Author: davide
Date: Mon Mar 4 16:55:16 2013
New Revision: 247804
URL: http://svnweb.freebsd.org/changeset/base/247804
Log:
MFcalloutng:
- Rewrite kevent() timeout implementation to allow sub-tick precision.
- Make the interval timings for EVFILT_TIMER more accurate. This also
removes an hack introduced in r238424.
Sponsored by: Google Summer of Code 2012, iXsystems inc.
Tested by: flo, marius, ian, markj, Fabian Keil
Modified:
head/sys/kern/kern_event.c
Modified: head/sys/kern/kern_event.c
==============================================================================
--- head/sys/kern/kern_event.c Mon Mar 4 16:50:01 2013 (r247803)
+++ head/sys/kern/kern_event.c Mon Mar 4 16:55:16 2013 (r247804)
@@ -517,39 +517,28 @@ knote_fork(struct knlist *list, int pid)
* XXX: EVFILT_TIMER should perhaps live in kern_time.c beside the
* interval timer support code.
*/
-static int
-timertoticks(intptr_t data)
+static __inline sbintime_t
+timer2sbintime(intptr_t data)
{
- struct timeval tv;
- int tticks;
-
- tv.tv_sec = data / 1000;
- tv.tv_usec = (data % 1000) * 1000;
- tticks = tvtohz(&tv);
- return tticks;
+ return (SBT_1MS * data);
}
static void
filt_timerexpire(void *knx)
{
- struct knote *kn = knx;
struct callout *calloutp;
+ struct knote *kn;
+ kn = knx;
kn->kn_data++;
KNOTE_ACTIVATE(kn, 0); /* XXX - handle locking */
- /*
- * timertoticks() uses tvtohz() which always adds 1 to allow
- * for the time until the next clock interrupt being strictly
- * less than 1 clock tick. We don't want that here since we
- * want to appear to be in sync with the clock interrupt even
- * when we're delayed.
- */
if ((kn->kn_flags & EV_ONESHOT) != EV_ONESHOT) {
calloutp = (struct callout *)kn->kn_hook;
- callout_reset_curcpu(calloutp, timertoticks(kn->kn_sdata) - 1,
- filt_timerexpire, kn);
+ callout_reset_sbt_on(calloutp,
+ timer2sbintime(kn->kn_sdata), 0 /* 1ms? */,
+ filt_timerexpire, kn, PCPU_GET(cpuid), 0);
}
}
@@ -573,8 +562,9 @@ filt_timerattach(struct knote *kn)
calloutp = malloc(sizeof(*calloutp), M_KQUEUE, M_WAITOK);
callout_init(calloutp, CALLOUT_MPSAFE);
kn->kn_hook = calloutp;
- callout_reset_curcpu(calloutp, timertoticks(kn->kn_sdata),
- filt_timerexpire, kn);
+ callout_reset_sbt_on(calloutp,
+ timer2sbintime(kn->kn_sdata), 0 /* 1ms? */,
+ filt_timerexpire, kn, PCPU_GET(cpuid), 0);
return (0);
}
@@ -1319,10 +1309,9 @@ kqueue_scan(struct kqueue *kq, int maxev
const struct timespec *tsp, struct kevent *keva, struct thread *td)
{
struct kevent *kevp;
- struct timeval atv, rtv, ttv;
struct knote *kn, *marker;
- int count, timeout, nkev, error, influx;
- int haskqglobal, touch;
+ sbintime_t asbt, rsbt;
+ int count, error, haskqglobal, influx, nkev, touch;
count = maxevents;
nkev = 0;
@@ -1332,24 +1321,23 @@ kqueue_scan(struct kqueue *kq, int maxev
if (maxevents == 0)
goto done_nl;
+ rsbt = 0;
if (tsp != NULL) {
- TIMESPEC_TO_TIMEVAL(&atv, tsp);
- if (itimerfix(&atv)) {
+ if (tsp->tv_sec < 0 || tsp->tv_nsec < 0 ||
+ tsp->tv_nsec > 1000000000) {
error = EINVAL;
goto done_nl;
}
- if (tsp->tv_sec == 0 && tsp->tv_nsec == 0)
- timeout = -1;
- else
- timeout = atv.tv_sec > 24 * 60 * 60 ?
- 24 * 60 * 60 * hz : tvtohz(&atv);
- getmicrouptime(&rtv);
- timevaladd(&atv, &rtv);
- } else {
- atv.tv_sec = 0;
- atv.tv_usec = 0;
- timeout = 0;
- }
+ if (timespecisset(tsp)) {
+ rsbt = tstosbt(*tsp);
+ if (TIMESEL(&asbt, rsbt))
+ asbt += tc_tick_sbt;
+ asbt += rsbt;
+ rsbt >>= tc_precexp;
+ } else
+ asbt = -1;
+ } else
+ asbt = 0;
marker = knote_alloc(1);
if (marker == NULL) {
error = ENOMEM;
@@ -1357,28 +1345,16 @@ kqueue_scan(struct kqueue *kq, int maxev
}
marker->kn_status = KN_MARKER;
KQ_LOCK(kq);
- goto start;
retry:
- if (atv.tv_sec || atv.tv_usec) {
- getmicrouptime(&rtv);
- if (timevalcmp(&rtv, &atv, >=))
- goto done;
- ttv = atv;
- timevalsub(&ttv, &rtv);
- timeout = ttv.tv_sec > 24 * 60 * 60 ?
- 24 * 60 * 60 * hz : tvtohz(&ttv);
- }
-
-start:
kevp = keva;
if (kq->kq_count == 0) {
- if (timeout < 0) {
+ if (asbt == -1) {
error = EWOULDBLOCK;
} else {
kq->kq_state |= KQ_SLEEP;
- error = msleep(kq, &kq->kq_lock, PSOCK | PCATCH,
- "kqread", timeout);
+ error = msleep_sbt(kq, &kq->kq_lock, PSOCK | PCATCH,
+ "kqread", asbt, rsbt, C_ABSOLUTE);
}
if (error == 0)
goto retry;
_______________________________________________
svn-src-head@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-head
To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
