Re: [PATCH] memcg: Fix race condition in memcg_check_events() withthis_cpu usage

[KAMEZAWA Hiroyuki]

On Fri, 23 Sep 2011 20:54:42 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> From: Steven Rostedt <srostedt@xxxxxxxxxx>
> 
> The code in memcg_check_events() calls this_cpu_read() on
> different variables without disabling preemption, and can cause
> the calculations to be done from two different CPU variables.
> 
> Disable preemption throughout the check to keep apples and oranges
> from becoming a mixed drink.
> 
> [ Added this_cpu to __this_cpu conversion by Johannes ]
> 
> Cc: Greg Thelen <gthelen@xxxxxxxxxx>
> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
> Cc: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
> Cc: Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Christoph Lameter <cl@xxxxxxxxx>
> Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Link: http://lkml.kernel.org/r/20110919212641.015320989@xxxxxxxxxxx

Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>

Andrew, could you pick this up ?

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