From: Robin Murphy Date: Mon, 21 May 2018 11:17:09 +0000 (+0100) Subject: perf/arm-cci: Remove unnecessary period adjustment X-Git-Tag: v4.18-rc1~87^2~7^2~8 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=5c591304e710339a75a9f0f9f3f085aa4109e55d;p=linux.git 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 Signed-off-by: Robin Murphy Signed-off-by: Will Deacon --- diff --git a/drivers/perf/arm-cci.c b/drivers/perf/arm-cci.c index 383b2d3dcbc6..72c464485470 100644 --- a/drivers/perf/arm-cci.c +++ b/drivers/perf/arm-cci.c @@ -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;