Re: [patch] oprofile for ppc

From: Segher Boessenkool (segher@koffie.nl)
Date: Sun Mar 09 2003 - 22:50:43 EST


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

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Sat Mar 15 2003 - 22:00:20 EST