From: Darren Hart <dvhart@linux.intel.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH] [RESEND 2] Take over futex of dead task only if FUTEX_WAITERS is not set
Date: Thu, 25 Oct 2012 01:18:24 -0700 [thread overview]
Message-ID: <5088F5D0.7010604@linux.intel.com> (raw)
In-Reply-To: <alpine.LFD.2.02.1210250936270.2756@ionos>
On 10/25/2012 01:14 AM, Thomas Gleixner wrote:
> On Wed, 24 Oct 2012, Darren Hart wrote:
>> On 10/23/2012 01:29 PM, Thomas Gleixner wrote:
> Nah. I'm just too paranoid to apply any futex patch w/o understanding
> the root cause of it. Darn, if I only could remember how that stale
> waiters bit issue got inflicted ....
Stale waiters happens in userspace for non-pi mutexes and there we make
one extra FUTEX_WAKE syscall just in case. The futex value policy is much
more rigid with PI obviously, so I wasn't aware this could happen there.
--
Darren Hart
Intel Open Source Technology Center
Yocto Project - Technical Lead - Linux Kernel
next prev parent reply other threads:[~2012-10-25 8:19 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-11 14:52 [PATCH] Take over futex of dead task only if FUTEX_WAITERS is not set Siddhesh Poyarekar
2012-10-17 7:15 ` [PATCH RESEND] " Siddhesh Poyarekar
2012-10-22 3:20 ` [PATCH] [RESEND 2] " Siddhesh Poyarekar
2012-10-23 14:04 ` Darren Hart
2012-10-23 20:29 ` Thomas Gleixner
2012-10-24 12:48 ` Siddhesh Poyarekar
2012-10-24 18:08 ` Thomas Gleixner
2012-10-25 4:36 ` Darren Hart
2012-10-25 4:44 ` Siddhesh Poyarekar
2012-10-25 4:33 ` Darren Hart
2012-10-25 8:14 ` Thomas Gleixner
2012-10-25 8:18 ` Darren Hart [this message]
2012-11-01 21:35 ` [tip:core/urgent] futex: Handle futex_pi OWNER_DIED take over correctly tip-bot for Thomas Gleixner
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