From: Ingo Molnar <mingo@elte.hu>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] tracing/ftrace: use preempt_enable_no_resched_notrace in ring_buffer_time_stamp()
Date: Tue, 16 Dec 2008 22:20:28 +0100 [thread overview]
Message-ID: <20081216212028.GP14787@elte.hu> (raw)
In-Reply-To: <494818EA.7080807@gmail.com>
* Frederic Weisbecker <fweisbec@gmail.com> wrote:
> Impact: prevent a trace recursion
>
> After some tests with function graph tracer under x86-32, I saw some recursions
> caused by ring_buffer_time_stamp() that calls preempt_enable_no_notrace() which
> calls preempt_schedule() which is traced itself.
>
> This patch re-enables preemption without rescheduling.
>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
> ---
> kernel/trace/ring_buffer.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
applied to tip/tracing/ftrace, thanks Frederic!
Does this explain+fix the weird crashes/reboots you were seeing?
Ingo
next prev parent reply other threads:[~2008-12-16 21:20 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-16 21:08 [PATCH] tracing/ftrace: use preempt_enable_no_resched_notrace in ring_buffer_time_stamp() Frederic Weisbecker
2008-12-16 21:20 ` Ingo Molnar [this message]
2008-12-16 21:39 ` Frédéric Weisbecker
2008-12-16 21:43 ` Steven Rostedt
2008-12-16 21:48 ` Frédéric Weisbecker
2008-12-16 21:55 ` Frédéric Weisbecker
2008-12-16 21:59 ` Ingo Molnar
2008-12-16 22:53 ` Steven Rostedt
2008-12-16 21:50 ` Ingo Molnar
2008-12-16 22:38 ` Frédéric Weisbecker
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