Messages in this thread | | | From | Vince Weaver <> | Date | Wed, 17 Aug 2016 00:53:01 -0400 (EDT) | Subject | perf: rdpmc and PERF_EVENT_IOC_RESET |
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Hello
so using rdpmc() and the mmap page to do fast perf_event reads seems to interact poorly with the PERF_EVENT_IOC_RESET ioctl.
From what I can tell, on reset event->count is set to zero, but event->hw.prev_count is not, so the userpg->offset field ends up negative and weird things happen.
Shout reset just not be called if you are using the rdpmc() interface?
Vince
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