upstream/opnsense-src
1
0
Fork 0
mirror of https://github.com/opnsense/src.git synced 2026-03-28 13:43:12 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

Make kevent(2) periodic timer events more reliably periodic. The event

Browse source 
callout is now scheduled using the C_ABSOLUTE flag, and the absolute time
of each event is calculated as the time the previous event was scheduled
for plus the interval.  This ensures that latency in processing a given
event doesn't perturb the arrival time of any subsequent events.

Reviewed by:	jhb
This commit is contained in:
Ian Lepore 2014-10-04 15:59:15 +00:00
parent 4bb264ae15
commit 41e8f7efbe
2 changed files with 10 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

14
sys/kern/kern_event.c
View file

@ -569,9 +569,10 @@ filt_timerexpire(void *knx)
if ((kn->kn_flags & EV_ONESHOT) != EV_ONESHOT) {
calloutp = (struct callout *)kn->kn_hook;
callout_reset_sbt_on(calloutp,
timer2sbintime(kn->kn_sdata, kn->kn_sfflags), 0,
filt_timerexpire, kn, PCPU_GET(cpuid), 0);
*kn->kn_ptr.p_nexttime += timer2sbintime(kn->kn_sdata,
kn->kn_sfflags);
callout_reset_sbt_on(calloutp, *kn->kn_ptr.p_nexttime, 0,
filt_timerexpire, kn, PCPU_GET(cpuid), C_ABSOLUTE);
}
}
@ -607,11 +608,13 @@ filt_timerattach(struct knote *kn)
kn->kn_flags |= EV_CLEAR; /* automatically set */
kn->kn_status &= ~KN_DETACHED; /* knlist_add clears it */
kn->kn_ptr.p_nexttime = malloc(sizeof(sbintime_t), M_KQUEUE, M_WAITOK);
calloutp = malloc(sizeof(*calloutp), M_KQUEUE, M_WAITOK);
callout_init(calloutp, CALLOUT_MPSAFE);
kn->kn_hook = calloutp;
callout_reset_sbt_on(calloutp, to, 0,
filt_timerexpire, kn, PCPU_GET(cpuid), 0);
*kn->kn_ptr.p_nexttime = to + sbinuptime();
callout_reset_sbt_on(calloutp, *kn->kn_ptr.p_nexttime, 0,
filt_timerexpire, kn, PCPU_GET(cpuid), C_ABSOLUTE);
return (0);
}
@ -625,6 +628,7 @@ filt_timerdetach(struct knote *kn)
calloutp = (struct callout *)kn->kn_hook;
callout_drain(calloutp);
free(calloutp, M_KQUEUE);
free(kn->kn_ptr.p_nexttime, M_KQUEUE);
old = atomic_fetch_sub_explicit(&kq_ncallouts, 1, memory_order_relaxed);
KASSERT(old > 0, ("Number of callouts cannot become negative"));
kn->kn_status |= KN_DETACHED; /* knlist_remove sets it */

1
sys/sys/event.h
View file

@ -221,6 +221,7 @@ struct knote {
struct proc *p_proc; /* proc pointer */
struct aiocblist *p_aio; /* AIO job pointer */
struct aioliojob *p_lio; /* LIO job pointer */
sbintime_t *p_nexttime; /* next timer event fires at */
void *p_v; /* generic other pointer */
} kn_ptr;
struct filterops *kn_fop;