From: David Miller <davem@davemloft.net>
To: tglx@linutronix.de
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
mingo@kernel.org, bigeasy@linutronix.de,
benh@kernel.crashing.org, fenghua.yu@intel.com,
herbert@gondor.apana.org.au, jiangshanlai@gmail.com,
lenb@kernel.org, mpe@ellerman.id.au, rjw@rjwysocki.net,
tj@kernel.org, tony.luck@intel.com, viresh.kumar@linaro.org,
linux-pm@vger.kernel.org
Subject: Re: [patch V2 12/13] cpufreq/sparc-us2e: Replace racy task affinity logic
Date: Thu, 13 Apr 2017 10:50:54 -0400 (EDT) [thread overview]
Message-ID: <20170413.105054.2051423251306433003.davem@davemloft.net> (raw)
In-Reply-To: <alpine.DEB.2.20.1704131017590.2408@nanos>
From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 13 Apr 2017 10:19:07 +0200 (CEST)
> spu_queue_register() needs to invoke setup functions on a particular
> CPU. This is achieved by temporarily setting the affinity of the
> calling user space thread to the requested CPU and reset it to the original
> affinity afterwards.
>
> That's racy vs. CPU hotplug and concurrent affinity settings for that
> thread resulting in code executing on the wrong CPU and overwriting the
> new affinity setting.
>
> Replace it by using work_on_cpu_safe() which guarantees to run the code on
> the requested CPU or to fail in case the CPU is offline.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: David S. Miller <davem@davemloft.net>
prev parent reply other threads:[~2017-04-13 14:50 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20170412200726.941336635@linutronix.de>
2017-04-12 20:07 ` [patch 09/13] cpufreq/ia64: Replace racy task affinity logic Thomas Gleixner
2017-04-12 20:55 ` [patch V2 " Thomas Gleixner
2017-04-13 2:42 ` [patch " Viresh Kumar
2017-04-12 20:07 ` [patch 10/13] cpufreq/sh: " Thomas Gleixner
2017-04-13 2:46 ` Viresh Kumar
2017-04-12 20:07 ` [patch 11/13] cpufreq/sparc-us3: " Thomas Gleixner
2017-04-13 2:48 ` Viresh Kumar
2017-04-12 20:07 ` [patch 12/13] cpufreq/sparc-us2e: " Thomas Gleixner
2017-04-13 2:50 ` Viresh Kumar
2017-04-13 8:19 ` [patch V2 " Thomas Gleixner
2017-04-13 8:22 ` [patch V3 " Thomas Gleixner
2017-04-13 14:50 ` David Miller [this message]
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