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| author | Stephane Eranian <eranian@google.com> | 2010-02-01 13:50:01 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-02-04 09:59:50 +0100 |
| commit | 447a194b393f32699607fd99617a40abd6a95114 (patch) | |
| tree | 7d202a6ad8f80c913a4e3d439eedf5ba0abbbf39 /tools | |
| parent | bitops: Ensure the compile time HWEIGHT is only used for such (diff) | |
| download | linux-447a194b393f32699607fd99617a40abd6a95114.tar.xz linux-447a194b393f32699607fd99617a40abd6a95114.zip | |
perf_events, x86: Fix bug in hw_perf_enable()
We cannot assume that because hwc->idx == assign[i], we can avoid
reprogramming the counter in hw_perf_enable().
The event may have been scheduled out and another event may have been
programmed into this counter. Thus, we need a more robust way of
verifying if the counter still contains config/data related to an event.
This patch adds a generation number to each counter on each cpu. Using
this mechanism we can verify reliabilty whether the content of a counter
corresponds to an event.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4b66dc67.0b38560a.1635.ffffae18@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'tools')
0 files changed, 0 insertions, 0 deletions