on 18/11/2010 05:53 George Neville-Neil said the following: > > On Nov 16, 2010, at 09:37 , Andriy Gapon wrote: > >> >> Many modern processors provide APERF and MPERF MSRs which allow to easily and >> reliable calculate average CPU performance level over some interval of time. >> This also allows to notice things like performance boost, which is generally >> hidden from software. >> What would be a proper place to add code that would measure APERF/MPERF >> ratio? >> When should trigger such a measurement and over what interval? >> Ideas? > > Can you point me at documentation for this? This sounds a lot like > hwpmc(4) and I wonder if we can make these available in the same way.
Actually it feels more cpufreq-ish to me. This feature is documented in, e.g., Intel Software Developer's Manual volume 3A, section 14.2 P-STATE HARDWARE COORDINATION. -- Andriy Gapon _______________________________________________ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
