[RFC][PATCH 04/11] perf, x86: Use unlocked bitops
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From: Peter Zijlstra on 3 Mar 2010 11:50 There is no concurrency on these variables, so don't use LOCK'ed ops. Signed-off-by: Peter Zijlstra <a.p.zijlstra(a)chello.nl> --- arch/x86/kernel/cpu/perf_event.c | 8 ++++---- arch/x86/kernel/cpu/perf_event_amd.c | 2 +- arch/x86/kernel/cpu/perf_event_intel.c | 2 +- 3 files changed, 6 insertions(+), 6 deletions(-) Index: linux-2.6/arch/x86/kernel/cpu/perf_event.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/cpu/perf_event.c +++ linux-2.6/arch/x86/kernel/cpu/perf_event.c @@ -638,7 +638,7 @@ static int x86_schedule_events(struct cp if (test_bit(hwc->idx, used_mask)) break; - set_bit(hwc->idx, used_mask); + __set_bit(hwc->idx, used_mask); if (assign) assign[i] = hwc->idx; } @@ -687,7 +687,7 @@ static int x86_schedule_events(struct cp if (j == X86_PMC_IDX_MAX) break; - set_bit(j, used_mask); + __set_bit(j, used_mask); if (assign) assign[i] = j; @@ -837,7 +837,7 @@ void hw_perf_enable(void) * clear active_mask and events[] yet it preserves * idx */ - set_bit(hwc->idx, cpuc->active_mask); + __set_bit(hwc->idx, cpuc->active_mask); cpuc->events[hwc->idx] = event; x86_pmu.enable(event); @@ -1052,7 +1052,7 @@ static void x86_pmu_stop(struct perf_eve * Must be done before we disable, otherwise the nmi handler * could reenable again: */ - clear_bit(idx, cpuc->active_mask); + __clear_bit(idx, cpuc->active_mask); x86_pmu.disable(event); /* Index: linux-2.6/arch/x86/kernel/cpu/perf_event_amd.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_amd.c +++ linux-2.6/arch/x86/kernel/cpu/perf_event_amd.c @@ -309,7 +309,7 @@ static struct amd_nb *amd_alloc_nb(int c * initialize all possible NB constraints */ for (i = 0; i < x86_pmu.num_events; i++) { - set_bit(i, nb->event_constraints[i].idxmsk); + __set_bit(i, nb->event_constraints[i].idxmsk); nb->event_constraints[i].weight = 1; } return nb; Index: linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_intel.c +++ linux-2.6/arch/x86/kernel/cpu/perf_event_intel.c @@ -768,7 +768,7 @@ again: for_each_bit(bit, (unsigned long *)&status, X86_PMC_IDX_MAX) { struct perf_event *event = cpuc->events[bit]; - clear_bit(bit, (unsigned long *) &status); + __clear_bit(bit, (unsigned long *) &status); if (!test_bit(bit, cpuc->active_mask)) continue; -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |