From: "tip-bot2 for Liang, Kan" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: "Liang, Kan" <kan.liang@linux.intel.com>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Jiri Olsa <jolsa@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Mark Rutland <mark.rutland@arm.com>,
Namhyung Kim <namhyung@kernel.org>,
Stephane Eranian <eranian@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Vince Weaver <vincent.weaver@maine.edu>,
Ingo Molnar <mingo@kernel.org>, Borislav Petkov <bp@alien8.de>,
linux-kernel@vger.kernel.org
Subject: [tip: perf/core] perf/core: Optimize perf_init_event() for TYPE_SOFTWARE
Date: Mon, 28 Oct 2019 12:43:17 -0000 [thread overview]
Message-ID: <157226659774.29376.11587351641119778344.tip-bot2@tip-bot2> (raw)
The following commit has been merged into the perf/core branch of tip:
Commit-ID: d44f821b0e13275735e8f3fe4db8703b45f05d52
Gitweb: https://git.kernel.org/tip/d44f821b0e13275735e8f3fe4db8703b45f05d52
Author: Liang, Kan <kan.liang@linux.intel.com>
AuthorDate: Tue, 22 Oct 2019 11:13:09 +02:00
Committer: Ingo Molnar <mingo@kernel.org>
CommitterDate: Mon, 28 Oct 2019 12:53:28 +01:00
perf/core: Optimize perf_init_event() for TYPE_SOFTWARE
Andi reported that he was hitting the linear search in
perf_init_event() a lot. Now that all !TYPE_SOFTWARE events should hit
the IDR, make sure the TYPE_SOFTWARE events are at the head of the
list such that we'll quickly find the right PMU (provided a valid
event was given).
Signed-off-by: Liang, Kan <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
kernel/events/core.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 4d67c5d..cfd89b4 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -10180,7 +10180,16 @@ got_cpu_context:
if (!pmu->event_idx)
pmu->event_idx = perf_event_idx_default;
- list_add_rcu(&pmu->entry, &pmus);
+ /*
+ * Ensure the TYPE_SOFTWARE PMUs are at the head of the list,
+ * since these cannot be in the IDR. This way the linear search
+ * is fast, provided a valid software event is provided.
+ */
+ if (type == PERF_TYPE_SOFTWARE || !name)
+ list_add_rcu(&pmu->entry, &pmus);
+ else
+ list_add_tail_rcu(&pmu->entry, &pmus);
+
atomic_set(&pmu->exclusive_cnt, 0);
ret = 0;
unlock:
reply other threads:[~2019-10-28 12:43 UTC|newest]
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