Re: [PATCH] x86_64 add missing enter_idle() calls

From: Andi Kleen
Date: Sat Oct 21 2006 - 09:23:41 EST



> 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.

-Andi
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