:
> They can't just blow their nose at actual lawsuits.


those lawsuites would be challenged for law of standing.

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel contributions from organisations and individual privacy

[Ruben Safir]

On 06/13/2015 11:40 AM, Bjørn Mork wrote:
> Why do companies still risk this?  For little or no gain whatsoever?  Or
> even negative gain, since we all know that you get many times back for
> every contribution you make to open source.


they just don't want to give back to the community.

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Global variables

[Ruben Safir]

On 06/14/2015 07:28 AM, roni wrote:
> I know i should avoid using global variables in kernel programming.
> 
> What problem it create if i use more global variables?
> 
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 
> 


you step on everyone else's names space.  Do you know how many other
people are collaborating with the kernel.  Stick to your own back yard.

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Global variables

[Ruben Safir]

On 06/14/2015 07:58 AM, AYAN KUMAR HALDER wrote:
> Besides, it hampers reentrancy, unless you use locks(mutex) with each
> global variable.


This is not necessary a function of globalization of variables, although
it damn sure can be, but... honestly, if he is asking this question, it
is not likely that he yet understands race conditions and critical areas.

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Windows Vs Linux - Whats the "Reality"

[Ruben Safir]

On 08/15/2015 10:06 AM, Sasha Mckinsey wrote:
> Hi, came across this discussion thread so thought should share it get the 
> views of the community. I dont agree with all the points mentioned fully but 
> some of the points do make sense. Here it is : 
> 

what does this have to do with learning Linux Kernel programming?


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Windows Vs Linux - Whats the "Reality"

[Ruben Safir]

On 08/15/2015 02:43 PM, Sasha Mckinsey wrote:
> Question is how much truth does the statement hold...think with an open mind. 
> Not trying to discriminate one against the other. 

Well, the mailing list is for Linux Kernel programming newbies.  Endless
debate on OS wars are better let in comp.os.linux.advocacy et al.


You can throw all the flame bait on this very old topic there and they
never give up arguing about it.


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Safety in Kernel Development

[Ruben Safir]

On 08/18/2015 10:03 AM, Kenneth Adam Miller wrote:
> @leo If kmemleak is not a language based approach, I ardently question the
> completeness of such a verification.


this is not a rational approach

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Safety in Kernel Development

[Ruben Safir]

On 08/18/2015 09:25 AM, Kenneth Adam Miller wrote:
> Ok- so I know that C is the defacto standard for kernel development.


That about sums it up.  did you have some question about kernel
development.  This is a mailing list on mentoring and skills
developments in writing the Linux Kernel.  We know it is written mostly
in C.  YOU KNOW it is written in C.  So after this, nothing else you
wrote is relevant to THIS mailing list.

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Safety in Kernel Development

[Ruben Safir]

On 08/18/2015 08:30 PM, Kenneth Adam Miller wrote:
> My interest is clearly on approaches that can be taken to do hardened
> kernel module development.


OK - so that is not this list.  This is a list for newbies mentoring and
linux kernel development.  The only people here that would have any
influence on that are here for mentoring purposes only, and not to be
pitched your ideas for an overhaul of kernel development.

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Safety in Kernel Development

[Ruben Safir]

On 08/18/2015 08:30 PM, Kenneth Adam Miller wrote:
> | "this is not a rational approach"
> 
> I'm very strongly confident the approach of achieving stronger guarantees


Off topic

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Eudyptula task 2

[Ruben Safir]

On 09/08/2015 10:08 PM, Yacdaniel Hurtado García wrote:
> Hi, i am doing task 2 of eudyptula, i cloned the repository, build,
> install and boot the kernel, when i send my response to little i
> attach the uname -a output and the .config but he answers this:
> Linus's tree is newer than this, or you forgot to set the requested
> configuration option :(
> atm i get this kernel version: 4.2.0-rc8 i dont know if i am doing
> something wrong.Thanks
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 
> 


that topic is not allowed on the list ;)

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Translating physical/linear address to virtual address

[Ruben Safir]

On 10/03/2015 12:04 AM, Martin Ichilevici de Oliveira wrote:
> My goal is to use this data to make informed decisions on pages
> distribution in NUMA machines (with libnuma). The problem is that, as
> far as I understood, physical and linear addresses won't necessarily be
> the same between runs of the same program. Virtual addresses, on the
> other hand, can be made to be consistent (by turning address space layout
> randomization off).
> 
> Using virtual addresses also have the advantage that I can do all memory
> management in userspace, with libnuma.


Your not really understanding some basic architectural problems.  Memory
is shifted from segment to segment, the OS has paging, the hardware
hides memory addressing as well, and then there is DME.  How the
motherboard chips lays out and allows access to memory segments is not
something that can be manually controlled, even by the OS because it is
firmware driven.

I'm not saying that what you are doing is impossible, but it doesn't
sound like you approach is likely to work.


http://www.nylxs.com/docs/grad_school/arch/memory.pdf

http://www.nylxs.com/docs/grad_school/arch/

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Does the Community use Coverity ?

[Ruben Safir]

In 2006, the Coverity Scan service was initiated with the U.S. Department of 
Homeland Security 


leaves a warm and fuzzy feeling



On Tue, Dec 15, 2015 at 07:02:42PM +, Jeff Haran wrote:
> >-Original Message-
> >From: kernelnewbies-bounces+jharan=bytemobile@kernelnewbies.org
> >[mailto:kernelnewbies-
> >bounces+jharan=bytemobile@kernelnewbies.org] On Behalf Of
> >pavi1729
> >Sent: Monday, December 14, 2015 11:03 PM
> >To: kernelnewbies@kernelnewbies.org; linux-fsde...@vger.kernel.org; linux-
> >m...@vger.kernel.org; linux-net...@vger.kernel.org
> >Subject: Does the Community use Coverity ?
> >
> >Hi,
> >  May I know if the community uses the Coverity tool and, if yes where can I
> >find a repo of Coverity scans of kernels and IGNORE LIST; cause there
> >obviously would be false positives.
> >
> >Cheers,
> >Pavi
> 
> https://scan.coverity.com/
> 
> Sign up for an account and join the Linux project.
> 
> Jeff Haran
> 
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com 

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive 
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com 

Being so tracked is for FARM ANIMALS and and extermination camps, 
but incompatible with living as a free human being. -RI Safir 2013


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Developing environments used for kernel development

[Ruben Safir]

EMACs might work better if they took LISP out of it and adopted it for a 
QWERTY keyboard

Not that we should have an VI EMAC war.

