From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>, LKML <linux-kernel@vger.kernel.org>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Steven Rostedt <rostedt@goodmis.org>,
Li Zefan <lizf@cn.fujitsu.com>
Subject: Re: [PATCH 01/12] perf: Use tracepoint_synchronize_unregister() to flush any pending tracepoint call
Date: Mon, 2 Aug 2010 11:14:46 -0400 [thread overview]
Message-ID: <20100802151445.GA11747@Krystal> (raw)
In-Reply-To: <1280707993-6599-2-git-send-regression-fweisbec@gmail.com>
* Frederic Weisbecker (fweisbec@gmail.com) wrote:
> We use synchronize_sched() to ensure a tracepoint won't be called
> while/after we release the perf buffers it references.
>
> But the tracepoint API has its own API for that:
> tracepoint_synchronize_unregister(). Use it instead as it's
> self-explanatory and eases maintainance.
>
> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Thanks!
Mathieu
> Cc: Ingo Molnar <mingo@elte.hu>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Li Zefan <lizf@cn.fujitsu.com>
> ---
> kernel/trace/trace_event_perf.c | 6 +++---
> 1 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
> index 2375165..000e6e8 100644
> --- a/kernel/trace/trace_event_perf.c
> +++ b/kernel/trace/trace_event_perf.c
> @@ -131,10 +131,10 @@ void perf_trace_destroy(struct perf_event *p_event)
> tp_event->class->reg(tp_event, TRACE_REG_PERF_UNREGISTER);
>
> /*
> - * Ensure our callback won't be called anymore. See
> - * tracepoint_probe_unregister() and __DO_TRACE().
> + * Ensure our callback won't be called anymore. The buffers
> + * will be freed after that.
> */
> - synchronize_sched();
> + tracepoint_synchronize_unregister();
>
> free_percpu(tp_event->perf_events);
> tp_event->perf_events = NULL;
> --
> 1.6.2.3
>
--
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com
next prev parent reply other threads:[~2010-08-02 15:27 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-02 0:13 [GIT PULL] instrumentation updates Frederic Weisbecker
2010-08-02 0:13 ` [PATCH 01/12] perf: Use tracepoint_synchronize_unregister() to flush any pending tracepoint call Frederic Weisbecker
2010-08-02 15:14 ` Mathieu Desnoyers [this message]
2010-08-02 0:13 ` [PATCH 02/12] tracing: Drop cpparg() macro Frederic Weisbecker
2010-08-02 0:13 ` [PATCH 03/12] perf: New migration tool overview Frederic Weisbecker
2010-08-02 0:13 ` [PATCH 04/12] perf, sched migration: Handle ignored migrate out events Frederic Weisbecker
2010-08-02 0:13 ` [PATCH 05/12] perf, sched migration: Ignore unhandled task states Frederic Weisbecker
2010-08-02 0:13 ` [PATCH 06/12] perf, sched migration: Fix key bindings Frederic Weisbecker
2010-08-02 0:13 ` [PATCH 07/12] perf, sched migration: Parameterize cpu height and spacing Frederic Weisbecker
2010-08-02 0:13 ` [PATCH 08/12] perf, sched migration: Make it vertically scrollable Frederic Weisbecker
2010-08-02 0:13 ` [PATCH 09/12] perf, sched migration: Make the GUI class client agnostic Frederic Weisbecker
2010-08-02 0:13 ` [PATCH 10/12] perf, sched migration: Librarize the GUI class Frederic Weisbecker
2010-08-02 0:13 ` [PATCH 11/12] perf, sched migration: Librarize task states and event headers helpers Frederic Weisbecker
2010-08-02 0:13 ` [PATCH 12/12] x86,mmiotrace: Add support for tracing STOS instruction Frederic Weisbecker
2010-08-02 6:28 ` [GIT PULL] instrumentation updates Ingo Molnar
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