From: Andi Kleen <andi@firstfloor.org>
To: Yijie Shen <henry.yijieshen@gmail.com>
Cc: linux-perf-users@vger.kernel.org
Subject: Re: toplev would hang forever when analyzing a program with PID
Date: Mon, 27 Mar 2017 13:35:38 -0700 [thread overview]
Message-ID: <874lyewj8l.fsf@firstfloor.org> (raw)
In-Reply-To: <CADGfq7zQv_3B-vYkTi8p1SQ=xcjyp3cVBAGaL=P7-gUBobbDzg@mail.gmail.com> (Yijie Shen's message of "Sun, 26 Mar 2017 22:07:44 +0800")
Yijie Shen <henry.yijieshen@gmail.com> writes:
>
>
> this would hang forever even if the process with such pid end, this
> happens whatever the pid is pointing at is, a Java process or a Linux
> tool such as top.
>
>
> Am I doing something wrong? What does the right command look like to
> analyze a program using PID?
You're using SMT, so toplev has to enable global monitoring (-a),
but that does not interact well with --pid in perf.
That's more a perf bug .
It would work in single thread mode or without SMT, or using intervals.
toplev should probably print a warning in this case.
-Andi
>
prev parent reply other threads:[~2017-03-27 20:35 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-26 14:07 toplev would hang forever when analyzing a program with PID Yijie Shen
2017-03-27 20:35 ` Andi Kleen [this message]
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