Ruben


On Thu, Dec 24, 2015 at 02:59:13PM +0300, Andrey Skvortsov wrote:
> On 22 Dec, Daniel. wrote:
> > I was thinking about back to vim, it starts so fast and has everything you
> > need in tree letters, and the completion works out of box.
> If you are bothered by slow start of emacs, you can look at emacsdaemon.
> You start emacs only once, afterwards just connect to started emacs
> session.
> 
> > I never get the
> > completion really working with emacs. I remember that was coding with Lua
> > headers and the completion crashed :( I just give up on it, who needs auto
> > completion..
> > 
> > I'll give vim a second chance :)
> > 
> > Regards
> > Em 22/12/2015 20:15, "Clemens Gruber" 
> > escreveu:
> > 
> > > Hi Daniel,
> > >
> > > > My boss came to my desk today raiging that I should use more productive
> > > > tools for developing. Well I don't want to begin an editor war but, yes,
> > > I
> > > > use emacs. I used to use vim before but the integration of emacs and gdb
> > > > has caught my attention.
> > >
> > > emacs and vim are both very powerful editors, each with their own pros
> > > and cons, but both very suitable for developing code!
> > > I don't think it's a good idea for a boss to force his devs into using
> > > some GUI IDE like Eclipse.
> > > Personally, I don't like it because it is slow (Hi Java!) and does too 
> > > much
> > > stuff which I do not need when writing and debugging non-Java code.
> > >
> > > If you are already used to Emacs and gdb mode, that's great.
> > >
> > > Recently I am more and more using (g)vim and discovered a nice vim plugin:
> > > NERDTree https://github.com/scrooloose/nerdtree (A tree explorer plugin)
> > >
> > > Oh and there is also cgdb: https://github.com/cgdb/cgdb
> > >
> > > Cheers,
> > > Clemens
> > >
> 
> > ___
> > Kernelnewbies mailing list
> > Kernelnewbies@kernelnewbies.org
> > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 
> 
> -- 
> Best regards,
> Andrey Skvortsov
> 
> Secure eMail with gnupg: See http://www.gnupg.org/
> PGP Key ID: 0x57A3AEAD



> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies


-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com 

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive 
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com 

Being so tracked is for FARM ANIMALS and and extermination camps, 
but incompatible with living as a free human being. -RI Safir 2013


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Developing environments used for kernel development

[Ruben Safir]

On 12/24/2015 01:43 PM, valdis.kletni...@vt.edu wrote:
> The only *real* fix is to go to a non-querty keyboard. 


No, retraining and reprogramming the user is not a solution.



-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Developing environments used for kernel development

[Ruben Safir]

On 12/24/2015 07:52 PM, valdis.kletni...@vt.edu wrote:
> On Thu, 24 Dec 2015 19:29:11 -0500, Ruben Safir said:
>> On 12/24/2015 01:43 PM, valdis.kletni...@vt.edu wrote:
>>> The only *real* fix is to go to a non-querty keyboard.
>>
>> No, retraining and reprogramming the user is not a solution.
> 
> Then you're stuck with a control key where it's difficult for
> the left pinky to get to.
> 

As a practicle matter, if you wanted to use EMACs

caps lock is turned off all my system.  But that is just the beginning
of the problem.  EMACS is really designed fro a DVORK keyboard.


> Feel free to suggest remappings that are easy for an index or second finger to
> reach on a querty keyboard (and which don't grab a commonly used key like 'h'
> or '6' :), or some other *real* fix that isn't a partial hack and doesn't fall
> into your "retraining and reprogramming" category.
> 
> 
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 


-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: eudyptula challenge, stuck at task 06 - no reply for four weeks

[Ruben Safir]

On 12/31/2015 01:04 PM, Geyslan G. Bem wrote:
> I was booted too. And I didn't accept that judgement indeed. The rules
> in the site are:


really, that is a rough like you have.


-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: mkinitcpio

[Ruben Safir]

On 02/09/2016 12:16 AM, m...@tobin.cc wrote:
> I am glad this is the newbies list ;)
> 
> The initial problem was 
> 
> # mkinitcpio -g initramfs-custom.img -k 4.5.0-eudyptula+
> ==> Starting build: 4.5.0-eudyptula+
>   -> Running build hook: [base]
>   -> Running build hook: [udev]
>   -> Running build hook: [autodetect]
>   -> Running build hook: [modconf]
>   -> Running build hook: [block]
>   -> Running build hook: [filesystems]
>   -> Running build hook: [keyboard]
>   -> Running build hook: [fsck]
> ==> WARNING: No modules were added to the image. This is probably not
> what you want.
> ==> Creating gzip-compressed initcpio image: /boot/initramfs-custom.img
> ==> Image generation successful
> #
> 
> The cause of the warning turned out to be that I had built the kernel
> with an 'empty' config file. 
> 
> $ zcat /proc/config > config
> 
> instead of
> 
> $ zcat /proc/config > .config
>  
> (note the dot on config)
> 
> If I was more experienced I would have realised this when the compile
> time was so short. It was only  while replying to Pablo with the steps I
> had taken to build the kernel that I noticed my error.
> 
> So, thank you to the kernelnewbies mailing list.
> 
> Regards,
> Tobin Harding
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 


You are not supposed to send the Challenge to the list.  It says that
like 20 times when you sign up to the list :(


-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: mkinitcpio

[Ruben Safir]

On 02/09/2016 01:07 AM, m...@tobin.cc wrote:
> 
> I'm sorry if I have offended you, I don't believe that my question or
> explanation had anything to do with the challenge. Excepting that the
> work eudyptula was in the email
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 


you were asked if this is from the challenge and you said yes.  Are you
trolling us or did I miss understand something?


