Usually a user process can hang inside kernel if it makes a system call and
is blocked inside kernel waiting on a semaphore (where it would leave CPU)
or spinning for a spinlock which might lock down the CPU core. You can
examine where process is stuck by:
# echo w > /proc/sysrq-trigger
This sysr
Hi All,
A quick question:
If any of user space process is hanged or not responding, does it means
kernel is also hung in some part? I trying to understand why hang happens
and what triggers it.happening ? How to go about recover a hang process,
apart from restarting it.
Regards,
Vipul.
On 2013年12月03日 20:35, 乃宏周 wrote:
> For debugging purpose, I want something like 'getchar()' that can pause
> execution in the module code. Do any candidates I can choose?
>
Create a /proc/knob to turn on or off your code path flow on fly, instead of
using user space getchar.
Otherwise, you sho
On Mit, 2013-12-04 at 23:21 +0200, Daniel Baluta wrote:
> On Tue, Dec 3, 2013 at 4:20 PM, Bernd Petrovitsch
> wrote:
> > On Die, 2013-12-03 at 08:38 -0500, valdis.kletni...@vt.edu wrote:
> >> On Tue, 03 Dec 2013 20:35:41 +0800, said:
> >> > For debugging purpose, I want something like 'getchar()'
On Thu, Dec 5, 2013 at 12:19 PM, Chandan Jay Sharma wrote:
> Sometime back I faced similar error on my CentOS machine and after
> googling I fixed it in 2 steps.
>
> 1. ln -s /usr/src/kernels/*2.6.32-220.**el6.x86_64*
> /lib/modules/2.6.32-220.el6.x86_64/*build*
> 2. ln -s
> /lib/modules/2.6.32-
Sometime back I faced similar error on my CentOS machine and after googling
I fixed it in 2 steps.
1. ln -s /usr/src/kernels/*2.6.32-220.**el6.x86_64*
/lib/modules/2.6.32-220.el6.x86_64/*build*
2. ln -s
/lib/modules/2.6.32-220.el6.x86_64/*build*/lib/modules/2.6.32-220.el6.x86_64/
*source*
Can s
Hi All,
Can anyone please through some light on what is block size in networking
and how does it effect the TCP/UDP throughput?
Thanks
Clove
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On Wed, Nov 27, 2013 at 9:57 PM, 乃宏周 wrote:
> In module code:
>
> *unsigned char buf[20];*
>
> *struct file *device;*
>
> *device = filp_open(...);*
>
> *device->f_op->read(device,buf,20,&device->f_pos);*
>
> In signature(interface) of *read()* of *struct file*, *buf* should came
> from user-spac
what you said about ip_rcv() should work, since it is even earlier than
tcp, so no problem.
your ip address translation is exactly what NAT is doing, so u definitely
can remap it to what address u like.
but port + IP address does not imply anything about which NIC port it is
coming from. perhap
