tree db624be62586a59c5f3954bf7c8c9188fa58d819
parent 2c53b436a30867eb6b47dd7bab23ba638d1fb0d2
author Robert Richter <robert.richter@amd.com> 1306935104 +0200
committer Robert Richter <robert.richter@amd.com> 1308141089 +0200

oprofile, x86: Fix race in nmi handler while starting counters

In some rare cases, nmis are generated immediately after the nmi
handler of the cpu was started. This causes the counter not to be
enabled. Before enabling the nmi handlers we need to set variable
ctr_running first and make sure its value is written to memory.

Also, the patch makes all existing barriers a memory barrier instead
of a compiler barrier only.

Reported-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: <stable@kernel.org> # .35+
Signed-off-by: Robert Richter <robert.richter@amd.com>