perf_counter: resetting a event counter

From: Corey Ashford
Date: Mon May 04 2009 - 18:15:31 EST


Hi,

In implementing the PAPI_reset function, whose purpose is to reset all of the counters in an event set, I found that [it appears] there is no straight-forward way to implement this function using "Performance Couunters for Linux". My current implementation just closes the counters and reopens them again. This is not a elegant solution, nor is the other alternative that occurred to me: maintain a "virtual" counter in user space, maintained using a base count, which is subtracted off of the current perf_counter value of a particular counter.

Is there a way that I missed to reset an event counter? If not, I'd like to request that a new ioctl command be added to support this ability.

Thanks for your consideration,

- Corey

Corey Ashford
Software Engineer
IBM Linux Technology Center, Linux Toolchain
Beaverton, OR
503-578-3507
cjashfor@xxxxxxxxxx

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