Hi-- On Apr 7, 2011, at 10:12 AM, Andriy Gapon wrote: > what do you think about the following change? > The idea is mark TSC as the best timecounter when it's invariant and > synchronized > between cores. > Unfortunately I don't have code to auto-detect the synchronization and keep > relying on the corresponding tunable. I thought about auto-setting it for > single-package configurations, but even that information is currently not > trivial > to get out of our mp (i386/amd64) machdep code.
In theory, most machines with P-state invariant TSCs should have their counters completely synchronized, even if there are multiple packages: http://software.intel.com/en-us/forums/showthread.php?t=74798 http://www.intel.com/Assets/PDF/manual/253668.pdf ...the exception would be very large machines with multiple mainboards. Regards, -- -Chuck _______________________________________________ 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"
