UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity

perf/arm-cci: Remove unnecessary period adjustment 

Since sampling events are rejected up-front by cci_pmu_event_init(), it
doesn't make much sense to go fiddling with the sampling period later.
This would seem to be just another leftover artefact of the arm_pmu
framwork, and as such can go.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Robin Murphy 2018-05-21 12:17:09 +01:00 committed by Will Deacon
parent d0f2e42329
commit 5c591304e7
1 changed files with 0 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
drivers/perf/arm-cci.c
View File

@ -1304,15 +1304,6 @@ static int __hw_perf_event_init(struct perf_event *event)
*/
hwc->config_base |= (unsigned long)mapping;
/*
* Limit the sample_period to half of the counter width. That way, the
* new counter value is far less likely to overtake the previous one
* unless you have some serious IRQ latency issues.
*/
hwc->sample_period = CCI_PMU_CNTR_MASK >> 1;
hwc->last_period = hwc->sample_period;
local64_set(&hwc->period_left, hwc->sample_period);
if (event->group_leader != event) {
if (validate_group(event) != 0)
return -EINVAL;