On Friday 03 December 2010 12:26 pm, Andriy Gapon wrote: > FreeBSD uses cpu_ticks [function pointer] in a few places for a few > things like process CPU time accounting. On x86 cpu_ticks always > points to rdtsc. If TSC is not invariant that leads to incorrect > accounting of "CPU ticks". The code pretends to try to handle > changing cpufreq levels, but does that incorrectly.
Arg... Probably it is my fault. :-( > I think that we could use a selected timecounter instead of "raw" > TSC if the latter is not invariant. In this case cpu_ticks calls > would be slightly costlier, but always correct. > > The change is quite trivial: > http://people.freebsd.org/~avg/tsc-cputicker.diff > > What do you think? Why don't we just fix it properly? > P.S. it's probably a good idea to merge i386 and amd64 tsc.c files > into a common x86 version, which would be the same as i386 version, > which seems to be generic enough. Agreed. Thanks, Jung-uk Kim _______________________________________________ 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"
