What’s the motivation for using more timehands? On Mon, Sep 9, 2019 at 04:30 Konstantin Belousov <k...@freebsd.org> wrote:
> Author: kib > Date: Mon Sep 9 11:29:58 2019 > New Revision: 352059 > URL: https://svnweb.freebsd.org/changeset/base/352059 > > Log: > Make timehands count selectable at boottime. > > Tested by: O'Connor, Daniel <dar...@dons.net.au> > Sponsored by: The FreeBSD Foundation > MFC after: 1 week > Differential revision: https://reviews.freebsd.org/D21563 > > Modified: > head/sys/kern/kern_tc.c > > Modified: head/sys/kern/kern_tc.c > > ============================================================================== > --- head/sys/kern/kern_tc.c Mon Sep 9 11:22:38 2019 (r352058) > +++ head/sys/kern/kern_tc.c Mon Sep 9 11:29:58 2019 (r352059) > @@ -83,19 +83,16 @@ struct timehands { > struct timehands *th_next; > }; > > -static struct timehands th0; > -static struct timehands th1 = { > - .th_next = &th0 > -}; > -static struct timehands th0 = { > +static struct timehands ths[16] = { > + [0] = { > .th_counter = &dummy_timecounter, > .th_scale = (uint64_t)-1 / 1000000, > .th_offset = { .sec = 1 }, > .th_generation = 1, > - .th_next = &th1 > + }, > }; > > -static struct timehands *volatile timehands = &th0; > +static struct timehands *volatile timehands = &ths[0]; > struct timecounter *timecounter = &dummy_timecounter; > static struct timecounter *timecounters = &dummy_timecounter; > > @@ -115,6 +112,10 @@ static int timestepwarnings; > SYSCTL_INT(_kern_timecounter, OID_AUTO, stepwarnings, CTLFLAG_RW, > ×tepwarnings, 0, "Log time steps"); > > +static int timehands_count = 2; > +SYSCTL_INT(_kern_timecounter, OID_AUTO, timehands_count, CTLFLAG_RDTUN, > + &timehands_count, 0, "Count of timehands in rotation"); > + > struct bintime bt_timethreshold; > struct bintime bt_tickthreshold; > sbintime_t sbt_timethreshold; > @@ -1960,8 +1961,9 @@ done: > static void > inittimecounter(void *dummy) > { > + struct timehands *thp; > u_int p; > - int tick_rate; > + int i, tick_rate; > > /* > * Set the initial timeout to > @@ -1987,6 +1989,16 @@ inittimecounter(void *dummy) > #ifdef FFCLOCK > ffclock_init(); > #endif > + > + /* Set up the requested number of timehands. */ > + if (timehands_count < 1) > + timehands_count = 1; > + if (timehands_count > nitems(ths)) > + timehands_count = nitems(ths); > + for (i = 1, thp = &ths[0]; i < timehands_count; thp = &ths[i++]) > + thp->th_next = &ths[i]; > + thp->th_next = &ths[0]; > + > /* warm up new timecounter (again) and get rolling. */ > (void)timecounter->tc_get_timecount(timecounter); > (void)timecounter->tc_get_timecount(timecounter); > > _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"