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| author | Ingo Molnar <mingo@elte.hu> | 2011-04-27 11:51:41 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2011-04-26 19:34:34 +0200 |
| commit | ec75a71634dabe439db91c1ef51d5099f4493808 (patch) | |
| tree | bf62d417bd365f62d4a8afca02a93d37a106a339 /kernel | |
| parent | 18a073a3acd3a47fbb5e23333df7fad28d576345 (diff) | |
| download | linux-ec75a71634dabe439db91c1ef51d5099f4493808.tar.bz2 | |
perf events, x86: Work around the Nehalem AAJ80 erratum
On Nehalem CPUs the retired branch-misses event can be completely bogus,
when there are no branch-misses occuring. When there are a lot of branch
misses then the count is pretty accurate. Still, this leaves us with an
event that over-counts a lot.
Detect this erratum and work it around by using BR_MISP_EXEC.ANY events.
These will also count speculated branches but still it's a lot more
precise in practice than the architectural event.
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/n/tip-yyfg0bxo9jsqxd6a0ovfny27@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
0 files changed, 0 insertions, 0 deletions