From: Marc Zyngier <Marc.Zyngier@arm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>,
Yong Zhang <yong.zhang0@gmail.com>, Ingo Molnar <mingo@elte.hu>,
Frank Rowand <frank.rowand@am.sony.com>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [BUG] "sched: Remove rq->lock from the first half of ttwu()" locks up on ARM
Date: Thu, 26 May 2011 17:20:23 +0100 [thread overview]
Message-ID: <1306426823.27474.241.camel@e102391-lin.cambridge.arm.com> (raw)
In-Reply-To: <1306426148.2497.83.camel@laptop>
On Thu, 2011-05-26 at 18:09 +0200, Peter Zijlstra wrote:
> On Thu, 2011-05-26 at 17:59 +0200, Peter Zijlstra wrote:
> > On Thu, 2011-05-26 at 17:45 +0200, Oleg Nesterov wrote:
> > > Stupid question. Can't we fix this problem if we do
> > >
> > > - if (p == current)
> > > + if (cpu == raw_smp_processor_id())
> > >
> > > ?
> > >
> > > I forgot the rules... but iirc task_cpu(p) can't be changed under us?
> >
> > Easy enough to test.. brain gave out again,. hold on ;-)
>
> The below seems to run all-right so far, I'll let it run for a while.
Doesn't look very good here. The serial console basically locks up as
soon as the system gets busy, even if the kernel compilation seem to
progress at a decent pace.
M.
--
Reality is an implementation detail.
WARNING: multiple messages have this Message-ID (diff)
From: Marc.Zyngier@arm.com (Marc Zyngier)
To: linux-arm-kernel@lists.infradead.org
Subject: [BUG] "sched: Remove rq->lock from the first half of ttwu()" locks up on ARM
Date: Thu, 26 May 2011 17:20:23 +0100 [thread overview]
Message-ID: <1306426823.27474.241.camel@e102391-lin.cambridge.arm.com> (raw)
In-Reply-To: <1306426148.2497.83.camel@laptop>
On Thu, 2011-05-26 at 18:09 +0200, Peter Zijlstra wrote:
> On Thu, 2011-05-26 at 17:59 +0200, Peter Zijlstra wrote:
> > On Thu, 2011-05-26 at 17:45 +0200, Oleg Nesterov wrote:
> > > Stupid question. Can't we fix this problem if we do
> > >
> > > - if (p == current)
> > > + if (cpu == raw_smp_processor_id())
> > >
> > > ?
> > >
> > > I forgot the rules... but iirc task_cpu(p) can't be changed under us?
> >
> > Easy enough to test.. brain gave out again,. hold on ;-)
>
> The below seems to run all-right so far, I'll let it run for a while.
Doesn't look very good here. The serial console basically locks up as
soon as the system gets busy, even if the kernel compilation seem to
progress at a decent pace.
M.
--
Reality is an implementation detail.
next prev parent reply other threads:[~2011-05-26 16:19 UTC|newest]
Thread overview: 102+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-24 18:13 [BUG] "sched: Remove rq->lock from the first half of ttwu()" locks up on ARM Marc Zyngier
2011-05-24 18:13 ` Marc Zyngier
2011-05-24 21:32 ` Peter Zijlstra
2011-05-24 21:32 ` Peter Zijlstra
2011-05-24 21:39 ` Ingo Molnar
2011-05-24 21:39 ` Ingo Molnar
2011-05-25 12:23 ` Marc Zyngier
2011-05-25 12:23 ` Marc Zyngier
2011-05-25 17:08 ` Peter Zijlstra
2011-05-25 17:08 ` Peter Zijlstra
2011-05-25 21:15 ` Peter Zijlstra
2011-05-25 21:15 ` Peter Zijlstra
2011-05-26 7:29 ` Yong Zhang
2011-05-26 7:29 ` Yong Zhang
2011-05-26 10:32 ` Peter Zijlstra
