SIGKILL

[Darshan Ghumare]

On Fri, Jan 20, 2012 at 12:32 PM, Dave Hylands <dhylands at gmail.com> wrote:

> Hi Darshan,
>
HI Dave,


>
> Replying to all this time....
>
Thanks.

>
> On Thu, Jan 19, 2012 at 9:41 PM, Darshan Ghumare
> <darshan.ghumare at gmail.com> wrote:
> ...snip...
> > What if,
> > spin_lock_irqsave(&lock, flags);
> > for ( ; ; )
> > {
> >        ;
> > }
> > spin_lock_irqrestore(&lock, flags);
>
> Since you're using spinlocks and disabling interrupts, this would be
> running in kernel space.
>
> On a single core machine - you'll have locked up your entire computer.
>
> On a multi-core machine you'll have locked up one core.
>
> You don't need to use the spinlock, just disabling interrupts is
> sufficient. Even on a multicore machine, the spinlocks would just
> prevent a second core from executing the code if it tried to acquire
> the same spinlock.
>
> I don't think that there is any convenient way to kill such a thread.
>
IMHO, signals are handled when process is about to switch back to user-mode.
If that is the case then what if, there are two threads(in user-mode) in
the process where one is stuck
in the syscall which has infinite loop & other is executing some task in
the user-mode, then still this process can not be killed?

>
> --
> Dave Hylands
> Shuswap, BC, Canada
> http://www.davehylands.com
>

Regards
Darshan


-- 
Darshan®
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