SIGKILL

[Mulyadi Santosa]

Hi Darshan :)

On Thu, Jan 19, 2012 at 14:03, Darshan Ghumare
<darshan.ghumare at gmail.com> wrote:
> Hi Mulyadi,
>
> How SIGKILL is handle by Kernel?
> Does SIGKILL & SIGTSTP handled separately than the rest of the signals?

I hope you don't mind if I cc this answer to kernelnewbies as well.
Hopefully you will get better answer.

Well, SIGKILL is handled like other usual signal. The important point
to notice is that sigkill is handled entirely in kernel space. What it
means is that it cannot be overriden in user space (i.e installing
your own signal handler).

SIGKILL will tell the target process to terminate itself. So it pretty
much will flow like normal process termination. However, the
termination will be a bit rough. It will just kill....no time to wait
for in flight I/O whatsoever.

SIGSTOP...ehm, I think that is handled in kernel space too. The
handler will basically move the process out of from run queue to the
process stopped queue (or something like that, I forgot). Then it
switch the process state from "running" to "stop". It's not the same
like "sleep" btw.

Hope it helps....

-- 
regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com