Re: [patch 12/13] cpufreq/sparc-us2e: Replace racy task affinity logic

[Viresh Kumar]

On 12-04-17, 22:07, Thomas Gleixner wrote:
> The access to the HBIRD_ESTAR_MODE register in the cpu frequency control
> functions must happen on the target 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 a straight forward smp function call. 
> 
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
> Cc: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
> Cc: linux-pm@xxxxxxxxxxxxxxx
> ---
>  drivers/cpufreq/sparc-us2e-cpufreq.c |   45 ++++++++++++++++-------------------
>  1 file changed, 21 insertions(+), 24 deletions(-)

Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>

-- 
viresh