Commit f818947a authored by Christophe JAILLET's avatar Christophe JAILLET Committed by Will Deacon
Browse files

perf/arm-cci: Slightly optimize cci_pmu_sync_counters() 



When the 'mask' bitmap is cleared, it is better to use its full maximum
size instead of only the needed size.
This lets the compiler optimize it because the size is now known at compile
time. HW_CNTRS_MAX is small (i.e. currently 9), so a call to memset() is
saved.

Also, as 'mask' is local to the function, the non-atomic __set_bit() can
also safely be used here.

Signed-off-by: default avatarChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/88d4e20d595f771396e9d558c1587eb4494057db.1682022422.git.christophe.jaillet@wanadoo.fr


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 44c026a7

drivers/perf/arm-cci.c

+2 −2
Original line number Diff line number Diff line
@@ -645,7 +645,7 @@ static void cci_pmu_sync_counters(struct cci_pmu *cci_pmu) 
	struct cci_pmu_hw_events *cci_hw = &cci_pmu->hw_events;

	DECLARE_BITMAP(mask, HW_CNTRS_MAX);



	bitmap_zero(mask, cci_pmu->num_cntrs);

	bitmap_zero(mask, HW_CNTRS_MAX);

	for_each_set_bit(i, cci_pmu->hw_events.used_mask, cci_pmu->num_cntrs) {

		struct perf_event *event = cci_hw->events[i];
@@ -656,7 +656,7 @@ static void cci_pmu_sync_counters(struct cci_pmu *cci_pmu) 
		if (event->hw.state & PERF_HES_STOPPED)

			continue;

		if (event->hw.state & PERF_HES_ARCH) {

			set_bit(i, mask);

			__set_bit(i, mask);

			event->hw.state &= ~PERF_HES_ARCH;

		}

	}