I observe a problem on a relatively recent, but not the latest, head. r306752 amd64 on AMD hardware. If I run pmcstat -T -P instructions -t $pid with a pid of a busy userland process, then I shortly get a (stray) NMI. Apparently hwpmc does not recognize that NMI. Any suggestions, help, me-toos? Thank you! -- Andriy Gapon