perf_counter: resetting a event counter

[Corey Ashford <cjashfor@linux.vnet.ibm.com>]

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@us.ibm.com