Re: Queries on USB skeleton Driver

2012-12-06 Thread Sannu K
On Fri, Dec 7, 2012 at 9:40 AM, sanchayan maity wrote: > Hello, > > I wanted to use the usb-skeleton driver for transferring data to a pen > drive. I am using Ubuntu 12.04 with kernel version 3.2.0. I remove the > usb-storage driver with rmmod and then inserted the skeleton module. The > module is

Re: Best and fastest way to understand kernel subsystem ?

2012-12-06 Thread sanjeev sharma
Hi, First you need to start with basic of kernel and book for kernel by Robert Love will help you.Both file-system and networking are major subsystem in Kernel and required an knowledge of file-system & networking. Thanks Sanjeev Sharma On Thu, Dec 6, 2012 at 3:24 PM, Shraddha Kamat wrote: >

Queries on USB skeleton Driver

2012-12-06 Thread sanchayan maity
Hello, I wanted to use the usb-skeleton driver for transferring data to a pen drive. I am using Ubuntu 12.04 with kernel version 3.2.0. I remove the usb-storage driver with rmmod and then inserted the skeleton module. The module is inserted successfully. On inserting the drive, usb-storage module

Re: double exclamation mark meaning ?

2012-12-06 Thread devendra.aaru
On Thu, Dec 6, 2012 at 4:50 AM, Shraddha Kamat wrote: > Hi, > > # define likely(x) __builtin_expect(!!(x), 1) > # define unlikely(x)__builtin_expect(!!(x), 0) > > I see these !! in the above expressions. Please explain me the > meaning of those double exclamations. What is their significance

Re: Best and fastest way to understand kernel subsystem ?

2012-12-06 Thread Anuz Pratap Singh Tomar
On Thu, Dec 6, 2012 at 9:54 AM, Shraddha Kamat wrote: > What is the best (and the fastest ) way to understand a kernel > subsystem ( for e.g., filesystem , Networking .. etc.) > There is no fast way to learn Filesystem and Networking subsystems, probably one of the biggest subsystems in kernel. y

RE: transfering pages from user space to user space

2012-12-06 Thread Pablo Pessolani
Hi Yann: Reading the patch source code I find that the pages from one user space to other are "copied" 102 if (vm_write) 103 ret = copy_from_user(target_kaddr, 104 lvec[*lvec_current].iov_base 105

Re: Best and fastest way to understand kernel subsystem ?

2012-12-06 Thread Matthias Brugger
On 12/06/2012 10:54 AM, Shraddha Kamat wrote: > What is the best (and the fastest ) way to understand a kernel > subsystem ( for e.g., filesystem , Networking .. etc.) If you are a beginner it might be convenient to look on a small subsystem first. The filesystem is really big and complicated, I

RE: transfering pages from user space to user space

2012-12-06 Thread Pablo Pessolani
Hi: > This sounds a lot like "Cross Memory Support" (eg CROSS_MEMORY_ATTACH > option) introduced in Linux 3.2: > > http://kernelnewbies.org/Linux_3.2#head-a5e26c6275e85a5c9c41873fbab96bd38d934b72 > > Cross Memory Support add two syscalls: > - process_vm_readv() : read from a process memory >

Re: Best and fastest way to understand kernel subsystem ?

2012-12-06 Thread Abhijit Pawar
On 12/06/2012 05:32 PM, rush wrote: > Hi, > Most of O'Reilly books are pretty old. Afair the latest O'Reilly book is from > Robert Love about 2.6.34. Does it make sense? Yes. Its a good book. > Or even book 2005 are still usefull? Even if the books are older they can give you the general idea abou

Re: Best and fastest way to understand kernel subsystem ?

2012-12-06 Thread rush
Hi,Most of O'Reilly books are pretty old. Afair the latest O'Reilly book is from Robert Love about 2.6.34. Does it make sense?Or even book 2005 are still usefull? -- rush 06.12.2012, 15:49, "Abhijit Pawar" :On 12/06/2012 03:24 PM, Shraddha Kamat wrote: What is the best (and the fastest ) way to und

Re: Best and fastest way to understand kernel subsystem ?

2012-12-06 Thread Abhijit Pawar
On 12/06/2012 03:24 PM, Shraddha Kamat wrote: > What is the best (and the fastest ) way to understand a kernel > subsystem ( for e.g., filesystem , Networking .. etc.) Reading the kernel code is the best way. For reference you can use LDD3 and books from OReilly. > > -- Shraddha > > > ___

Re: double exclamation mark meaning ?

2012-12-06 Thread Prabhakar Lad
Hi, On Thu, Dec 6, 2012 at 3:20 PM, Shraddha Kamat wrote: > Hi, > > # define likely(x) __builtin_expect(!!(x), 1) > # define unlikely(x)__builtin_expect(!!(x), 0) > > I see these !! in the above expressions. Please explain me the > meaning of those double exclamations. What is their signific

Re: double exclamation mark meaning ?

2012-12-06 Thread Yann Droneaud
> Hi, > > # define likely(x) __builtin_expect(!!(x), 1) > # define unlikely(x)__builtin_expect(!!(x), 0) > > I see these !! in the above expressions. Please explain me the > meaning of those double exclamations. What is their significance ? > This is a kind of cast to a "bool". After applyin

Re: transfering pages from user space to user space

2012-12-06 Thread Yann Droneaud
Hi, Le mercredi 05 décembre 2012 à 22:47 -0300, Pablo Pessolani a écrit : > Hi: > I am working on a project to copy (page aligned) the > buffer content of one process to the buffer of other process. > > Now I resolved this issue using copy_page() but, analizing > performance with diff

Best and fastest way to understand kernel subsystem ?

2012-12-06 Thread Shraddha Kamat
What is the best (and the fastest ) way to understand a kernel subsystem ( for e.g., filesystem , Networking .. etc.) -- Shraddha ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnew

double exclamation mark meaning ?

2012-12-06 Thread Shraddha Kamat
Hi, # define likely(x) __builtin_expect(!!(x), 1) # define unlikely(x)__builtin_expect(!!(x), 0) I see these !! in the above expressions. Please explain me the meaning of those double exclamations. What is their significance ? -- Shraddha __