-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Distributed Process Scheduling Algorithm

[Ruben Safir]

On Thu, Feb 18, 2016 at 09:06:05PM -0800, Greg KH wrote:
> On Thu, Feb 18, 2016 at 10:05:40AM +0530, Nitin Varyani wrote:
> > @ Greg: Since I am very new to the field, with the huge task in hand
> > and a short time span of 3 months given for this project,
> 
Are you formally trained froma  university?  I'm just asking because I know
that many core coders don't even have a college background in comp sci.  
So I'm just curious as to the path you took.

Reuvain


> 3 months?  That's way too short, this is a multi-year/decade type
> research project.  You can barely write a "simple" kernel driver in 3
> months start to finish unless you _really_ know what you are doing.
> 
> I suggest get a new professor / advisor, this one doesn't seem to
> realize the scope of the work involved :)
> 
> good luck!
> 
> greg k-h
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com 

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive 
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com 

Being so tracked is for FARM ANIMALS and and extermination camps, 
but incompatible with living as a free human being. -RI Safir 2013


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

can't read this

[Ruben Safir]

ASCII?


--===3901919624009551412==
Content-Type: multipart/alternative;
boundary="=_Part_49324_945639701.1456072194657"

--=_Part_49324_945639701.1456072194657
Content-Type: text/plain; charset=GBK
Content-Transfer-Encoding: base64

SGksCiAgV2hlbiAgcmVhZCB0aGUgc291cmNlIGNvZGUgb2YgbW1fdHlwZXMuaCwgaSBlbmNvdW50
ZXIgX2NvZGluZyBzdHlsZV8gY29kZSAsc3VjaCBsaWtlOgpodHRwOi8vbHhyLmZyZWUtZWxlY3Ry
b25zLmNvbS9zb3VyY2UvaW5jbHVkZS9saW51eC9tbV90eXBlcy5oI0wzNDYgaW4gY29tbWVudHMu
CldoeSBub3QgdHJ5IHRvIGZpeCBpdD8gQmVjYXVzZSBpdCBpcyB0cml2YWw/IApBY3R1YWxseSwg
Y2hlY2twYXRjaC5wbCByZXBvcnRzIG1hbnkgZXJyb3JzIGFuZCB3YXJubmluZ3MgZm9yIGl0LgpP
bmx5IGNhbiBpIGZpeCB0aGUgY29kaW5nIHN0eWxlIGlzc3VlIGluIHN0YWdpbmc/ClNvcnJ5IGZv
ciB0aGUgbm9pc3kuIAoKCgoKLS0KQmVzdCBSZWdhcmRzCg==
--=_Part_49324_945639701.1456072194657
Content-Type: text/html; charset=GBK
Content-Transfer-Encoding: base64

PGRpdiBzdHlsZT0ibGluZS1oZWlnaHQ6MS43O2NvbG9yOiMwMDAwMDA7Zm9udC1zaXplOjE0cHg7
Zm9udC1mYW1pbHk6QXJpYWwiPjxkaXY+SGksPC9kaXY+PGRpdj4mbmJzcDsgV2hlbiAmbmJzcDty
ZWFkIHRoZSBzb3VyY2UgY29kZSBvZiBtbV90eXBlcy5oLCBpIGVuY291bnRlciBfY29kaW5nIHN0
eWxlXyBjb2RlICxzdWNoIGxpa2U6PC9kaXY+PGRpdj48YSBocmVmPSJodHRwOi8vbHhyLmZyZWUt
ZWxlY3Ryb25zLmNvbS9zb3VyY2UvaW5jbHVkZS9saW51eC9tbV90eXBlcy5oI0wzNDYiIF9zcmM9
Imh0dHA6Ly9seHIuZnJlZS1lbGVjdHJvbnMuY29tL3NvdXJjZS9pbmNsdWRlL2xpbnV4L21tX3R5
cGVzLmgjTDM0NiIgc3R5bGU9ImxpbmUtaGVpZ2h0OiAxLjc7Ij5odHRwOi8vbHhyLmZyZWUtZWxl
Y3Ryb25zLmNvbS9zb3VyY2UvaW5jbHVkZS9saW51eC9tbV90eXBlcy5oI0wzNDY8L2E+Jm5ic3A7
aW4gY29tbWVudHMuPC9kaXY+PGRpdj5XaHkgbm90IHRyeSB0byBmaXggaXQ/IEJlY2F1c2UgaXQg
aXMgdHJpdmFsPyZuYnNwOzwvZGl2PjxkaXY+QWN0dWFsbHksIGNoZWNrcGF0Y2gucGwgcmVwb3J0
cyBtYW55IGVycm9ycyBhbmQgd2Fybm5pbmdzIGZvciBpdC48L2Rpdj48ZGl2Pk9ubHkgY2FuIGkg
Zml4IHRoZSBjb2Rpbmcgc3R5bGUgaXNzdWUgaW4gc3RhZ2luZz88L2Rpdj48ZGl2PlNvcnJ5IGZv
ciB0aGUgbm9pc3kuJm5ic3A7PC9kaXY+PGRpdj48YnI+PC9kaXY+PGRpdj48YnI+PC9kaXY+PGRp
diBzdHlsZT0icG9zaXRpb246cmVsYXRpdmU7em9vbToxIj4tLTxicj5CZXN0IFJlZ2FyZHM8YnI+
PGRpdiBzdHlsZT0iY2xlYXI6Ym90aCI+PC9kaXY+PC9kaXY+PC9kaXY+
--=_Part_49324_945639701.1456072194657--



--===3901919624009551412==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

--===3901919624009551412==--
-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: user rsyslog/syslog

[Ruben Safir]

On 02/24/2016 02:36 AM, Ran Shalit wrote:
> Hello,

systemd?

> 
> I am trying to write to rsyslog from application.
> With openlog(..., LOG_USER), it works fine and I find the log in
> /var/log/user.log (it is defines in /etc/rsyslog.d/50-defaults.conf )
> But we need to enable different applications to have each its own log file.
> I tried to use LOG_LOCAL0 instead and configured it in
> /etc/rsyslog.d/50-defaults.conf the same way as user:
> 
> local0.* action
> {
>   type="omfile"
>  FILE="/var/log/local0.log"
>  FileOwner="root"
>  FileGroup="adm"
> 
> }
> 
> I then did
> 1. /etc/init.d/rsyslog stop
> 2. /etc/init.d/rsyslog start
> I see no warnings or errors, and I started the application trying to
> write to LOG_LOCAL0, But there is no new file created, no logs.
> 
> Is there any idea whatws wrong, or how I can achieve this multi user's logs ?
> 
> Thank you,
> Ran
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 


-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Project Idea..

