From: Rick Jones <rick.jones2@hp•com>
To: Herbert Xu <herbert@gondor•apana.org.au>
Cc: Evgeniy Polyakov <johnpol@2ka•mipt.ru>,
netdev@vger•kernel.org,
Christoph Lameter <cl@linux-foundation•org>,
Mel Gorman <mel@csn•ul.ie>, David Miller <davem@davemloft•net>,
Lennert Buytenhek <buytenh@marvell•com>
Subject: Re: Patch for tbench regression.
Date: Mon, 29 Sep 2008 10:07:12 -0700 [thread overview]
Message-ID: <48E10B40.4000205@hp.com> (raw)
In-Reply-To: <20080929095126.GA25371@gondor.apana.org.au>
Sigh - email reading timing.... anyway
> It seems that netperf is issuing 16384-byte writes and as such
> we're sending the packets out immediately so TSO doesn't get a
> chance to merge the data. Running netperf with -m 65536 makes
> TSO beat non-TSO by 6293Mb/s to 4761Mb/s.
By default, netperf's TCP_STREAM test will use whatever
getsockopt(SO_SNDBUF) reports just after the data socket is created.
The choice was completely arbitrary and burried deep in the history of
netperf.
For evaluating changes, it would probably be a good idea to test a
number of settings for the test-specific -m option. Of course I have no
good idea what those values should be. There is the tcp_range_script
(might be a bit dusty today) but those values are again pretty arbitrary.
It would probably be a good idea to include the TCP_RR test.
happy benchmarking,
rick jones
As an asside - I would be interested in hearing peoples' opinions
(offline) on a future version of netperf possibly violating the
principle of least surprise and automatically including CPU utilization
if the code is running on a system which does not require calibration...
next prev parent reply other threads:[~2008-09-29 17:07 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-28 21:15 Patch for tbench regression Evgeniy Polyakov
2008-09-29 3:12 ` Herbert Xu
2008-09-29 5:36 ` Evgeniy Polyakov
2008-09-29 5:40 ` Herbert Xu
2008-09-29 5:52 ` Evgeniy Polyakov
2008-09-29 6:40 ` Herbert Xu
2008-09-29 6:45 ` Evgeniy Polyakov
2008-09-29 7:02 ` Herbert Xu
2008-09-29 7:11 ` Evgeniy Polyakov
2008-09-29 7:20 ` Herbert Xu
2008-09-29 9:43 ` Herbert Xu
2008-09-29 9:51 ` Herbert Xu
2008-09-29 17:07 ` Rick Jones [this message]
2008-09-29 10:34 ` Evgeniy Polyakov
2008-09-29 13:34 ` Christoph Lameter
2008-09-29 17:01 ` Rick Jones
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