Messages in this thread | | | Date | Tue, 5 Jun 2007 09:10:11 +0200 | From | Ingo Molnar <> | Subject | Re: Interesting interaction between lguest and CFS |
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* Rusty Russell <rusty@rustcorp.com.au> wrote:
> This sounds like the waker process (nice 19) not getting a chance to > run. You can hack around it for the moment by changing "nice(19)" in > Documentation/lguest/lguest.c to something less aggressive.
even if the waker runs at nice+19, under CFS (which schedules deterministically) it should not be delayed by a single nice-0 task by more than ~70 msecs. That is a far cry from the 'seconds' that Matt saw - and the sched stats he sent look anomalous too. Also, i'm not able to reproduce it at all - while any nice+19 related problem should be readily reproducable on my box too. So my current take is that this is some sort of host-side CFS related problem and that the lguest host threads somehow were the first ones that managed to trigger it in some really bad way.
OTOH i do agree with your patch, that nice+19 thing is quite hacky :-)
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