Messages in this thread | | | Date | Wed, 15 May 2013 18:51:52 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 1/3] perf, x86: Blacklist all MEM_*_RETIRED events for IVB |
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On Wed, May 15, 2013 at 04:20:46PM +0200, Stephane Eranian wrote: > Hi, > > Based on our testing, it appears the corruption occurs only > when the MEM_* events are used and only on the sibling > counter. In other words, if HT0 has MEM_* in cntr0, then > HT1 cntr0 cannot be used, otherwise whatever is there may > get corrupted.
Ah, great. That is the least horrid case :-)
> So I think we could enhance Andi's initial patch > to handle this case instead of blacklist those events. They are > very important events.
Will you take a stab at it? I suppose you'll have to make each counter have a shared resource and have the mem_*_retired events mark the resource taken.
Also, did you test what happens when you turn SMT off in the BIOS so you get double the amount of counters; do we then leak into CNTn+4 or is all well again?
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