[Ruben Safir]

On 03/01/2016 10:07 AM, SUNITA wrote:
> I located the following implementations on lwn.net  for finding the
> energy consumption pattern
> 
> http://lwn.net/Articles/603504/
> http://lwn.net/Articles/597279/
> http://lwn.net/Articles/558234/
> http://lwn.net/Articles/557822/
> 
> Are there any more articles which i have missed.
> 

what kind of question is that?


this is a mailing list in kernel internals for newbies.  This is not
hand holding for HW.  If that is all the articles you found then that is
all you will see.

BTW Greg gave you the answer to your inquire on a silver platter and you
ignored it.


Ruben

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: How to rewrite sbull_request in ldd3 for current kernel?

[Ruben Safir]

On Sun, Mar 20, 2016 at 01:58:47PM +0800, 张云 wrote:
> Thanks!
> I have another question if it is possible to rewrite the data transfer 
> function avoiding the bio complexity? 


what is the bio complexity that you are refering to?

> 
> Yun Zhang(张云)
> 
> > On Mar 20, 2016, at 8:13 AM, Dongli Zhang  
> > wrote:
> > 
> > Please refer to 
> > https://github.com/21cnbao/training/tree/50506cf04bc5616e0c3f3285dbb006c54deb1c53/kernel/drivers/vmem_disk
> > 
> > Dongli Zhang (张东立)
> > http://finallyjustice.github.io
> > 
> > 
> > 
> >> From: zyun...@163.com 
> >> Subject: How to rewrite sbull_request in ldd3 for current kernel? 
> >> Date: Sat, 19 Mar 2016 21:22:19 +0800 
> >> To: kernelnewbies@kernelnewbies.org 
> >> 
> >> Hi, 
> >> I am reading the book, Linux Driver Development 3. 
> >> In the chapter on block driver of this book, I need some help to 
> >> rewriting the sbull_request since the kernel’s block API was changed. 
> >> 
> >> The sbull_request code: 
> >> /* 
> >> * The simple form of the request function. 
> >> */ 
> >> static void sbull_request(request_queue_t *q) 
> >> { 
> >> struct request *req; 
> >> 
> >> while ((req = elv_next_request(q)) != NULL) { 
> >> struct sbull_dev *dev = req->rq_disk->private_data; 
> >> if (! blk_fs_request(req)) { 
> >> printk (KERN_NOTICE "Skip non-fs request\n"); 
> >> end_request(req, 0); 
> >> continue; 
> >> } 
> >> sbull_transfer(dev, req->sector, req->current_nr_sectors, 
> >> req->buffer, rq_data_dir(req)); 
> >> end_request(req, 1); 
> >> } 
> >> } 
> >> 
> >> I have rewritten the code above into: 
> >> 
> >> /* 
> >> * The simple form of the request function. 
> >> */ 
> >> void blkplay_request(struct request_queue *q) 
> >> { 
> >> struct request *req; 
> >> 
> >> while (!blk_queue_stopped(q) && 
> >> (req = blk_peek_request(q)) != NULL) { 
> >> struct blkplay_dev *dev = req->rq_disk->private_data; 
> >> blk_start_request(req); 
> >> if (req->cmd_type != REQ_TYPE_FS) { 
> >> printk (KERN_NOTICE "Skip non-fs request\n"); 
> >> blk_end_request(req, -EIO, 0); 
> >> continue; 
> >> } 
> >> 
> >> /* I don’t know how to write the statement below */ 
> >> blkplay_transfer(dev, req->sector, req->current_nr_sectors, 
> >> req->buffer, rq_data_dir(req)); 
> >> 
> >> blk_end_request_cur(req, 0); 
> >> } 
> >> } 
> >> 
> >> 
> >> Is the rewrite proper? 
> >> 
> >> 
> >> 
> >> The compiler can’t compile it because the request struct no longer has 
> >> 
> >> the field of ‘sector’ and ‘current_nr_sectors’. I have read the kernel 
> >> code 
> >> 
> >> about the request struct, the kernel code said the __data_len and 
> >> __sector field of 
> >> request struct is internal so that we shouldn’t access them directly. 
> >> 
> >> How could I rewrite it ? Thanks. 
> >> 
> >> ___ Kernelnewbies mailing 
> >> list Kernelnewbies@kernelnewbies.org 
> >> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies 
> >   
> > ___
> > Kernelnewbies mailing list
> > Kernelnewbies@kernelnewbies.org
> > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 
> 
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com 

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive 
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com 

Being so tracked is for FARM ANIMALS and and extermination camps, 
but incompatible with living as a free human being. -RI Safir 2013


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Linux Kernel Group Scheduling Feature of CFS

[Ruben Safir]

On 03/21/2016 12:42 PM, SUNITA wrote:
> Hello,
> I want to test the properties of CFS scheduler on a beaglebone.
> 

This is extremely documented and a subject of nearly every graduate
school and undergrad OS class and thesis.  I don't think your
understanding how it works and I suggest you research this FIRST and
reviewing the source code PRIOR to coming to the mailing list and
begging for help.

Also, make sure you search usenet archives.

Then if you have a specific question, you can frame a good question.

Good luck

Reuvain Safir



-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Please, add me to EditorsGroup

[Ruben Safir]

do they know you that you want editing privledges?


On Tue, Aug 16, 2016 at 01:11:59PM +0300, Aleksander Alekseev wrote:
> Hello.
> 
> I would like to contribute to kernelnewbies.org. In particular today I
> discovered that link to oftc.net on IRC page is broken and I would like
> to fix this.
> 
> My account: AleksanderAlekseev
> 
> -- 
> Best regards,
> Aleksander Alekseev
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com 

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive 
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com 

Being so tracked is for FARM ANIMALS and and extermination camps, 
but incompatible with living as a free human being. -RI Safir 2013


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Q: dma requires copying into dma buffer - so what's the benefit ?

