From: Steven Rostedt <rostedt@goodmis.org>
To: john stultz <johnstul@us.ibm.com>
Cc: lkml <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@elte.hu>,
Thomas Gleixner <tglx@linutronix.de>,
Sripathi Kodi <sripathik@in.ibm.com>
Subject: Re: [BUG] futex_unlock_pi() hurts my brain and may cause application deadlock
Date: Wed, 30 May 2007 21:29:53 -0400 [thread overview]
Message-ID: <1180574993.21781.22.camel@localhost.localdomain> (raw)
In-Reply-To: <1180572567.6126.44.camel@localhost.localdomain>
On Wed, 2007-05-30 at 17:49 -0700, john stultz wrote:
> ...
> retry_locked:
> /*
> * To avoid races, try to do the TID -> 0 atomic transition
> * again. If it succeeds then we can return without waking
> * anyone else up:
> */
> if (!(uval & FUTEX_OWNER_DIED)) {
> pagefault_disable();
> uval = futex_atomic_cmpxchg_inatomic(uaddr, current->pid, 0);
> pagefault_enable();
> }
My question is to all the futex gurus out there.
This code is in futex_unlock_pi. Can the owner of the mutex really die?
Isn't the owner the one doing the unlock?
-- Steve
next prev parent reply other threads:[~2007-05-31 1:30 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-31 0:49 [BUG] futex_unlock_pi() hurts my brain and may cause application deadlock john stultz
2007-05-31 1:29 ` Steven Rostedt [this message]
2007-05-31 14:53 ` Ulrich Drepper
2007-05-31 2:52 ` [PATCH RT] fix faulting bomb in futex_unlock_pi64 Steven Rostedt
2007-05-31 3:18 ` Steven Rostedt
2007-05-31 17:20 ` Ulrich Drepper
2007-05-31 14:24 ` [BUG] futex_unlock_pi() hurts my brain and may cause application deadlock Ingo Molnar
2007-05-31 14:50 ` john stultz
2007-05-31 14:55 ` Ingo Molnar
2007-05-31 16:48 ` john stultz
2007-07-31 23:53 ` [RESEND] " john stultz
2007-08-01 0:00 ` Steven Rostedt
2007-08-01 1:41 ` David Miller
2007-08-06 7:20 ` Ingo Molnar
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