Messages in this thread | | | Date | Tue, 27 Apr 2010 15:01:39 +0200 | From | Pavel Machek <> | Subject | Re: [PATCH 7/7] ondemand: Solve the big performance issue with ondemand during disk IO |
| |
Hi!
> > But I follow Eric and agree that if it costs that much, changing > > above sounds sane. > > Still, I could imagine some people might want to not raise freq on IO bound > > process activity, therefore this should get another ondemand param, similar > > to ignore_nice_load. > > > > I agree with Thomas here. Some of these assumptions on IO / FSB > performance with cpu speed do not hold true on various ARM platforms. > > Perhaps we could have a min_io_freq value? Which is the min speed for > the cpu to run at for IO bound activity. In the original patch, > min_io_freq = scaling_max_freq. For various arm devices I can happily > set min_io_freq to the lowest cpu speed that satisfies bus speeds.
'satisfies bus speeds' == minimum cpu frequency where i/o works at all
or
== minimum cpu frequency where i/o works at full speed
? Pavel
-- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
| |