Messages in this thread | | | Date | Mon, 10 Nov 2014 22:08:21 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v3 10/11] perf/x86/intel: Perform rotation on Intel CQM RMIDs |
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On Mon, Nov 10, 2014 at 08:56:53PM +0000, Matt Fleming wrote: > > Should we initialize that to a finite value? Surely results are absolute > > crap if we do indeed reach that max? > > I don't think we'll ever reach that max, it'll bottom out once it > reaches the size of the LLC, since the pathological case is that the > RMID you're currently trying to stabilize is used to tag every line in > the LLC.
Sure, LLC size is the 'same'. Makes the entire ordeal rather pointless.
> Not sure what a reasonable finite value would be here though? 10% of the > LLC size?
Can you ask the same Oracle that provided the magic 250 ms? Both are magic/random numbers. 10% sounds rather large, but who knows.
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