Re: [patch] oprofile for ppc

[Segher Boessenkool]

Benjamin Herrenschmidt wrote:
> Beware though that some G4s have a nasty bug that prevents
> using the performance counter interrupt (and the thermal interrupt
> as well).

MPC7400 version 1.2 and lower have this problem.

 > The problem is that if any of those fall at the same
> time as the DEC interrupt, the CPU messes up it's internal
> state and you lose SRR0/SRR1, which means you can't recover
> from the exception.

But the worst that happens is that you lose that process, isn't
it?  Not all that big a problem, esp. since the window in which
this can happen is very small.

Segher