[Ruben Safir]

On 09/06/2016 12:24 PM, Ran Shalit wrote:
> Hello,
> 
> There is something I don't understand about dma,
> when doing memory to memory dma, it requires to cllocate dma buffer
> (for example with dma_alloc_coherent),
> than for each transfer we need to copy the buffer to the allocated
> memory and than trigger dma transaction.
> So, if it requires additional memcpy for each transaction , what's the
> benefit of using dma ?
> 
> without dma:
> 1. copy buffer (memcpy) from source to destination
> 
> with dma:
> 1. copy buffer (memcpy) from source to dma buffer
> 2. trigger dma transaction (which shall copy the buffer eventually to
> destination buffer)

DMA hardware uses an expedited bus that frees the main memory to be
addressed for other processes.

> 
> Regards,
> Ran
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 


-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Request Chinese mail list and FrontPage

[Ruben Safir]

On 09/06/2016 12:47 AM, Hao Lee wrote:
> On Tue, Sep 6, 2016 at 10:54 AM, Adam Lee  wrote:
>>
>> Actually we have one: ker...@vger.linux-kernel.cn, but it has extremely
>> low activity.
>>

Isn't it easier for the Chinese to learn English.  The source is in
romantic chars.

>> I suggest you ask and answer in this kernelnewbies mail list. People are
>> nice here, simple/basic English is not a problem.
>>
> 
> Hi, Adam Lee
> 
> Thanks for your reply. I've searched this email address for details.
> It seems that the domain linux-kernel.cn has been invalid and I
> couldn't access www.linux-kernel.cn. Is the mailing list still in use?
> 
> Thanks,
> Hao Lee
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 


-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: patch against linux-next

[Ruben Safir]

On 11/21/2016 08:48 PM, Amit Kumar wrote:
> Hi,
> 
> As far as I know that linux-next tree is a preview of patches which will be
> merged in the mainline kernel. I've noticed that recently linux-next is
> updated with a gap. Can a patch be created against linux-next tree?
> 
> 
> 
> A kernel newbie,
> Amit Kumar
> 
>

why ask that here?

> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 


-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: patch against linux-next

[Ruben Safir]

On 11/21/2016 11:28 PM, Amit Kumar wrote:
> On Tue, Nov 22, 2016, 8:41 AM Ruben Safir  wrote:
> 
>> On 11/21/2016 08:48 PM, Amit Kumar wrote:
>>> Hi,
>>>
>>> As far as I know that linux-next tree is a preview of patches which will
>> be
>>>

This is an academic area, and has nothing to do with actual kernel
development.  You must know that.  Shoot an email off to li...@linux.com



 merged in the mainline kernel. I've noticed that recently linux-next is
>>> updated with a gap. Can a patch be created against linux-next tree?
>>>
>>>
>>>
>>> A kernel newbie,
>>> Amit Kumar
>>>
>>>
>>
>> why ask that here?
>>
> Because I'm a kernel newbie and I want to submit patches on lkml.
> 
>>
>>>
>>> ___
>>> Kernelnewbies mailing list
>>> Kernelnewbies@kernelnewbies.org
>>> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>>>
>>
>>
>> --
>> So many immigrant groups have swept through our town
>> that Brooklyn, like Atlantis, reaches mythological
>> proportions in the mind of the world - RI Safir 1998
>> http://www.mrbrklyn.com
>>
>> DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
>> http://www.nylxs.com - Leadership Development in Free Software
>> http://www2.mrbrklyn.com/resources - Unpublished Archive
>> http://www.coinhangout.com - coins!
>> http://www.brooklyn-living.com
>>
>> Being so tracked is for FARM ANIMALS and and extermination camps,
>> but incompatible with living as a free human being. -RI Safir 2013
>>
>> ___
>> Kernelnewbies mailing list
>> Kernelnewbies@kernelnewbies.org
>> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>>
> 


-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: &array[0] vs array

[Ruben Safir]

On 03/29/2017 08:30 PM, Tobin C. Harding wrote:
> Does the kernel community have a preference when using the address of
> the first element of an an array?
> 
> 1. addr = &array[0]
> 2. addr = array;
> 
> $ grep '\&.*\[0\]' | wc -l
> 10077
> 
> style (1) is clearly used, I was not able to grep for instances where
> style (2) is used.

maybe there is a another reason why 2 is not used.

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Eudyptula Challenge scripts not responding?

[Ruben Safir]

On 07/06/2017 09:30 AM, Alexander Kapshuk wrote:
> The response times vary between hearing from them the same day to up
> to a few weeks.
> 
> They will get back to you eventually.

not always ;)

Sometimes it takes a nudge


-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: OOM killer hung the whole system

[Ruben Safir]

On 07/30/2017 03:51 PM, Mulyadi Santosa wrote:
> ust malloc() without free().


and that surprises you?

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Don't know where to start linux kernel programming

[Ruben Safir]

On 08/22/2017 07:26 PM, Greg Freemyer wrote:
> just send an email to the right address and all the
> participants in the thread will do a reply-all so you can see the
> responses without subscribing.??

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Don't know where to start linux kernel programming

[Ruben Safir]

On 08/22/2017 01:39 PM, Greg KH wrote:
> On Tue, Aug 22, 2017 at 12:59:31PM -0400, valdis.kletni...@vt.edu wrote:
>> On Tue, 22 Aug 2017 12:48:42 -0400, Cindy-Sue Causey said:
>>
>>> An observation that may just mean I haven't stumbled upon it yet is
>>> that it would be nice to... stumble upon... a list of kernel problems
>>> that *kernelnewbies* could cut their teeth on. I do understand that
>>> this is a naive wish list item due to the nearly every nanosecond
>>> changing complexity of things. :)
>>
>> Such a thing existed 10 or 15 years ago.  Unfortunately for the newbies, 
>> there
>> are very few problems that newbies can attack, because if they were that
>> simple, somebody would already have *done* them.
> 
> Not really, please look at drivers/staging/*/TODO there are loads of
> simple things left to do, with more being added all the time (a huge new
> wireless driver just landed that could use lots of cleanups.)
> 
>> One thing in particular that pretty much killed the kernel-janitors project
>> (which did cleanup of code) was a change in the rules for kernel API changes.
>> Before, somebody could add a new/changed API, and the janitors would change 
>> all
>> the uses in the tree.  We now require that a patch series that changes an API
>> has to also fix all in-tree uses of the API.
> 
> That's always been the rule, you could never break the build.  What is
> better now in that people who do the new API usually fix everything up
> at the same time because they want to drop the old API sooner rather
> than later.
> 
> thanks,
> 
> greg k-h
> 

You need the hardware though?

