From: Andi Kleen <andi@firstfloor.org>
To: Karim Yaghmour <karim.yaghmour@opersys.com>
Cc: Andi Kleen <andi@firstfloor.org>,
linux-kernel@vger.kernel.org,
Steven Rostedt <rostedt@goodmis.org>,
mingo@elte.hu
Subject: Re: Reading perf counters at ftrace trace boundaries
Date: Mon, 12 Aug 2013 03:47:48 +0200 [thread overview]
Message-ID: <20130812014748.GP19750@two.firstfloor.org> (raw)
In-Reply-To: <52083CB4.2030308@opersys.com>
> Indeed. It doesn't actually have to be at every single ftrace
> begin/exit. But possibly starting with some kind of every nth and then
> drilling down as the culprit is incrementally singled-out.
That's what normal sampling already does.
If you're worried about systematic shadow effects just randomize a bit.
-Andi
next prev parent reply other threads:[~2013-08-12 1:47 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-12 0:03 Reading perf counters at ftrace trace boundaries Karim Yaghmour
2013-08-12 1:23 ` Andi Kleen
2013-08-12 1:39 ` Karim Yaghmour
2013-08-12 1:47 ` Andi Kleen [this message]
2013-08-12 1:59 ` Karim Yaghmour
2013-08-12 2:24 ` zhangwei(Jovi)
2013-08-12 15:26 ` Karim Yaghmour
2013-08-13 7:12 ` zhangwei(Jovi)
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