X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Fhrtimer.c;h=2b6e1757aeddf118f43c31111f46224b00f5d25e;hb=33052057e3e2db7f37fc78aa3f25c98f7e989fae;hp=e6e8278bcb18173f137b08d8602b7eb183b9d558;hpb=288867ec5c377db82933b64460ce050e5c998ee9;p=linux-2.6 diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index e6e8278bcb..2b6e1757ae 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -21,6 +21,12 @@ * Credits: * based on kernel/timer.c * + * Help, testing, suggestions, bugfixes, improvements were + * provided by: + * + * George Anzinger, Andrew Morton, Steven Rostedt, Roman Zippel + * et. al. + * * For licencing details see kernel-base/COPYING */ @@ -66,6 +72,12 @@ EXPORT_SYMBOL_GPL(ktime_get_real); /* * The timer bases: + * + * Note: If we want to add new timer bases, we have to skip the two + * clock ids captured by the cpu-timers. We do this by holding empty + * entries rather than doing math adjustment of the clock ids. + * This ensures that we capture erroneous accesses to these clock ids + * rather than moving them into the range of valid clock id's. */ #define MAX_HRTIMER_BASES 2 @@ -272,10 +284,10 @@ void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) * @interval: the interval to forward * * Forward the timer expiry so it will expire in the future. - * The number of overruns is added to the overrun field. + * Returns the number of overruns. */ unsigned long -hrtimer_forward(struct hrtimer *timer, const ktime_t interval) +hrtimer_forward(struct hrtimer *timer, ktime_t interval) { unsigned long orun = 1; ktime_t delta, now; @@ -287,6 +299,9 @@ hrtimer_forward(struct hrtimer *timer, const ktime_t interval) if (delta.tv64 < 0) return 0; + if (interval.tv64 < timer->base->resolution.tv64) + interval.tv64 = timer->base->resolution.tv64; + if (unlikely(delta.tv64 >= interval.tv64)) { nsec_t incr = ktime_to_ns(interval); @@ -480,29 +495,25 @@ ktime_t hrtimer_get_remaining(const struct hrtimer *timer) } /** - * hrtimer_rebase - rebase an initialized hrtimer to a different base + * hrtimer_init - initialize a timer to the given clock * - * @timer: the timer to be rebased + * @timer: the timer to be initialized * @clock_id: the clock to be used + * @mode: timer mode abs/rel */ -void hrtimer_rebase(struct hrtimer *timer, const clockid_t clock_id) +void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, + enum hrtimer_mode mode) { struct hrtimer_base *bases; + memset(timer, 0, sizeof(struct hrtimer)); + bases = per_cpu(hrtimer_bases, raw_smp_processor_id()); - timer->base = &bases[clock_id]; -} -/** - * hrtimer_init - initialize a timer to the given clock - * - * @timer: the timer to be initialized - * @clock_id: the clock to be used - */ -void hrtimer_init(struct hrtimer *timer, const clockid_t clock_id) -{ - memset(timer, 0, sizeof(struct hrtimer)); - hrtimer_rebase(timer, clock_id); + if (clock_id == CLOCK_REALTIME && mode != HRTIMER_ABS) + clock_id = CLOCK_MONOTONIC; + + timer->base = &bases[clock_id]; } /** @@ -518,9 +529,8 @@ int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp) { struct hrtimer_base *bases; - tp->tv_sec = 0; bases = per_cpu(hrtimer_bases, raw_smp_processor_id()); - tp->tv_nsec = bases[which_clock].resolution; + *tp = ktime_to_timespec(bases[which_clock].resolution); return 0; } @@ -548,6 +558,7 @@ static inline void run_hrtimer_queue(struct hrtimer_base *base) fn = timer->function; data = timer->data; set_curr_timer(base, timer); + timer->state = HRTIMER_RUNNING; __remove_hrtimer(timer, base); spin_unlock_irq(&base->lock); @@ -563,6 +574,10 @@ static inline void run_hrtimer_queue(struct hrtimer_base *base) spin_lock_irq(&base->lock); + /* Another CPU has added back the timer */ + if (timer->state != HRTIMER_RUNNING) + continue; + if (restart == HRTIMER_RESTART) enqueue_hrtimer(timer, base); else @@ -636,17 +651,17 @@ schedule_hrtimer_interruptible(struct hrtimer *timer, return schedule_hrtimer(timer, mode); } -static long __sched -nanosleep_restart(struct restart_block *restart, clockid_t clockid) +static long __sched nanosleep_restart(struct restart_block *restart) { - struct timespec __user *rmtp, tu; + struct timespec __user *rmtp; + struct timespec tu; void *rfn_save = restart->fn; struct hrtimer timer; ktime_t rem; restart->fn = do_no_restart_syscall; - hrtimer_init(&timer, clockid); + hrtimer_init(&timer, (clockid_t) restart->arg3, HRTIMER_ABS); timer.expires.tv64 = ((u64)restart->arg1 << 32) | (u64) restart->arg0; @@ -666,16 +681,6 @@ nanosleep_restart(struct restart_block *restart, clockid_t clockid) return -ERESTART_RESTARTBLOCK; } -static long __sched nanosleep_restart_mono(struct restart_block *restart) -{ - return nanosleep_restart(restart, CLOCK_MONOTONIC); -} - -static long __sched nanosleep_restart_real(struct restart_block *restart) -{ - return nanosleep_restart(restart, CLOCK_REALTIME); -} - long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, const enum hrtimer_mode mode, const clockid_t clockid) { @@ -684,7 +689,7 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, struct timespec tu; ktime_t rem; - hrtimer_init(&timer, clockid); + hrtimer_init(&timer, clockid, mode); timer.expires = timespec_to_ktime(*rqtp); @@ -692,7 +697,7 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, if (rem.tv64 <= 0) return 0; - /* Absolute timers do not update the rmtp value: */ + /* Absolute timers do not update the rmtp value and restart: */ if (mode == HRTIMER_ABS) return -ERESTARTNOHAND; @@ -702,11 +707,11 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, return -EFAULT; restart = ¤t_thread_info()->restart_block; - restart->fn = (clockid == CLOCK_MONOTONIC) ? - nanosleep_restart_mono : nanosleep_restart_real; + restart->fn = nanosleep_restart; restart->arg0 = timer.expires.tv64 & 0xFFFFFFFF; restart->arg1 = timer.expires.tv64 >> 32; restart->arg2 = (unsigned long) rmtp; + restart->arg3 = (unsigned long) timer.base->index; return -ERESTART_RESTARTBLOCK; } @@ -733,10 +738,8 @@ static void __devinit init_hrtimers_cpu(int cpu) struct hrtimer_base *base = per_cpu(hrtimer_bases, cpu); int i; - for (i = 0; i < MAX_HRTIMER_BASES; i++) { + for (i = 0; i < MAX_HRTIMER_BASES; i++, base++) spin_lock_init(&base->lock); - base++; - } } #ifdef CONFIG_HOTPLUG_CPU