Date: Tue, 9 Sep 2008 13:41:37 +0100 From: "kr Lekha" <kr.lekha@gmail.com> To: "John Baldwin" <jhb@freebsd.org> Cc: freebsd-current@freebsd.org Subject: Re: Kthread kill Message-ID: <96b2ec350809090541x1035aae6qb59d47c9052ebf29@mail.gmail.com> In-Reply-To: <200809081726.13043.jhb@freebsd.org> References: <96b2ec350809030232v5586ea44nf6ead7d856f72634@mail.gmail.com> <200809081726.13043.jhb@freebsd.org>
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Hi all,
thanks very much for your valuable inputs.
I found out the way to exit the thread.
Problem was psignal(p, SIGKILL); , the p->p_siglist was being reset after
propagating this signal to threads associated with this proc.
Hence i could poll once in a way if any unhandled signals
were in curthread->td_siglist.
I am not sure if this is the optimal solution.
Please do sugest if you have a better solution
Why cant we have signal handlers for kernel threads? when i tried to
register one, sigaction returned value 14 and signal handler didnt get
registered.
Thanks,
lekha
On Mon, Sep 8, 2008 at 10:26 PM, John Baldwin <jhb@freebsd.org> wrote:
> On Wednesday 03 September 2008 05:32:00 am kr Lekha wrote:
> > Hi,
> > i wanted to kill a kthread created by my module, There is no actual
> > kthread_kill to kill it
> >
> > hence I tried to send kill signal to thread
> > psignal(p, SIGTERM);
> > psignal(p, SIGKILL);
> > killproc(p,"messeage");
> > and kthread_suspend()
> >
> > Nothing seems to be killing the kthread, I still see it
> > [root@ /usr/src]# ps awx -l | grep kernel
> > UID PID PPID CPU PRI NI VSZ RSS MWCHAN STAT TT TIME
> > COMMAND 0 1048 1 0 20 0 0 8 ktsusp
> > DL ?? 0:00.01 [new_kernel_thread]
> >
> >
> > I have noticed that generally if kernel module wanted to kill a thread
> then
> > it calls
> > {
> > wakeup(p);
> > msleep(p,0); /*or tsleep*/
> > }
> >
> > This puts the thread to sleep forever. However kthread_suspend also
> > performs same actions.
>
> Your kthread has to explicitly check for a kill request in its main loop
> and
> call kthread_exit() or some such. There is no force-kill for kthreads.
>
> --
> John Baldwin
>
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