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Don't know where to start linux kernel programming

[Ruben Safir]

On 08/23/2017 07:46 PM, Greg Freemyer wrote:
> Rubin, did you add the ??
> 

yes, somewhere it got reformated.


> If so, that's how it works.  The linux-kernel mailing lists are not
> closed.  Anyone can post an email to the list address, if it passes
> the spam filter it will get forwarded to the subscribers.
> 
> The subscribers will do a reply-all and your thread is off to the
> races without you subscribing.
> 
> Or let's say there is an ongoing thread on the SATA kernel mailing
> list and they need to bring in a core developer that isn't subscribed
> for some reason.
> 
> They can just add him or her to the TO: line and going forward they
> should be kept in the loop for that thread.

Your not adding another list, your just adding a separate user.  I
usually add it to CC.  What we do not do, normally, is allow a
non-describer to post to a list, nor cross posting.  That is chaos at
best, and a relay hole for spam and worst.

> 
> It's a nice model for managing a large number of specialists mailing
> lists.  No one wants to subscribe to all of them, but from time to
> time people need to interact with the people on one of the specialist
> email lists and don't want to have to
> subscribe->participate->unsubscribe.
> 
> Greg


-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Don't know where to start linux kernel programming

[Ruben Safir]

On 08/23/2017 08:46 PM, Greg KH wrote:
> On Wed, Aug 23, 2017 at 08:03:43PM -0400, Ruben Safir wrote:
>>> They can just add him or her to the TO: line and going forward they
>>> should be kept in the loop for that thread.
>>
>> Your not adding another list, your just adding a separate user.  I
>> usually add it to CC.  What we do not do, normally, is allow a
>> non-describer to post to a list, nor cross posting.  That is chaos at
>> best, and a relay hole for spam and worst.
> 
> Not true, that is how the kernel mailing lists at vger.kernel.org work,
> anyone can post to them, you do not have to be subscribed at all.
> 
> The spam filtering on them is great, and really quite easy, just
> disallow html email and almost all of it goes away :)
> 

I wish that was still true but it takes quite a bit more these days :(

> greg k-h
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 


-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Numa node 0 is missing from /sys/devices/system/node , only Numa node 1 is shown

[Ruben Safir]

On 09/07/2017 03:32 PM, Kevin Wilson wrote:
> Hi,
> 
> I have Ubuntu 14.04.5 LTS on x86_64 machine. I am using the
> kernel as shipped with the distro, no modification whatsoever.
> After fresh reboot I do see Numa node 1 but there is no Numa node 0 under:
> 
>  /sys/devices/system/node
> 
https://www.kernel.org/doc/ols/2004/ols2004v1-pages-89-102.pdf


> 
> What can be the reason for this ? lscpu shows two sockets but only one
> NUMA node:
> 
> lscpu
> Architecture:  x86_64
> CPU op-mode(s):32-bit, 64-bit
> Byte Order:Little Endian
> CPU(s):16
> On-line CPU(s) list:   0-15
> Thread(s) per core:2
> Core(s) per socket:4
> Socket(s): 2
> NUMA node(s):  1
> ...
> 
> 
> and
> cat /boot/config-4.4.0-31-generic | grep CONFIG_NUMA
> shows:
> CONFIG_NUMA_BALANCING=y
> CONFIG_NUMA_BALANCING_DEFAULT_ENABLED=y
> CONFIG_NUMA=y
> # CONFIG_NUMA_EMU is not set
> 
> Also
> dmesg | grep  -i numa
> [0.00] NUMA: Initialized distance table, cnt=2
> [0.00] NUMA: Node 1 [mem 0x-0xbfff] + [mem
> 0x1-0x33fff] -> [mem 0x-0x33fff]
> 
> 
> Any ideas ?
> Regards,
> Kevin
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 


-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Swap causing huge latency on disk IO operations

[Ruben Safir]

On 09/10/2017 01:02 AM, Greg KH wrote:
> That's your problem, 2.6.32 is _very_ old and obsolete.  No one in the
> community can help you out with that release anymore, sorry.

that is true, but swapping at times is still a huge problem.  I tend to
just turn it off.

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Swap causing huge latency on disk IO operations

[Ruben Safir]

On 09/10/2017 01:56 AM, Sudharsan Vijayaraghavan wrote:
> 
> My general question is that has the community seen "swap latency issues
> with disk IO" in general. Further can we assume that later kernels (like
> 4.4) does not exhibit such a behavior.

the problems with swap is not limited to any specific OS, and in fact,
Linux does it fairly well.

You're dealing with a Hardware device which is suseptable to numerous
troubles,


-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Why replacing running executable file is forbidden, but overwriting of memory mapped shared object is allowed ?

[Ruben Safir]

On 11/10/2017 12:49 PM, Jeffrey Walton wrote:
> Microsoft technology 

That is an oxymoron

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Regarding Linux kernel vs Android

[Ruben Safir]

I doesn't matter that much when you can't root the devices...


On Tue, Jan 16, 2018 at 05:52:38PM +0100, Greg KH wrote:
> On Tue, Jan 16, 2018 at 10:15:39PM +0530, inventsekar wrote:
> > Hi...
> > 
> > I tried searching but no luck.
> > Can you please suggest how Linux kernel was modified and became Android?!
> 
> It did not.
> 
> Android devices use the Linux kernel, with only a very tiny set of
> patches on top of it, just like any other embedded Linux device.  You
> can see the latest Android kernel trees on the Android Open Source
> project site, just search for them.
> 
> hope this helps,
> 
> greg k-h
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com 

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive 
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com 

Being so tracked is for FARM ANIMALS and and extermination camps, 
but incompatible with living as a free human being. -RI Safir 2013


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Linux Kernel contains only C code?

