From: Milian Wolff <milian.wolff@kdab.com>
To: Taeung Song <treeze.taeung@gmail.com>
Cc: perf group <linux-perf-users@vger.kernel.org>
Subject: Re: What unit is used by "period" for sleep time profiling?
Date: Tue, 23 Feb 2016 20:29:34 +0100 [thread overview]
Message-ID: <2598992.ACoTVoLDcM@milian-kdab2> (raw)
In-Reply-To: <56CC9AB6.1080902@gmail.com>
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On Wednesday, February 24, 2016 2:45:26 AM CET Taeung Song wrote:
> Hi, Milian
>
> On 02/23/2016 11:08 PM, Milian Wolff wrote:
> > Hey all,
> >
> > following the "profiling sleep times" steps on the perf wiki at [1], we
> > can
> > get some "Period" numbers. The wiki e.g. shows a number of "502408738".
>
> AFAIK,
> When it comes to perf, "Period" means the number of occurrences
> of an event, not the number of timer ticks.
>
> The period is raw number of event count of sample.
>
> Perf can collect partial samples from a lot of event
> information(who/how much/when/etc.) or get all available samples.
> (of course, there are some limits using actual hardware counters)
>
> For example,
>
> # perf record -e cycles -c 1000 sleep 5
>
> As above, if -c option is used,
> perf-record can collect a sample every 1000 occurrences
> of event 'cycles' for 5 seconds. (sampling period = 1000)
I know, but this does not apply to the sleep time profiling, does it?
--
Milian Wolff | milian.wolff@kdab.com | Software Engineer
KDAB (Deutschland) GmbH&Co KG, a KDAB Group company
Tel: +49-30-521325470
KDAB - The Qt Experts
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prev parent reply other threads:[~2016-02-23 19:29 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-23 14:08 What unit is used by "period" for sleep time profiling? Milian Wolff
2016-02-23 17:45 ` Taeung Song
2016-02-23 19:29 ` Milian Wolff [this message]
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