From: Manuel Selva <selva.manuel@gmail.com>
To: Milian Wolff <milian.wolff@kdab.com>, linux-perf-users@vger.kernel.org
Subject: Re: Does perf randomize the sampling period?
Date: Wed, 9 Sep 2015 17:16:12 +0200 [thread overview]
Message-ID: <55F04D3C.60908@gmail.com> (raw)
In-Reply-To: <1769534.mDAXVEGQ5L@milian-kdab2>
Regarding perf mem record on Intel platforms, I think that the sampling
randomization is ensured by the hardware.
----
Manu
On 09/09/2015 05:11 PM, Milian Wolff wrote:
> Hey all,
>
> does perf randomize its sampling intervals/period to prevent pattern effects?
> I found https://lkml.org/lkml/2010/3/4/51 but neither the man page on perf
> record says anything on that matter, nor does the perf wiki say it's
> supported:
>
> https://perf.wiki.kernel.org/index.php/Tutorial#Period_and_rate
>
>> There is currently no support for sampling period randomization.
>
> So is it supported, or not? If it is supported, how do I enable it? Or is this
> enabled by default?
>
> If it is not supported, why so? Is it not important to have?
>
> Thanks
>
next prev parent reply other threads:[~2015-09-09 15:16 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-09 15:11 Does perf randomize the sampling period? Milian Wolff
2015-09-09 15:16 ` Manuel Selva [this message]
2015-09-09 15:24 ` Andreas Hollmann
2015-09-10 15:48 ` Andi Kleen
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