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Subject: Re: [PATCH] posix-timer: fix deletion race
From: Thomas Gleixner <tglx@linutronix.de>
To: Jeremy Katz <jeremy.katz@windriver.com>
Cc: linux-kernel@vger.kernel.org, Andrew Morton <akpm@osdl.org>,
       Ingo Molnar <mingo@elte.hu>, Oleg Nesterov <oleg@tv-sign.ru>,
       Stable Team <stable@kernel.org>
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Date: Thu, 19 Jul 2007 07:50:21 +0200
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On Wed, 2007-07-18 at 16:43 -0700, Jeremy Katz wrote:
> On Wed, 18 Jul 2007, Jeremy Katz wrote:
> 
> > On Wed, 18 Jul 2007, Thomas Gleixner wrote:
> >
> >>> Also can you please enable CONFIG_PROVE_LOCKING, which might catch any
> >>> locking problem, which might be related to this.
> >> 
> >> Another test: Can you please disable CONFIG_SCHED_SMT to narrow it down
> >> further ?
> >
> > I'll try both of these.
> 
> I'm still seeing the sys_timer_delete version with your patch, and 
> sys_timer_delete and posix_timer_event without. The itimer_delete version 
> is currently missing in action, but getting any particular one to perform 
> on demand is currently not in my power.

Ok, let me summarize:

2.6.22 + hrt6

Both problems are there whether CONFIG_SCHED_SMT is on or not

2.6.22 + hrt6 + posixtimer patch

Both problems are there whether CONFIG_SCHED_SMT is on
The timer callback problem is gone when CONFIG_SCHED_SMT is off

Correct ?

	tglx