[Ruben Safir]

On 01/26/2018 02:20 AM, Larry Chen wrote:
> I have never seen c++, perl or python code in kernel source tree.
> Imagine that, if kernel relies on perl, python or other 3rd-party code,
> will it cause nested or mutual dependency issues? 3rd-party code bugs
> may also cause problems that make the kernel unstable.


Its not even really C, at least not as a normal application developer
thinks of it.  This is systems programming with a lot of kernel specific
libraries.

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: clang warning: implicit conversion in intel_ddi.c:1481

[Ruben Safir]

> 
> What is the goal of these types of emails?
> 

even more so on this mailing list.  It almost feels like guerilla
advertising for Clang.


> thanks,
> 
> greg k-h
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com 

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive 
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com 

Being so tracked is for FARM ANIMALS and and extermination camps, 
but incompatible with living as a free human being. -RI Safir 2013


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: clang warning: implicit conversion in intel_ddi.c:1481

[Ruben Safir]

> 
> We are interested 


who is we?


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: newbie

[Ruben Safir]

use mutt


On Fri, Feb 09, 2018 at 11:01:52PM +0530, yash omer wrote:
> Hello,
> Please guide me how to follow with mailing list

> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies


-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com 

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive 
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com 

Being so tracked is for FARM ANIMALS and and extermination camps, 
ut incompatible with living as a free human being. -RI Safir 2013
1

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Year 2038 time set problem

[Ruben Safir]

On 03/04/2018 01:31 PM, valdis.kletni...@vt.edu wrote:
> Note that saying "The CPU isn't vulnerable to Meltdown/Spectre, therefor
> the 4.1 kernel is OK" is *incredibly* wrong.
> 
> For the record, since 4.1 came out, there's been at *least* a dozen security
> issues in the Linux kernel that have been a *lot* scarier for security
> professionals than the Meltdown/Spectre issue.  That only got any news 
> coverage
> because it was an actual hardware design flaw that was believed to be 
> difficult
> to easily fix with software changes...

By this standard, it is necessary to update the kernel and reboot nearly
every week.  Is that right?




-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Year 2038 time set problem

[Ruben Safir]

On 03/04/2018 05:24 PM, valdis.kletni...@vt.edu wrote:
> If you can't afford the disruption of service a reboot causes, you *really*
> need to be deploying HA or load-balancer solutions.
> 
> Because if you can't afford a reboot's worth of 15-20 minutes of downtime, you
> *really* can't afford the 6-8 hours you're probably going to be down if a chip
> soldered onto the motherboard/backplane fries.
> 
> (All of $DAYJOB's important systems are behind HA or load-balancers, as well 
> as
> HA-capable storage.  Let's just say that some vendors make it easier than
> others to set up 8+2 RAID6 across 10 separate shelves of storage, and 
> designing
> mutli-petabyte solutions without single points of failure is harder than it 
> looks :)
> 


These questions always lead into these philosophical discussions as to
how I should run my boxes and theoretical flights of opinionated rubbish
that I am not interested in.  I got the answer to the question I needed
and it is very sobering.

I am not setting up a high availability cluster in my house, thank you.
And fwiw, I've run systems for 6-8 years without rebooting on pc
hardware.  My little fanless fit/pc service running an intel atom had at
one time run 5 years without rebooting.  I only had a system fry once
while it was up an running since the late 1990's until today, and in
that case it was wild power surge and the hardware was up and running in
20 minutes with a swap out of the hard drive.

The linux kernel is integrated into dozens of devices which never see
the light of day for kernel upgrades from PPOE routers, IOT devices,
cellphones, VOIP boxes, electrocardiograms, menu displays for McDonalds,
signal boxes on train systems, etc etc etc.

What has been described is a huge security problem and your solution is
a non-starter and doesn't help the broader problem.



-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Year 2038 time set problem

[Ruben Safir]

On 03/04/2018 09:35 PM, Alex Arvelaez wrote:
> If you don't need high availability, what's the problem with the occasional 
> reboot?

I have a life, and its a chore to reboot the 3 boxes after every
upgrade.  It runs my phones, my TV, my house security, and my mail and
webserver and booting them all is a PIA.  If it is raining security
holes with every kernel upgrade, that is a big problem, and that is
before all these appliances.

Advice?  Who am I to give advice?  On the face of it, I would say they
need to harden the kernel base release.  But I am not qualified to give
anyone advice.  If a kernel can't be reasonably secure in a 2 year
period, as a consumer I can only be unhappy about it and a bit dismayed.
 But no one owes me anything.

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Year 2038 time set problem

[Ruben Safir]

On 03/04/2018 11:07 PM, Alex Arvelaez wrote:
> easy: set up a cronjob to do it for you.

no, it won't work.  It requires supervision

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Year 2038 time set problem

[Ruben Safir]

On 03/04/2018 11:15 PM, valdis.kletni...@vt.edu wrote:
> I repeat what I said - if you can't afford a reboot because it's mission 
> critical,
> you can't afford to *not* be doing HA or load balancing or something.


I know, that is the thing about talking to guys like you.  It is a
personality type.  Its worst that talking to a rock.  You just repeat
the same insane advice over and over.  Complete tunnel vision.  You
don't even have a clue as to how to deal with this problem.  Truthfully,
you don't know what the problem even is.

Don't pretend to understand what I can and can not afford.  Your not
picking security policy for Google.  What your failing to address,
because you are so blinded to your own frame of reference, is that your
solution leaves out well over 90% of the devices connected to the
internet, some of those devices connected to things like nuclear power
plants.  Others are just VOIP appliances.

This conversation is now over, at least for me.  Repeating the same bad
advice is not contributing to anyone, and especially not I.



