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From: tip-bot for Peter Zijlstra <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org,
	peterz@infradead.org, tglx@linutronix.de
Subject: [tip:perf/urgent] perf: Remove fragile swevent hlist optimization
Date: Tue, 19 Nov 2013 11:18:56 -0800	[thread overview]
Message-ID: <tip-06db0b21712f878b808480ef31097637013bbf0f@git.kernel.org> (raw)
In-Reply-To: <20130913111447.GN31370@twins.programming.kicks-ass.net>

Commit-ID:  06db0b21712f878b808480ef31097637013bbf0f
Gitweb:     http://git.kernel.org/tip/06db0b21712f878b808480ef31097637013bbf0f
Author:     Peter Zijlstra <peterz@infradead.org>
AuthorDate: Fri, 13 Sep 2013 13:14:47 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 19 Nov 2013 16:57:42 +0100

perf: Remove fragile swevent hlist optimization

Currently we only allocate a single cpu hashtable for per-cpu
swevents; do away with this optimization for it is fragile in the face
of things like perf_pmu_migrate_context().

The easiest thing is to make sure all CPUs are consistent wrt state.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20130913111447.GN31370@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/events/core.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index d724e77..72348dc 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5680,11 +5680,6 @@ static void swevent_hlist_put(struct perf_event *event)
 {
 	int cpu;
 
-	if (event->cpu != -1) {
-		swevent_hlist_put_cpu(event, event->cpu);
-		return;
-	}
-
 	for_each_possible_cpu(cpu)
 		swevent_hlist_put_cpu(event, cpu);
 }
@@ -5718,9 +5713,6 @@ static int swevent_hlist_get(struct perf_event *event)
 	int err;
 	int cpu, failed_cpu;
 
-	if (event->cpu != -1)
-		return swevent_hlist_get_cpu(event, event->cpu);
-
 	get_online_cpus();
 	for_each_possible_cpu(cpu) {
 		err = swevent_hlist_get_cpu(event, cpu);

      parent reply	other threads:[~2013-11-19 19:19 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-11 13:54 trinity finds ftrace/perf bug. Film at 11 Dave Jones
2013-09-12 18:19 ` Steven Rostedt
2013-09-12 18:38   ` Dave Jones
2013-10-03 15:44     ` Peter Zijlstra
2013-10-03 16:57       ` Ingo Molnar
2013-09-13 10:56   ` Peter Zijlstra
2013-09-13 14:16     ` Dave Jones
2013-09-16  9:37       ` Peter Zijlstra
2013-09-16 10:25         ` Ingo Molnar
2013-09-16 10:43           ` Peter Zijlstra
2013-09-16 16:45             ` Dave Jones
2013-09-16 16:44         ` Dave Jones
2013-09-18 11:34           ` Peter Zijlstra
2013-09-18 13:22             ` Dave Jones
2013-09-13 14:32     ` Steven Rostedt
2013-09-13 14:58       ` Peter Zijlstra
2013-09-13 11:14   ` Peter Zijlstra
2013-09-13 14:28     ` Dave Jones
2013-09-13 14:58       ` Peter Zijlstra
2013-11-19 19:18     ` tip-bot for Peter Zijlstra [this message]

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