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Date: Tue, 9 Mar 2010 10:40:04 +0800
Message-ID: <2375c9f91003081840w5419d847q8ffd8b6ce46d86fb@mail.gmail.com>
Subject: Re: 2.6.33: ftrace triggers soft lockup
From: =?UTF-8?Q?Am=C3=A9rico_Wang?= <xiyou.wangcong@gmail.com>
To: rostedt@goodmis.org
Cc: LKML <linux-kernel@vger.kernel.org>,
       Frederic Weisbecker <fweisbec@gmail.com>, Ingo Molnar <mingo@elte.hu>
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On Mon, Mar 8, 2010 at 10:31 AM, Américo Wang <xiyou.wangcong@gmail.com> wrote:
> On Fri, Mar 5, 2010 at 11:06 PM, Steven Rostedt <rostedt@goodmis.org> wrote:
>>
>> Now some things you can do to help performance. One is not to trace
>> functions that are known to have a high hit rate. You can do this with
>> the set_ftrace_notrace file, or add "ftrace_notrace=func1,func2,func3"
>> to the command line where func1,func2,func3 are the functions you do not
>> want to trace. This just adds these by default to the set_ftrace_notrace
>> and can be removed at runtime.
>>
>>
>> The functions I commonly write to are:
>>
>> echo '*spin_lock*' '*spin_unlock*' '*spin_try*' '*rcu_read*' > set_ftace_notrace
>>
>> since these functions are hit quite intensively, by not tracing them it
>> helps a bit with performance.
>
> I will try this now.
>

Unfortunately, this doesn't help.

What is worse, I got another soft lockup, although I already turned LOCKDEP off.


Thanks.