perf, x86: Make a second write to performance counter if needed
authorCyrill Gorcunov <gorcunov@openvz.org>
Wed, 2 Jun 2010 21:23:04 +0000 (01:23 +0400)
committerIngo Molnar <mingo@elte.hu>
Wed, 9 Jun 2010 09:12:35 +0000 (11:12 +0200)
commit68aa00ac0a82e9a876c799bf6be7622b8f1c8517
treeaf59ed93f50dd539389956e5fe97f3ac0cd85cbe
parent8d2cacbbb8deadfae78aa16e4e1ee619bdd7019e
perf, x86: Make a second write to performance counter if needed

On Netburst PMU we need a second write to a performance counter
due to cpu erratum.

A simple flag test instead of alternative instructions was choosen
because wrmsrl is already a macro and if virtualization is turned
on will need an additional wrapper call which is more expencise.

nb: we should propably switch to jump-labels as only this facility
reach the mainline.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100602212304.GC5264@lenovo>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/kernel/cpu/perf_event.c
arch/x86/kernel/cpu/perf_event_p4.c