Re: [REGRESSION from 2.6.23-rc8] (was: Re: 2.6.23-rc4-mm1 and -rc6-mm1: boot failure on HP nx6325, related to clockevents)
From: Andi Kleen
Date: Sun Sep 30 2007 - 05:58:33 EST
> > OK, this explains 2) and 3). I just looked into the code and the logic
> > vs. noapictimer on SMP is completely broken.
noapictimer really doesn't make any sense on non SMP imho with the old
timer architecture. That is why I never bothered to implement it.
It's purely a UP hack.
> ..and thanks for the explanation.
> Thanks for finding it so quickly guys. Sounds like this will be fixed
> properly in 2.6.24 with the x86 merge (which hopefully brings in the hrt
> patch too)
There is nothing really to fix currently. Clockevents changes behaviour
majorly (always using APIC timers without irq 0 backups) and that causes
problems that need new workarounds and new fixes (surprise surprise!)
That merge would probably fix a few more such "Thomas doesn't understand
the code" bugs I guess because he hacks much more on i386 than x86-64;
but if the overall result will be really better is a totally different
 Or let's call it "I trust all my time to the CPU" and no more southrbridge
aka put all eggs in one basket. Given the trends in CPU power saving that
is a quite dangerous strategy.
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