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Message-Id: <9e5b7638ff44111334aff53b76bdcd1f26f08179.1526901337.git.robin.murphy@arm.com>
Date: Mon, 21 May 2018 12:17:09 +0100
From: Robin Murphy <robin.murphy@....com>
To: will.deacon@....com, mark.rutland@....com
Cc: linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH] 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@....com>
Signed-off-by: Robin Murphy <robin.murphy@....com>
---
drivers/perf/arm-cci.c | 9 ---------
1 file changed, 9 deletions(-)
diff --git a/drivers/perf/arm-cci.c b/drivers/perf/arm-cci.c
index 09938dd8eb6f..e6fadc8e1178 100644
--- a/drivers/perf/arm-cci.c
+++ b/drivers/perf/arm-cci.c
@@ -1297,15 +1297,6 @@ 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;
--
2.17.0.dirty
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