-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Year 2038 time set problem

[Ruben Safir]

On 03/04/2018 11:15 PM, valdis.kletni...@vt.edu wrote:
>> I only had a system fry once
>> while it was up an running since the late 1990's until today, and in
>> that case it was wild power surge and the hardware was up and running in
>> 20 minutes with a swap out of the hard drive.
> The fact that you've kept a system going for 8 years without a reboot
> isn't proof that actually doing so is a good idea security wise.
> 

I made that point  with regard to the silly notion that somehow the
hardware would just magically fry periodically.  On the scale I'm
working at, hardware failure over decades is rare.


Whether it is reasonable to expect to be able to use a kernel securely
for 8 years is a problem I leave for the experts.

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Year 2038 time set problem

[Ruben Safir]

On 03/04/2018 11:15 PM, valdis.kletni...@vt.edu wrote:
> The big problem *there* isn't that a reboot is often required.

Yes, it is a problem.  If you have 25 thousand signal switches that
depend on, and build a wifi network for signally and telemetry, you
aren't going to be able to put all those devices behind a cluster, and
you sure as hell aren't going to reboot them all every week.  These
things need to be all but bulletproof on installation.  That is the way
that the world works outside of a server farm closet.

... just as an example

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Year 2038 time set problem

[Ruben Safir]

On 03/05/2018 12:53 AM, Greg KH wrote:
>> no, it won't work.  It requires supervision
> Then you are doing it wrong :)


That goes without saying.  I'm always doing things wrong :)
I'm very creative at doing things wrong.

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Year 2038 time set problem

[Ruben Safir]

On 03/05/2018 01:00 AM, Greg KH wrote:
> "How many security issues were those systems
> vulnerable to over that period of time?  All of them."


So I'm understanding.  And yet, the kernel is getting harder and harder
to manage.  It takes hours to just walk through all the choices.

I went from using opensuse to using a rolling release of Artix, which is
arch based.  One of the things I've noticed is that the number of kernel
upgrades are brisk, which with opensuse, it was rare for a kernel
upgrade.  I thought most of these upgrades was updated hardware options
and features, and not security.  Opensuse would get upset if you didn't
use their derivative of the kernel.

With Artix, it really seems that kernels get upgraded weekly

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Year 2038 time set problem

[Ruben Safir]

On 03/05/2018 03:50 AM, valdis.kletni...@vt.edu wrote:
> Give an example of a system - *ANY* system - where you *can't* afford
> the time down for a reboot, but the downtime for a hardware failure *is*
> acceptable.

You are right.  No you move on to another target.. where you can show
you are right

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Year 2038 time set problem

[Ruben Safir]

On 03/05/2018 06:29 AM, Bernd Petrovitsch wrote:
> And why should "we" (whoever that is) fix the problems of others?
> 
> The upstream can't do anything directly if the downstream simply
> refuses to update (if there are fixes to real threats) and/or reboot
> (if it's the kernel).


So any system where you need to, or want to install it and forget about
it for a long period of time, the Linux kernel can not be considered a
choice for that usage because it needs contact oversite and upgrades.

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Year 2038 time set problem

[Ruben Safir]

On 03/05/2018 03:50 AM, valdis.kletni...@vt.edu wrote:
> Give an example of a system - *ANY* system - where you *can't* afford
> the time down for a reboot, but the downtime for a hardware failure *is*
> acceptable.

this is a black hole of a conversation.   I see no benefit to it at this
point.  Your not even reading what I wrote.

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Year 2038 time set problem

[Ruben Safir]

On 03/05/2018 03:50 AM, valdis.kletni...@vt.edu wrote:
> If it's the
> former, then you have to learn that reboots are like changing the oil
> in your car 

yeah, BTW, my car doesn't need its oil changed any longer.  It hasn't
needed to be done before 100,000 miles since the mid-1980s.  I only WISH
that the kernel development used automobile industry standards for
reliability and security.

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com

Being so tracked is for FARM ANIMALS and and extermination camps,
but incompatible with living as a free human being. -RI Safir 2013

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Year 2038 time set problem

[Ruben Safir]

On Mon, Mar 05, 2018 at 07:26:23AM +0100, Greg KH wrote:
> On Mon, Mar 05, 2018 at 01:15:03AM -0500, Ruben Safir wrote:
> > On 03/05/2018 01:00 AM, Greg KH wrote:
> > > "How many security issues were those systems
> > > vulnerable to over that period of time?  All of them."
> > 
> > 
> > So I'm understanding.  And yet, the kernel is getting harder and harder
> > to manage.  It takes hours to just walk through all the choices.
> 
> You're doing it wrong.  Don't ever walk through "all the choices".
> 
> Take a distro kernel, boot your box, plug in all of the devices you want
> to support, then do:
>   'make localmodconfig'


I did a make oldconfig on a virtual system yesterday and it had pages of
choics it considered new.  That was on my laptop, a few years old. :(

> in your own kernel drectory and spend 5 minutes building your new
> kernel and then booting into it.
> 
> > I went from using opensuse to using a rolling release of Artix, which is
> > arch based.  One of the things I've noticed is that the number of kernel
> > upgrades are brisk, which with opensuse, it was rare for a kernel
> > upgrade.  I thought most of these upgrades was updated hardware options
> > and features, and not security.  Opensuse would get upset if you didn't
> > use their derivative of the kernel.
> 
> Then use your distros version of a kernel.  opensuse is great, as is
> arch, and a few other community-based distros, like Fedora.  I trust
> them to get it right with kernel updates.  If you don't want to do it
> yourself, use one of those "big 3" and feel quite comfortable with
> rebooting every few weeks and all will be fine.
> 
> thanks,
> 
> greg k-h
> 
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

-- 
So many immigrant groups have swept through our town
that Brooklyn, like Atlantis, reaches mythological
proportions in the mind of the world - RI Safir 1998
http://www.mrbrklyn.com 

DRM is THEFT - We are the STAKEHOLDERS - RI Safir 2002
http://www.nylxs.com - Leadership Development in Free Software
http://www2.mrbrklyn.com/resources - Unpublished Archive 
http://www.coinhangout.com - coins!
http://www.brooklyn-living.com 

Being so tracked is for FARM ANIMALS and and extermination camps, 
but incompatible with living as a free human being. -RI Safir 2013


___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies