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

diff --git a/drivers/perf/arm-cci.c b/drivers/perf/arm-cci.c
index 03b1309875aeaf3921006c04a872c6d2280d3ab2..998259f1d973ad9bb074e573bf6081036b0b498e 100644 (file)
--- a/drivers/perf/arm-cci.c
+++ b/drivers/perf/arm-cci.c
@@ -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;
                }
        }