From: Viresh Kumar <viresh.kumar@linaro.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Sebastian Siewior <bigeasy@linutronix.de>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
"David S. Miller" <davem@davemloft.net>,
Fenghua Yu <fenghua.yu@intel.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Len Brown <lenb@kernel.org>,
Michael Ellerman <mpe@ellerman.id.au>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Tejun Heo <tj@kernel.org>, Tony Luck <tony.luck@intel.com>,
linux-pm@vger.kernel.org
Subject: Re: [patch 09/13] cpufreq/ia64: Replace racy task affinity logic
Date: Thu, 13 Apr 2017 08:12:49 +0530 [thread overview]
Message-ID: <20170413024249.GI5910@vireshk-i7> (raw)
In-Reply-To: <20170412201042.865458445@linutronix.de>
On 12-04-17, 22:07, Thomas Gleixner wrote:
> The get() and target() callbacks must run on the affected cpu. This is
> achieved by temporarily setting the affinity of the calling thread to the
> requested CPU and reset it to the original affinity afterwards.
>
> That's racy vs. concurrent affinity settings for that thread resulting in
> code executing on the wrong CPU and overwriting the new affinity setting.
>
> Replace it by work_on_cpu(). All call pathes which invoke the callbacks are
> already protected against CPU hotplug.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Cc: Viresh Kumar <viresh.kumar@linaro.org>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: Fenghua Yu <fenghua.yu@intel.com>
> Cc: linux-pm@vger.kernel.org
> ---
> drivers/cpufreq/ia64-acpi-cpufreq.c | 91 +++++++++++++++---------------------
> 1 file changed, 38 insertions(+), 53 deletions(-)
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
--
viresh
next prev parent reply other threads:[~2017-04-13 2:42 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 ` Viresh Kumar [this message]
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 ` [patch V2 " David Miller
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