tree 94f9113c6870f46811aaa0f08cdb3ca2beba1e9c
parent a61ed3cec51cfd4877855c24890ab8d3e2b143e3
author Steven Rostedt <srostedt@redhat.com> 1320266313 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1320275220 -0700

memcg: Fix race condition in memcg_check_events() with this_cpu usage

Various code in memcontrol.c () calls this_cpu_read() on the calculations
to be done from two different percpu variables, or does an open-coded
read-modify-write on a single percpu variable.

Disable preemption throughout these operations so that the writes go to
the correct palces.

[hannes@cmpxchg.org: added this_cpu to __this_cpu conversion]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>