2011-05-26 10:32 ` Peter Zijlstra
2011-05-26 11:02 ` Marc Zyngier
2011-05-26 11:02 ` Marc Zyngier
2011-05-26 11:32 ` Peter Zijlstra
2011-05-26 11:32 ` Peter Zijlstra
2011-05-26 12:21 ` Peter Zijlstra
2011-05-26 12:21 ` Peter Zijlstra
2011-05-26 12:26 ` Ingo Molnar
2011-05-26 12:26 ` Ingo Molnar
2011-05-26 12:31 ` Russell King - ARM Linux
2011-05-26 12:31 ` Russell King - ARM Linux
2011-05-26 12:37 ` Peter Zijlstra
2011-05-26 12:37 ` Peter Zijlstra
2011-05-26 12:50 ` Ingo Molnar
2011-05-26 12:50 ` Ingo Molnar
2011-05-26 13:36 ` Russell King - ARM Linux
2011-05-26 13:36 ` Russell King - ARM Linux
2011-05-26 14:45 ` Catalin Marinas
2011-05-26 14:45 ` Catalin Marinas
2011-05-27 12:06 ` Ingo Molnar
2011-05-27 12:06 ` Ingo Molnar
2011-05-27 17:55 ` Russell King - ARM Linux
2011-05-27 17:55 ` Russell King - ARM Linux
2011-05-27 19:41 ` Nicolas Pitre
2011-05-27 19:41 ` Nicolas Pitre
2011-05-27 20:52 ` Russell King - ARM Linux
2011-05-27 20:52 ` Russell King - ARM Linux
2011-05-28 13:13 ` Peter Zijlstra
2011-05-28 13:13 ` Peter Zijlstra
2011-05-31 11:08 ` Michal Simek
2011-05-31 11:08 ` Michal Simek
2011-05-31 13:22 ` Peter Zijlstra
2011-05-31 13:22 ` Peter Zijlstra
2011-05-31 13:37 ` Michal Simek
2011-05-31 13:37 ` Michal Simek
2011-05-31 13:52 ` Peter Zijlstra
2011-05-31 13:52 ` Peter Zijlstra
2011-05-31 14:08 ` Michal Simek
2011-05-31 14:08 ` Michal Simek
2011-05-31 14:29 ` Peter Zijlstra
2011-05-31 14:29 ` Peter Zijlstra
2011-05-29 10:21 ` Catalin Marinas
2011-05-29 10:21 ` Catalin Marinas
2011-05-29 10:26 ` Russell King - ARM Linux
2011-05-29 10:26 ` Russell King - ARM Linux
2011-05-29 12:01 ` Catalin Marinas
2011-05-29 12:01 ` Catalin Marinas
2011-05-29 13:19 ` Russell King - ARM Linux
2011-05-29 13:19 ` Russell King - ARM Linux
2011-05-29 21:21 ` Catalin Marinas
2011-05-29 21:21 ` Catalin Marinas
2011-05-29 9:51 ` Catalin Marinas
2011-05-29 9:51 ` Catalin Marinas
2011-06-06 10:29 ` Pavel Machek
2011-06-06 10:29 ` Pavel Machek
2011-05-26 14:56 ` Marc Zyngier
2011-05-26 14:56 ` Marc Zyngier
2011-05-26 15:45 ` Oleg Nesterov
2011-05-26 15:45 ` Oleg Nesterov
2011-05-26 15:59 ` Peter Zijlstra
2011-05-26 15:59 ` Peter Zijlstra
2011-05-26 16:09 ` Peter Zijlstra
2011-05-26 16:09 ` Peter Zijlstra
2011-05-26 16:20 ` Marc Zyngier [this message]
2011-05-26 16:20 ` Marc Zyngier
2011-05-26 16:32 ` Peter Zijlstra
2011-05-26 16:32 ` Peter Zijlstra
2011-05-27 8:01 ` Marc Zyngier
2011-05-27 8:01 ` Marc Zyngier
2011-05-26 16:22 ` Marc Zyngier
2011-05-26 16:22 ` Marc Zyngier
2011-05-26 17:04 ` Oleg Nesterov
2011-05-26 17:04 ` Oleg Nesterov
2011-05-26 17:17 ` Peter Zijlstra
2011-05-26 17:17 ` Peter Zijlstra
2011-05-26 17:23 ` Peter Zijlstra
2011-05-26 17:23 ` Peter Zijlstra
2011-05-26 17:49 ` Oleg Nesterov
2011-05-26 17:49 ` Oleg Nesterov
2011-05-27 7:01 ` Yong Zhang
2011-05-27 7:01 ` Yong Zhang
2011-05-27 15:23 ` Santosh Shilimkar
2011-05-27 15:23 ` Santosh Shilimkar
2011-05-27 15:29 ` Marc Zyngier
2011-05-27 15:29 ` Marc Zyngier
2011-05-27 15:30 ` Santosh Shilimkar
2011-05-27 15:30 ` Santosh Shilimkar
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