Messages in this thread | | | Subject | Re: Problem: Load average of 6, no I/O, 25% idle time. Why? | From | Peter Zijlstra <> | Date | Sat, 19 Jul 2008 11:18:16 +0200 |
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On Fri, 2008-07-18 at 18:12 -0400, Timothy Normand Miller wrote: > On Fri, Jul 18, 2008 at 9:28 AM, Peter Zijlstra <peterz@infradead.org> wrote: > > On Fri, 2008-07-18 at 08:49 -0400, Timothy Normand Miller wrote: > >> I have a four processor box, running three compute loads. The kernel > >> I'm running is 2.6.25-gentoo-r5. > >> > >> One process has four threads, and it's niced to 19. > >> Another process has one thread and is niced to -10 > >> The last process has one thread and is niced to 0 > >> > >> One processor is always idle. > >> > >> If I change either the 0 to a -10 or the -10 to a zero, then all four > >> cores are properly utilized. > > Interesting corollary: If the only thing running is the one nice=19, > four-thread process, then there's about 4% idle time. I have to raise > the priority to get the idle time to go away. Since when do active > processes yield to idle time?
They shouldn't... I'm suspecting it might be due to some form of priority inversion or some such thing.
> Two of my three loads are finished, so when this last one is done, > I'll try 2.6.26. Was something like this actively discussed and fixed > between 2.6.25 and 2.6.26?
Not much, but it has seen drastic change post .26. So if you could also try Linus' latest -git that would be good.
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