From: Rick Jones <rick.jones2@hp.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: sedat.dilek@gmail.com, netdev@vger.kernel.org,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH net-next] softirq: reduce latencies
Date: Thu, 03 Jan 2013 11:41:35 -0800 [thread overview]
Message-ID: <50E5DEEF.2080009@hp.com> (raw)
In-Reply-To: <1357219919.21409.24519.camel@edumazet-glaptop>
On 01/03/2013 05:31 AM, Eric Dumazet wrote:
> A common network load is to launch ~200 concurrent TCP_RR netperf
> sessions like the following
>
> netperf -H remote_host -t TCP_RR -l 1000
> And then you can launch some netperf asking P99_LATENCY results :
>
> netperf -H remote_host -t TCP_RR -- -k P99_LATENCY
In terms of netperf overhead, once you specify P99_LATENCY, you are
already in for the pound of cost but only getting the penny of output
(so to speak). While it would clutter the output, one could go ahead
and ask for the other latency stats and it won't "cost" anything more:
... -- -k
RT_LATENCY,MIN_LATENCY,MAX_LATENCY,P50_LATENCY,P90_LATENCY,P99_LATENCY,MEAN_LATENCY,STDDEV_LATENCY
Additional information about how the omni output selectors work can be
found at
http://www.netperf.org/svn/netperf2/trunk/doc/netperf.html#Omni-Output-Selection
happy benchmarking,
rick jones
BTW - you will likely see some differences between RT_LATENCY, which is
calculated from the average transactions per second, and MEAN_LATENCY,
which is calculated from the histogram of individual latencies
maintained when any of the _LATENCY outputs other than RT_LATENCY is
requested. Kudos to the folks at Google who did the extensions to the
then-existing histogram code to enable it to be used for more reasonably
accurate statistics.
next prev parent reply other threads:[~2013-01-03 19:41 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-03 13:12 [PATCH net-next] softirq: reduce latencies Sedat Dilek
2013-01-03 13:31 ` Eric Dumazet
2013-01-03 19:41 ` Rick Jones [this message]
2013-01-04 4:41 ` Eric Dumazet
2013-01-04 5:31 ` Sedat Dilek
2013-01-04 6:54 ` Eric Dumazet
2013-01-04 11:57 ` Sedat Dilek
-- strict thread matches above, loose matches on Subject: below --
2013-01-03 12:28 Eric Dumazet
2013-01-03 20:46 ` Andrew Morton
2013-01-03 22:41 ` Eric Dumazet
2013-01-04 5:16 ` Namhyung Kim
2013-01-04 6:53 ` Eric Dumazet
[not found] ` <787701357283699@web24e.yandex.ru>
2013-01-04 7:46 ` Eric Dumazet
2013-01-03 22:08 ` Ben Hutchings
2013-01-03 22:40 ` Eric Dumazet
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=50E5DEEF.2080009@hp.com \
--to=rick.jones2@hp.com \
--cc=eric.dumazet@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=sedat.dilek@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).