Re: [PATCH] powerpc: perf: Handle events that raise an exception without overflowing

On Wed, 2011-03-16 at 13:50 +0100, Ingo Molnar wrote:

* Anton Blanchard [off-list ref] wrote:

quoted

Events on POWER7 can roll back if a speculative event doesn't
eventually complete. Unfortunately in some rare cases they will
raise a performance monitor exception. We need to catch this to
ensure we reset the PMC. In all cases the PMC will be 256 or less
cycles from overflow.

Signed-off-by: Anton Blanchard <redacted>
Cc: stable@kernel.org
---

I would prefer not to add the PVR check, but I think we want to limit
this workaround to POWER7. Would a cpu feature be preferable?

There was no objection from the PowerPC folks so i'll send this fix Linuswards, ok?

Ah yes.

Ack.

Cheers,
Ben.