perf, x86: Make a second write to performance counter if needed

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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>

...

This commit is contained in:

Cyrill Gorcunov 2010-06-03 01:23:04 +04:00 • committed by Ingo Molnar

parent 8d2cacbbb8

commit 68aa00ac0a

2 changed files with 20 additions and 1 deletions

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12

arch/x86/kernel/cpu/perf_event.c

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9

arch/x86/kernel/cpu/perf_event_p4.c

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