Re: [PATCH 1/4] perf, x86: Add Intel Nehalem/Westmere uncore pmu

[Andi Kleen]

>
>>   But it's not strictly required I would say,
>> 44(?) bits are probably enough for near all use cases.
>
> 44bits is in the hours range for pure cycle counts, which is so-so. I
> bet you're going to be very annoyed when you find your counters are
> wrecked after your 5 hour test run finishes.

For these kinds of long running measurements you usually care about
ratios, not absolutes. Some infrequent wrapping should not substantially
change.
those.

-Andi

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