From: David Nellans <david@nellans.org>
To: Erwan Velu <erwan@enovance.com>
Cc: "Brian L." <brianclam@gmail.com>,
"fio@vger.kernel.org" <fio@vger.kernel.org>
Subject: Re: IO scheduler
Date: Thu, 10 Oct 2013 16:18:10 -0500 [thread overview]
Message-ID: <52571992.3020607@nellans.org> (raw)
In-Reply-To: <5257158A.2050707@enovance.com>
> That's a little bit extreme but it insures the same OS & environment to
> be used over & over making all my tests much more comparable over time.
>
Thats a really good point - I guess I should also be a little more
specific about how we achieved tight reproducibility.
We used dedicated machines with identical components, a fixed point
within an OS distribution, a known bios revision/settings, and disabled
any/all frequency/power scaling. So while we ran the machines without
any special tricks, the machine configurations and OS were very
extremely locked down and identical except for a hostname.
Anytime we changed anything within the cluster configuration we
quantified the change before rolling it out cluster wide since on more
than one occasion we discovered even things like bios revisions would
substantially affect PCIe based testing.
prev parent reply other threads:[~2013-10-10 21:18 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-10 17:08 IO scheduler Brian L.
2013-10-10 20:55 ` David Nellans
2013-10-10 21:00 ` Erwan Velu
2013-10-10 21:18 ` David Nellans [this message]
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