Date: Fri, 13 Jul 2012 14:02:05 +0000 (UTC) From: Davide Italiano <davide@FreeBSD.org> To: src-committers@freebsd.org, svn-src-projects@freebsd.org Subject: svn commit: r238425 - in projects/calloutng/sys: kern sys Message-ID: <201207131402.q6DE25Qk072736@svn.freebsd.org>
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Author: davide Date: Fri Jul 13 14:02:05 2012 New Revision: 238425 URL: http://svn.freebsd.org/changeset/base/238425 Log: Fix an issue related to old periodic timers. The code in kern_clocksource.c uses interrupt to keep track of time, and this time may not match with binuptime(). In order to address such incoerency, switch periodic timers to binuptime(). While here, modify callout_process() so that it takes present time as argument avoiding to call binuptime() twice even though it's not strictly needed. Reviewed by: mav Modified: projects/calloutng/sys/kern/kern_clock.c projects/calloutng/sys/kern/kern_clocksource.c projects/calloutng/sys/kern/kern_timeout.c projects/calloutng/sys/sys/callout.h Modified: projects/calloutng/sys/kern/kern_clock.c ============================================================================== --- projects/calloutng/sys/kern/kern_clock.c Fri Jul 13 13:24:33 2012 (r238424) +++ projects/calloutng/sys/kern/kern_clock.c Fri Jul 13 14:02:05 2012 (r238425) @@ -425,6 +425,7 @@ initclocks(dummy) void hardclock_cpu(int usermode) { + struct bintime now; struct pstats *pstats; struct thread *td = curthread; struct proc *p = td->td_proc; @@ -459,7 +460,8 @@ hardclock_cpu(int usermode) if (td->td_intr_frame != NULL) PMC_SOFT_CALL_TF( , , clock, hard, td->td_intr_frame); #endif - callout_process(); + binuptime(&now); + callout_process(&now); } /* Modified: projects/calloutng/sys/kern/kern_clocksource.c ============================================================================== --- projects/calloutng/sys/kern/kern_clocksource.c Fri Jul 13 13:24:33 2012 (r238424) +++ projects/calloutng/sys/kern/kern_clocksource.c Fri Jul 13 14:02:05 2012 (r238425) @@ -239,7 +239,7 @@ handleevents(struct bintime *now, int fa if (bintime_cmp(now, &state->nextcall, >=) && (state->nextcall.sec != -1)) { state->nextcall.sec = -1; - callout_process(); + callout_process(now); } #ifdef KDTRACE_HOOKS @@ -363,13 +363,12 @@ timercb(struct eventtimer *et, void *arg next = &state->nexttick; } else next = &nexttick; - if (periodic) { - now = *next; /* Ex-next tick time becomes present time. */ + binuptime(&now); + if (periodic) { + *next = now; bintime_add(next, &timerperiod); /* Next tick in 1 period. */ - } else { - binuptime(&now); /* Get present time from hardware. */ - next->sec = -1; /* Next tick is not scheduled yet. */ - } + } else + next->sec = -1; /* Next tick is not scheduled yet. */ state->now = now; CTR4(KTR_SPARE2, "intr at %d: now %d.%08x%08x", curcpu, (int)(now.sec), (u_int)(now.frac >> 32), @@ -720,11 +719,7 @@ cpu_initclocks_ap(void) state = DPCPU_PTR(timerstate); binuptime(&now); ET_HW_LOCK(state); - if ((timer->et_flags & ET_FLAGS_PERCPU) == 0 && periodic) { - state->now = nexttick; - bintime_sub(&state->now, &timerperiod); - } else - state->now = now; + state->now = now; hardclock_sync(curcpu); handleevents(&state->now, 2); if (timer->et_flags & ET_FLAGS_PERCPU) Modified: projects/calloutng/sys/kern/kern_timeout.c ============================================================================== --- projects/calloutng/sys/kern/kern_timeout.c Fri Jul 13 13:24:33 2012 (r238424) +++ projects/calloutng/sys/kern/kern_timeout.c Fri Jul 13 14:02:05 2012 (r238425) @@ -349,9 +349,9 @@ get_bucket(struct bintime *bt) } void -callout_process(void) +callout_process(struct bintime *now) { - struct bintime max, min, next, now, tmp_max, tmp_min; + struct bintime max, min, next, tmp_max, tmp_min; struct callout *tmp; struct callout_cpu *cc; struct callout_tailq *sc; @@ -364,10 +364,9 @@ callout_process(void) need_softclock = 0; cc = CC_SELF(); mtx_lock_spin_flags(&cc->cc_lock, MTX_QUIET); - binuptime(&now); cpu = curcpu; first = callout_hash(&cc->cc_lastscan); - last = callout_hash(&now); + last = callout_hash(now); /* * Check if we wrapped around the entire wheel from the last scan. * In case, we need to scan entirely the wheel for pending callouts. @@ -380,7 +379,7 @@ callout_process(void) TAILQ_FOREACH(tmp, sc, c_links.tqe) { next = tmp->c_time; bintime_sub(&next, &tmp->c_precision); - if (bintime_cmp(&next, &now, <=)) { + if (bintime_cmp(&next, now, <=)) { /* * Consumer told us the callout may be run * directly from hardware interrupt context. @@ -445,7 +444,7 @@ callout_process(void) if (max.sec == TIME_T_MAX) { next.sec = 0; next.frac = (uint64_t)1 << (64 - 2); - bintime_add(&next, &now); + bintime_add(&next, now); } else { /* * Now that we found something to aggregate, schedule an @@ -461,7 +460,7 @@ callout_process(void) cc->cc_firstevent = next; if (callout_new_inserted != NULL) (*callout_new_inserted)(cpu, next); - cc->cc_lastscan = now; + cc->cc_lastscan = *now; mtx_unlock_spin_flags(&cc->cc_lock, MTX_QUIET); /* * swi_sched acquires the thread lock, so we don't want to call it Modified: projects/calloutng/sys/sys/callout.h ============================================================================== --- projects/calloutng/sys/sys/callout.h Fri Jul 13 13:24:33 2012 (r238424) +++ projects/calloutng/sys/sys/callout.h Fri Jul 13 14:02:05 2012 (r238425) @@ -113,7 +113,7 @@ int callout_schedule_on(struct callout * callout_schedule_on((c), (on_tick), PCPU_GET(cpuid)) #define callout_stop(c) _callout_stop_safe(c, 0) int _callout_stop_safe(struct callout *, int); -void callout_process(void); +void callout_process(struct bintime *); extern void (*callout_new_inserted)(int cpu, struct bintime bt); #endif
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