[PATCH 33/49] perf: replace bitmap_weight with bitmap_weight_eq for ThunderX2

Yury Norov
2022-02-11T00:06:17Z

tx2_uncore_event_start() calls bitmap_weight() to compare the weight
of bitmap with a given number. We can do it more efficiently with
bitmap_weight_eq because conditional bitmap_weight may stop traversing
the bitmap earlier, as soon as condition is (or can't be) met.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
drivers/perf/thunderx2_pmu.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/perf/thunderx2_pmu.c b/drivers/perf/thunderx2_pmu.c
index 1edb9c03704f..97d5b39778fa 100644
--- a/drivers/perf/thunderx2_pmu.c
+++ b/drivers/perf/thunderx2_pmu.c
@@ -623,8 +623,8 @@ static void tx2_uncore_event_start(struct perf_event *event, int flags)
return;

/* Start timer for first event */
- if (bitmap_weight(tx2_pmu->active_counters,
- tx2_pmu->max_counters) == 1) {
+ if (bitmap_weight_eq(tx2_pmu->active_counters,
+ tx2_pmu->max_counters, 1)) {
hrtimer_start(&tx2_pmu->hrtimer,
ns_to_ktime(tx2_pmu->hrtimer_interval),
HRTIMER_MODE_REL_PINNED);
--
2.32.0