mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

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>
This commit is contained in:
Christophe JAILLET 2023-04-20 22:27:24 +02:00 committed by Will Deacon
parent 44c026a73b
commit f818947a06
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/perf/arm-cci.c
View File

@ -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;
}
}