Re: [PATCH] Fixes for RCU handling of task_struct

From: Paul E. McKenney
Date: Thu Nov 03 2005 - 14:09:07 EST


On Mon, Oct 31, 2005 at 08:51:19PM -0800, Andrew Morton wrote:
> Ingo Molnar <mingo@xxxxxxx> wrote:
> >
> > @@ -1433,7 +1485,16 @@ send_group_sigqueue(int sig, struct sigq
> > int ret = 0;
> >
> > BUG_ON(!(q->flags & SIGQUEUE_PREALLOC));
> > - read_lock(&tasklist_lock);
> > +
> > + while(!read_trylock(&tasklist_lock)) {
> > + if (!p->sighand)
> > + return -1;
> > + cpu_relax();
> > + }
>
> This looks kind of ugly and quite unobvious.
>
> What's going on there?

This was discussed in the following thread:

http://marc.theaimsgroup.com/?l=linux-kernel&m=112756875713008&w=2

Looks like its author asked for it to be withdrawn in favor of Roland's
"[PATCH] Call exit_itimers from do_exit, not __exit_signal" patch:

http://marc.theaimsgroup.com/?l=linux-kernel&m=113008567108608&w=2

My guess is that "Roland" is "Roland McGrath", but I cannot find the
referenced patch. Oleg, any enlightenment?

Thanx, Paul
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