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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2010-03-06 13:24:58 +0100
committerIngo Molnar <mingo@elte.hu>2010-03-10 13:22:35 +0100
commitf3d46b2e6fa57547f9884330798792afc83f4b04 (patch)
tree1c695a1706daf6ef67c940c20a558fb7b9acbfb7 /arch/x86
parent19925ce778f9fc371b9607625de3bff04c60121e (diff)
perf, x86: Fix double enable calls
hw_perf_enable() would enable already enabled events. This causes problems with code that assumes that ->enable/->disable calls are balanced (like the LBR code does). What happens is that events that were already running and left in place would get enabled again. Avoid this by only enabling new events that match their previous assignment. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: paulus@samba.org Cc: eranian@google.com Cc: robert.richter@amd.com Cc: fweisbec@gmail.com LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/cpu/perf_event.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 045cc0bb4c1..1d665a0b202 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -835,6 +835,10 @@ void hw_perf_enable(void)
event = cpuc->event_list[i];
hwc = &event->hw;
+ if (i < n_running &&
+ match_prev_assignment(hwc, cpuc, i))
+ continue;
+
if (hwc->idx == -1)
x86_assign_hw_event(event, cpuc, i);