On Thu, 2015-07-23 at 10:59 -0400, Brandon Allbery wrote: > On Thu, Jul 23, 2015 at 10:38 AM, <deco33...@yandex.com> wrote: > > > Is the maximum value for th_generation equal to 10 ? > > http://fxr.watson.org/fxr/source/kern/kern_tc.c?v=FREEBSD10#L77 > > > > I don't think those relate to generations. Generations change on every > clock tick; the multiple timehands structs relate to forcibly setting the > time, as opposed to the clock moving forward normally. It does appear serve > a similar purpose, since forcibly setting the time is even more "violent" > (to anything currently reading the clock) than advancing the clock on a > clock tick, since that's when other adjustments including possibly > switching the clock source will be applied. >
Ummm, no. The multiple timehands and related generation count are all about time moving forward normally, and doing so without needing mutxes or other locking primitives to obtain the current time. I think you guys need to read this... http://phk.freebsd.dk/pubs/timecounter.pdf Especially the section named "Locking, lack of..." -- Ian _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
