Commit-ID: 19925ce778f9fc371b9607625de3bff04c60121e Gitweb: http://git.kernel.org/tip/19925ce778f9fc371b9607625de3bff04c60121e Author: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> AuthorDate: Sat, 6 Mar 2010 13:20:40 +0100 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Wed, 10 Mar 2010 13:22:33 +0100 perf, x86: Fix double disable calls hw_perf_enable() would disable events that were not yet enabled. This causes problems with code that assumes that ->enable/->disable calls are balanced (like the LBR code does). What happens is that we disable newly added counters that match their previous assignment, even though they are not yet programmed on the hardware. Avoid this by only doing the first pass over the existing events. Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxx> Cc: paulus@xxxxxxxxx Cc: eranian@xxxxxxxxxx Cc: robert.richter@xxxxxxx Cc: fweisbec@xxxxxxxxx LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- arch/x86/kernel/cpu/perf_event.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 071c840..045cc0b 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -802,6 +802,7 @@ void hw_perf_enable(void) return; if (cpuc->n_added) { + int n_running = cpuc->n_events - cpuc->n_added; /* * apply assignment obtained either from * hw_perf_group_sched_in() or x86_pmu_enable() @@ -809,7 +810,7 @@ void hw_perf_enable(void) * step1: save events moving to new counters * step2: reprogram moved events into new counters */ - for (i = 0; i < cpuc->n_events; i++) { + for (i = 0; i < n_running; i++) { event = cpuc->event_list[i]; hwc = &event->hw; -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html