Improving IPMI performance under load
From: Martin Wilck
Date: Tue Mar 24 2009 - 05:30:27 EST
Hi Corey,
yesterday I posted some results about the IPMI performance under CPU
load, which can be up to 25 times slower than in an idle system. I think
it might be worthwhile to try to improve that behavior as well.
I made a variation of my patch which introduces a second parameter
(kipmid_min_busy) that causes kipmid not to call schedule() for a
certain amount of time. Thus if there's IPMI traffic pending, kipmid
will busy-loop for kipmid_min_busy seconds, then starting to schedule()
in each loop as it does now, and finally go to sleep when
kipmid_max_busy is reached. At the same time, I changed the nice value
of kipmid from 19 to 0.
With this patch and e.g. min_busy=100 and max_busy=200, there is no
noticeable difference any more between IPMI performance with and without
CPU load.
The patch + results still need cleanup, therefore I am not sending it
right now. Just wanted to hear what you think.
Martin
--
Martin Wilck
PRIMERGY System Software Engineer
FSC IP ESP DEV 6
Fujitsu Siemens Computers GmbH
Heinz-Nixdorf-Ring 1
33106 Paderborn
Germany
Tel: ++49 5251 525 2796
Fax: ++49 5251 525 2820
Email: mailto:martin.wilck@xxxxxxxxxxxxxxxxxxx
Internet: http://www.fujitsu-siemens.com
Company Details: http://www.fujitsu-siemens.com/imprint.html
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