On Tue, Mar 24, 2009 at 08:08:36AM -0500, Corey Minyard wrote: > Martin Wilck wrote: > >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. > > > Yes, that would be expected, as kipmid would never be scheduled in a > busy system, and it would just be the timer driving things. > > >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. > > > I would guess that changing the nice value is the main thing that caused > the difference. The other changes probably didn't make as big a difference. > > >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. > > > I'm ok with tuning like this, but most users are probably not going to > want this type of behavior.
I still get complaints from users who see their CPU utilization spike attributed to kipmi0 when userspace throws a lot of requests down to the controller. I've seen them want to limit kipmi0 even further, not speed it up. -- Matt Domsch Linux Technology Strategist, Dell Office of the CTO linux.dell.com & www.dell.com/linux ------------------------------------------------------------------------------ Apps built with the Adobe(R) Flex(R) framework and Flex Builder(TM) are powering Web 2.0 with engaging, cross-platform capabilities. Quickly and easily build your RIAs with Flex Builder, the Eclipse(TM)based development software that enables intelligent coding and step-through debugging. Download the free 60 day trial. http://p.sf.net/sfu/www-adobe-com _______________________________________________ Openipmi-developer mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/openipmi-developer
