Re: [PATCH][2.6.9-rc2-mm3] perfctr ppc32 preliminary interruptsupport

[Benjamin Herrenschmidt]

On Tue, 2004-09-28 at 06:05, Albert Cahalan wrote:
> Benjamin Herrenschmidt writes:
> 
> > Be careful that some G4's have a bug which can cause a
> > perf monitor interrupt to crash your kernel :( Basically, the
> > problem is if any of TAU or PerfMon interrupt happens at the
> > same time as a DEC interrupt, some revs of the CPU can get
> > confused and lose the previous exception state.
> 
> Instead of excluding all these CPUs, simply put the
> clock tick on the PerfMon interrupt. There's a bit-flip
> that'll go at about 4 kHz on a system with a 100 MHz bus.
> That should do. One need not change HZ; the interrupt
> can be ignored whenever the timebase hasn't advanced
> enough to require another clock tick.

True, we can use the perfmon instead of the DEC for those

Ben.


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