diff options
author | mav <mav@FreeBSD.org> | 2010-09-14 08:48:06 +0000 |
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committer | mav <mav@FreeBSD.org> | 2010-09-14 08:48:06 +0000 |
commit | 6c05aa4db6d1ea20da8eca83a1214b74821b32d8 (patch) | |
tree | ad6e771c5b5091a633bf1f813ca1f742162ecb96 /sys/kern | |
parent | 5864d6e457c81a0a80b2ab3b57ee852e6f62efcb (diff) | |
download | FreeBSD-src-6c05aa4db6d1ea20da8eca83a1214b74821b32d8.zip FreeBSD-src-6c05aa4db6d1ea20da8eca83a1214b74821b32d8.tar.gz |
Make kern_tc.c provide minimum frequency of tc_ticktock() calls, required
to handle current timecounter wraps. Make kern_clocksource.c to honor that
requirement, scheduling sleeps on first CPU for no more then specified
period. Allow other CPUs to sleep up to 1/4 second (for any case).
Diffstat (limited to 'sys/kern')
-rw-r--r-- | sys/kern/kern_clock.c | 4 | ||||
-rw-r--r-- | sys/kern/kern_clocksource.c | 6 | ||||
-rw-r--r-- | sys/kern/kern_tc.c | 9 | ||||
-rw-r--r-- | sys/kern/kern_timeout.c | 4 |
4 files changed, 16 insertions, 7 deletions
diff --git a/sys/kern/kern_clock.c b/sys/kern/kern_clock.c index 7fb70d0..192ec60 100644 --- a/sys/kern/kern_clock.c +++ b/sys/kern/kern_clock.c @@ -457,7 +457,7 @@ hardclock(int usermode, uintfptr_t pc) atomic_add_int((volatile int *)&ticks, 1); hardclock_cpu(usermode); - tc_ticktock(); + tc_ticktock(1); cpu_tick_calibration(); /* * If no separate statistics clock is available, run it from here. @@ -538,7 +538,7 @@ hardclock_anycpu(int cnt, int usermode) if (newticks > 0) { /* Dangerous and no need to call these things concurrently. */ if (atomic_cmpset_acq_int(&global_hardclock_run, 0, 1)) { - tc_ticktock(); + tc_ticktock(newticks); #ifdef DEVICE_POLLING /* This is very short and quick. */ hardclock_device_poll(); diff --git a/sys/kern/kern_clocksource.c b/sys/kern/kern_clocksource.c index 7654ace..e366ef9 100644 --- a/sys/kern/kern_clocksource.c +++ b/sys/kern/kern_clocksource.c @@ -49,6 +49,7 @@ __FBSDID("$FreeBSD$"); #include <sys/smp.h> #include <sys/sysctl.h> #include <sys/timeet.h> +#include <sys/timetc.h> #include <machine/atomic.h> #include <machine/clock.h> @@ -247,7 +248,10 @@ getnextcpuevent(struct bintime *event, int idle) state = DPCPU_PTR(timerstate); *event = state->nexthard; if (idle) { /* If CPU is idle - ask callouts for how long. */ - skip = callout_tickstofirst() - 1; + skip = 4; + if (curcpu == CPU_FIRST() && tc_min_ticktock_freq > skip) + skip = tc_min_ticktock_freq; + skip = callout_tickstofirst(hz / skip) - 1; CTR2(KTR_SPARE2, "skip at %d: %d", curcpu, skip); tmp = hardperiod; bintime_mul(&tmp, skip); diff --git a/sys/kern/kern_tc.c b/sys/kern/kern_tc.c index 811b24f..7a34a52 100644 --- a/sys/kern/kern_tc.c +++ b/sys/kern/kern_tc.c @@ -87,6 +87,8 @@ static struct timehands *volatile timehands = &th0; struct timecounter *timecounter = &dummy_timecounter; static struct timecounter *timecounters = &dummy_timecounter; +int tc_min_ticktock_freq = 1; + time_t time_second = 1; time_t time_uptime = 1; @@ -482,6 +484,8 @@ tc_windup(void) if (th->th_counter != timecounter) { th->th_counter = timecounter; th->th_offset_count = ncount; + tc_min_ticktock_freq = max(1, timecounter->tc_frequency / + (((uint64_t)timecounter->tc_counter_mask + 1) / 3)); } /*- @@ -767,11 +771,12 @@ static int tc_tick; SYSCTL_INT(_kern_timecounter, OID_AUTO, tick, CTLFLAG_RD, &tc_tick, 0, ""); void -tc_ticktock(void) +tc_ticktock(int cnt) { static int count; - if (++count < tc_tick) + count += cnt; + if (count < tc_tick) return; count = 0; tc_windup(); diff --git a/sys/kern/kern_timeout.c b/sys/kern/kern_timeout.c index 5697792..89fe544 100644 --- a/sys/kern/kern_timeout.c +++ b/sys/kern/kern_timeout.c @@ -280,7 +280,7 @@ callout_tick(void) } int -callout_tickstofirst(void) +callout_tickstofirst(int limit) { struct callout_cpu *cc; struct callout *c; @@ -291,7 +291,7 @@ callout_tickstofirst(void) cc = CC_SELF(); mtx_lock_spin_flags(&cc->cc_lock, MTX_QUIET); curticks = cc->cc_ticks; - while( skip < ncallout && skip < hz/8 ) { + while( skip < ncallout && skip < limit ) { sc = &cc->cc_callwheel[ (curticks+skip) & callwheelmask ]; /* search scanning ticks */ TAILQ_FOREACH( c, sc, c_links.tqe ){ |