Date: Fri, 18 Dec 2009 09:06:31 +0100
From: Pavel Machek <pavel@ucw.cz>
To: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: linux-kernel@vger.kernel.org, npiggin@suse.de, akpm@osdl.org,
       jeremy@goop.org, xen-devel@lists.xensource.com,
       tmem-devel@oss.oracle.com, kurt.hackel@oracle.com,
       Russell <rusty@rustcorp.com.au>, Rik van Riel <riel@redhat.com>,
       dave.mccracken@oracle.com, linux-mm@kvack.org,
       Rusty@rcsinet15.oracle.com, sunil.mushran@oracle.com,
       Avi Kivity <avi@redhat.com>, Schwidefsky <schwidefsky@de.ibm.com>,
       Balbir Singh <balbir@linux.vnet.ibm.com>,
       Marcelo Tosatti <mtosatti@redhat.com>, alan@lxorguk.ukuu.org.uk,
       chris.mason@oracle.com
Subject: Re: Tmem [PATCH 0/5] (Take 3): Transcendent memory
Message-ID: <20091218080631.GA1374@ucw.cz>
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Hi!

> Performance is difficult to quantify because some benchmarks respond
> very favorably to increases in memory and tmem may do quite well on
> those, depending on how much tmem is available which may vary widely
> and dynamically, depending on conditions completely outside of the
> system being measured.  Ideas on how best to provide useful metrics
> would be appreciated.

So... take 1GB system, run your favourite benchmark. Then reserve
512MB for tmem, rerun your benchmark, then run the system with
512MB/512MB swap, rerun the benchmark?

Tune the sizes so that first to last run differ by 100% or so, and see
how much first and second differs? If it is in 1% range, you are
probably doing good...?
								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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