Date: Sun, 1 Mar 2009 07:46:23 -0800 (PST) From: Barney Cordoba <barney_cordoba@yahoo.com> To: current@freebsd.org Subject: Re: CPU usage inaccuracy for taskqueue Message-ID: <259584.14857.qm@web63903.mail.re1.yahoo.com>
next in thread | raw e-mail | index | archive | help
--- On Sun, 3/1/09, Barney Cordoba <barney_cordoba@yahoo.com> wrote:
> From: Barney Cordoba <barney_cordoba@yahoo.com>
> Subject: CPU usage inaccuracy for taskqueue
> To: current@freebsd.org
> Date: Sunday, March 1, 2009, 10:22 AM
> I've been playing with the ige driver and as a test
> shifted the entire
> receive load to a task instead of doing it in the msix_rx
> routine by simply
> launching a receive task whenever an interrupt is
> generated. When doing so
> and applying a moderate load, top readings show:
>
> PID USERNAME THR PRI NICE SIZE RES STATE C TIME
> WCPU COMMAND 11 root 1 171 ki31 0K 8K RUN
> 3 6:31 100.00% idle: cpu3 12 root 1 171 ki31
> 0K 8K CPU2 2 6:30 100.00% idle: cpu2 13 root
> 1 171 ki31 0K 8K CPU1 1 6:29 100.00% idle: cpu1
> 14 root 1 171 ki31 0K 8K CPU0 0 6:23
> 99.17% idle: cpu0
> 42 root 1 -68 - 0K 8K - 0 0:07
> 7.47% igb1 taskq
>
> clearly the cpu idle thread values aren't correct. This
> is the case in
> both 7.0 and 7.1. Since the point of my testing is to
> experiment with
> schemes for spreading loads better, I'm not able to
> learn anything with
> the lack of usable feedback. Is there a simple fix?
>
> Barney
Sorry for the ugly post. It looks ok in Yahoo and then gets all jumbled.
The gist of the top output:
100.00% idle: cpu3
100.00% idle: cpu2
100.00% idle: cpu1
99.17% idle: cpu0
7.47% igb1 taskq
The task is show 7.5% usage and < 1% usage is shown by the cpu idle
threads.
Barney
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?259584.14857.qm>