Messages in this thread | | | Subject | Re: [PATCH] POWER: perf_event: Skip updating kernel counters if register value shrinks | From | Benjamin Herrenschmidt <> | Date | Wed, 30 Mar 2011 08:12:45 +1100 |
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On Tue, 2011-03-29 at 10:25 -0400, Eric B Munson wrote: > Here I made the assumption that the hardware would never remove more events in > a speculative roll back than it had added. This is not a situation I > encoutered in my limited testing, so I didn't think underflow was possible. I > will send out a V2 using the signed 32 bit delta and remeber to CC stable > this time.
I'm not thinking about underflow but rollover... or that isn't possible with those counters ? IE. They don't wrap back to 0 after hitting ffffffff ?
Cheers, Ben.
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