From: Jens Axboe <axboe@kernel.dk>
To: Hoppetauet <hoppetauet@gmail.com>
Cc: fio@vger.kernel.org
Subject: Re: Completion and submission latency
Date: Tue, 10 Apr 2012 14:39:49 +0200 [thread overview]
Message-ID: <4F842A15.9040808@kernel.dk> (raw)
In-Reply-To: <4F8422AA.9020005@gmail.com>
On 04/10/2012 02:08 PM, Hoppetauet wrote:
> Hi
>
> I was wondering about the completion latencies. I have been doing some virtual machine testing, and would like some help about what the values mean.
>
> 3;2.0.6;seqwrite;0;0;0;0;0;0;0;0;0.000000;0.000000;0;0;0.000000;0.000000;1.00%=0;5.00%=0;10.00%=0;20.00%=0;30.00%=0;40.00%=0;50.00%=0;60.00%=0;70.00%=0;80.00%=0;90.00%=0;95.00%=0;99.00%=0;99.50%=0;99.90%=0;99.95%=0;99.99%=0;0%=0;0%=0;0%=0;0;0;0.000000;0.000000;0;0;0.000000%;0.000000;0.000000;4194304;17426;4254;246466;0;0;0.000000;0.000000;3;5439652;228.431381;20540.522574;1.00%=4;5.00%=4;10.00%=5;20.00%=5;30.00%=5;40.00%=6;50.00%=6;60.00%=6;70.00%=6;80.00%=7;90.00%=9;95.00%=15;99.00%=25;99.50%=59;99.90%=548;99.95%=3664;99.99%=325632;0%=0;0%=0;0%=0;3;5439652;228.905854;20540.525416;0;162531;100.000000%;30172.429268;37422.864723;2.337414%;3.129483%;6751;1;20;100.0%;0.0%;0.0%;0.0%;0.0%;0.0%;0.0%;0.00%;0.38%;91.44%;6.62%;0.94%;0.27%;0.05%;0.20%;0.02%;0.01%;0.03%;0.01%;0.01%;0.01%;0.01%;0.01%;0.02%;0.01%;0.01%;0.01%;0.01%;0.01%;vda;77;10364;0;12806;4900;19896664;19973372;99.30%
>
> This is one of my test runs. The completion latency stats are as follows:
> min: 3
> max: 5439652
> avg: 228.431381
> std: 20540.522574
>
> Does this mean that the maximum amount of time it takes to write 4KB
> is 5.4 seconds? Are the values in microseconds or milliseconds (it's
> microseconds right)? Thanks
They are in microseconds, so yes that'd be 5.43s for the slowest of
them.
--
Jens Axboe
prev parent reply other threads:[~2012-04-10 12:41 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-10 12:08 Completion and submission latency Hoppetauet
2012-04-10 12:39 ` Jens Axboe [this message]
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