Messages in this thread | | | Date | Tue, 24 Oct 2006 03:00:32 -0700 | From | Stephane Eranian <> | Subject | Re: [PATCH] x86_64 add missing enter_idle() calls |
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Andi,
On Sat, Oct 21, 2006 at 03:22:53PM +0200, Andi Kleen wrote: > > > I finally found the culprit for this. The current code is wrong for the > > simple reason that the cpu_idle() function is NOT always the lowest level > > idle loop function. For enter_idle()/__exit_idle() to work correctly they > > must be placed in the lowest-level idle loop. The cpu_idle() eventually ends > > up in the idle() function, but this one may have a loop in it! This is the > > case when idle()=cpu_default_idle() and idle()=poll_idle(), for instance. > > Ah now I remember - i had actually fixed that (it was the cleanup-idle-loops > patch) that moved the loops one level up. But then I disabled the patch > at the request of Andrew because it conflicted with some ACPI idle changes. > > I'll readd it for .20, then things should be ok. >
Ok, that's good. In the meantime, I need to produce the i386 equivalent. Given how poll_idle() works (tight loop), I don't think we can just add enter_idle()/exit_idle() around the loop, we also need to cover the interrupt handlers, because that is the only place where we can catch activity considered useful.
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