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From: Yajun Deng <yajun.deng@linux.dev>
To: peterz@infradead.org, mingo@redhat.com, acme@kernel.org,
	mark.rutland@arm.com, alexander.shishkin@linux.intel.com,
	jolsa@kernel.org, namhyung@kernel.org, eranian@google.com
Cc: linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
	Yajun Deng <yajun.deng@linux.dev>
Subject: [PATCH] perf/core: fix perf_event_mux_interval_ms when set zero
Date: Tue, 14 Jun 2022 18:37:51 +0800	[thread overview]
Message-ID: <20220614103751.1395645-1-yajun.deng@linux.dev> (raw)

The perf_event_mux_interval_ms is set to zero or one by default.
It can't change back when someone changes it from zero to another
value.

Make perf_event_mux_interval_ms to PERF_CPU_HRTIMER when set zero.

Fixes: 62b856397927 ("perf: Add sysfs entry to adjust multiplexing interval per PMU")
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
---
 kernel/events/core.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 61ad10862c21..73c8c7462bbf 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -10954,9 +10954,12 @@ perf_event_mux_interval_ms_store(struct device *dev,
 	if (ret)
 		return ret;
 
-	if (timer < 1)
+	if (timer < 0)
 		return -EINVAL;
 
+	if (timer < 1)
+		timer = PERF_CPU_HRTIMER;
+
 	/* same value, noting to do */
 	if (timer == pmu->hrtimer_interval_ms)
 		return count;
-- 
2.25.1


             reply	other threads:[~2022-06-14 10:38 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-14 10:37 Yajun Deng [this message]
2022-06-14 22:08 ` [PATCH] perf/core: fix perf_event_mux_interval_ms when set zero Namhyung Kim
2022-06-15  1:29   ` Yajun Deng

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