From: catalin.marinas@arm•com (Catalin Marinas)
To: linux-arm-kernel@lists•infradead.org
Subject: BUG: commit "ARM: Remove __ARCH_WANT_INTERRUPTS_ON_CTXSW on pre-ARMv6 CPUs" breaks armv5 with CONFIG_PREEMPT
Date: Fri, 21 Jun 2013 14:52:19 +0100 [thread overview]
Message-ID: <20130621135219.GC4099@arm.com> (raw)
In-Reply-To: <51C42AE0.9070506@pengutronix.de>
On Fri, Jun 21, 2013 at 11:28:48AM +0100, Marc Kleine-Budde wrote:
> On 06/20/2013 01:47 PM, Marc Kleine-Budde wrote:
> > From 306d84d5f0645a86e86d539be0546c4ac758d3d4 Mon Sep 17 00:00:00 2001
> > From: Catalin Marinas <catalin.marinas@arm•com>
> > Date: Thu, 20 Jun 2013 12:12:55 +0100
> > Subject: [PATCH] arm: Fix deferred mm switch on VIVT processors
> >
> > As of commit b9d4d42ad9 (ARM: Remove __ARCH_WANT_INTERRUPTS_ON_CTXSW on
> > pre-ARMv6 CPUs), the mm switching on VIVT processors is done in the
> > finish_arch_post_lock_switch() function to avoid whole cache flushing
> > with interrupts disabled. The need for deferred mm switch is stored as a
> > thread flag (TIF_SWITCH_MM). However, with preemption enabled, we can
> > have another thread switch before finish_arch_post_lock_switch(). If the
> > new thread has the same mm as the previous 'next' thread, the scheduler
> > will not call switch_mm() and the TIF_SWITCH_MM flag won't be set for
> > the new thread.
> >
> > This patch moves the switch pending flag to the mm_context_t structure
> > since this is specific to the mm rather than thread.
> >
> > Signed-off-by: Catalin Marinas <catalin.marinas@arm•com>
> > Reported-by: Marc Kleine-Budde <mkl@pengutronix•de>
> > [mkl: add check for mm]
> > Signed-off-by: Marc Kleine-Budde <mkl@pengutronix•de>
>
> Works on $CUSTOMERS's hardware.
>
> Tested-by: Marc Kleine-Budde <mkl@pengutronix•de>
Thanks.
> Catalin, do you take care of the patch? Please add stable on Cc. The fix
> is needed on kernels >= v3.5.
I'll send it to Russell, if possible it should go in for 3.10. I already
added CC stable in my copy (3.5+).
--
Catalin
next prev parent reply other threads:[~2013-06-21 13:52 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-20 8:43 BUG: commit "ARM: Remove __ARCH_WANT_INTERRUPTS_ON_CTXSW on pre-ARMv6 CPUs" breaks armv5 with CONFIG_PREEMPT Marc Kleine-Budde
2013-06-20 9:25 ` Will Deacon
2013-06-20 9:51 ` Marc Kleine-Budde
2013-06-20 9:57 ` Catalin Marinas
2013-06-20 10:08 ` Marc Kleine-Budde
2013-06-20 10:14 ` Marc Kleine-Budde
2013-06-20 10:28 ` Catalin Marinas
2013-06-20 11:12 ` Catalin Marinas
2013-06-20 11:35 ` Marc Kleine-Budde
2013-06-20 11:39 ` Marc Kleine-Budde
2013-06-20 11:47 ` Marc Kleine-Budde
2013-06-20 12:48 ` Marc Kleine-Budde
2013-06-20 13:01 ` Catalin Marinas
2013-06-20 13:05 ` Marc Kleine-Budde
2013-06-21 10:28 ` Marc Kleine-Budde
2013-06-21 13:52 ` Catalin Marinas [this message]
2013-07-17 8:41 ` Marc Kleine-Budde
2013-07-17 8:51 ` Russell King - ARM Linux
2013-07-17 11:48 ` Marc Kleine-Budde
2013-07-17 19:41 ` Catalin Marinas
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