lkml.org 
[lkml]   [2007]   [May]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [BUG] futex_unlock_pi() hurts my brain and may cause application deadlock
From
Date
On Thu, 2007-05-31 at 16:24 +0200, Ingo Molnar wrote:
> * john stultz <johnstul@us.ibm.com> wrote:
>
> > So we've been seeing PI mutex deadlocks with a few of our
> > applications using the -rt kernel. After narrowing things down, we
> > were finding that the applications were indirectly calling
> > futex_unlock_pi(), which on occasion would return -EFAULT, which is
> > promptly ignored by glibc. This would cause the application to
> > continue on as if it has unlocked the mutex, until it tried to
> > reacquire it and deadlock.
>
> > --- a/kernel/futex.c
> > +++ b/kernel/futex.c
> > @@ -2011,6 +2011,7 @@ pi_faulted:
> > attempt);
> > if (ret)
> > goto out_unlock;
> > + uval = 0;
> > goto retry_locked;
>
> this looks good to me. Oleg has posted a few more fixes as well - have
> you tried those too?

Do you have a URL or subject line for the discussion?
I'll take a look and give them a whirl.

thanks
-john

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-05-31 16:53    [from the cache]
©2003-2011 Jasper Spaans