From: puvi <r.puvichakravarthy@gmail.com>
To: fio <fio@vger.kernel.org>
Subject: Understanding cpu% in fio
Date: Tue, 25 Feb 2014 22:51:35 +0530 [thread overview]
Message-ID: <CAMYQYmqi-Re5oU9JSX1sm=E5f=ucrwRuf1BRmdo5y+JkhEouhw@mail.gmail.com> (raw)
Hi All,
Could you kindly help me understand the cpu% reported in FIO output.
I'm using a dat file with the following global parameters.
[global]
buffered=1
bs=128k
iodepth=16
numjobs=1
group_reporting=1
size=2000m
rw=read
runtime=180
time_based
and in the result I get something like this
cpu : usr=0.08%, sys=98.63%, ctx=46607, majf=0, minf=768
and I monitor the system level utilization using vmstat and they
point to different values ( lesser values).
Looking at the code I see that fio does cpu% as cpu_time( from
rusage) / total elapsed time. In the above case I have 128 jobfiles
running. Does fio add the cpu_time of all threads and then divide by
elapsed time ( ~180s) ? Kindly correct me if I'm wrong.
Thanks.
~Puvi
reply other threads:[~2014-02-25 17:21 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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='CAMYQYmqi-Re5oU9JSX1sm=E5f=ucrwRuf1BRmdo5y+JkhEouhw@mail.gmail.com' \
--to=r.puvichakravarthy@gmail.com \
--cc=fio@vger.kernel.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.