diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-06 18:42:43 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-06 18:42:43 (GMT) |
commit | dda5f0a372873bca5f0b1d1866d7784dffd8b675 (patch) | |
tree | 1f745951b51ef9dcd127ca3c65ecb1d2ce4967c2 | |
parent | 65b2074f84be2287e020839e93b4cdaaf60eb37c (diff) | |
parent | 88606e80da0e8d862a42ee19e5bb60b01b940ea7 (diff) | |
download | linux-dda5f0a372873bca5f0b1d1866d7784dffd8b675.tar.xz |
Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
MAINTAINERS: Update timer related entries
timers: Use this_cpu_read
timerqueue: Make timerqueue_getnext() static inline
hrtimer: fix timerqueue conversion flub
hrtimers: Convert hrtimers to use timerlist infrastructure
timers: Fixup allmodconfig build issue
timers: Rename timerlist infrastructure to timerqueue
timers: Introduce timerlist infrastructure.
hrtimer: Remove stale comment on curr_timer
timer: Warn when del_timer_sync() is called in hardirq context
timer: Del_timer_sync() can be used in softirq context
timer: Make try_to_del_timer_sync() the same on SMP and UP
posix-timers: Annotate lock_timer()
timer: Permit statically-declared work with deferrable timers
time: Use ARRAY_SIZE macro in timecompare.c
timer: Initialize the field slack of timer_list
timer_list: Remove alignment padding on 64 bit when CONFIG_TIMER_STATS
time: Compensate for rounding on odd-frequency clocksources
Fix up trivial conflict in MAINTAINERS
-rw-r--r-- | MAINTAINERS | 16 | ||||
-rw-r--r-- | include/linux/hrtimer.h | 33 | ||||
-rw-r--r-- | include/linux/timer.h | 32 | ||||
-rw-r--r-- | include/linux/timerqueue.h | 50 | ||||
-rw-r--r-- | include/linux/workqueue.h | 8 | ||||
-rw-r--r-- | kernel/hrtimer.c | 83 | ||||
-rw-r--r-- | kernel/posix-timers.c | 10 | ||||
-rw-r--r-- | kernel/time/timecompare.c | 5 | ||||
-rw-r--r-- | kernel/time/timekeeping.c | 9 | ||||
-rw-r--r-- | kernel/time/timer_list.c | 8 | ||||
-rw-r--r-- | kernel/timer.c | 50 | ||||
-rw-r--r-- | lib/Makefile | 2 | ||||
-rw-r--r-- | lib/timerqueue.c | 107 |
13 files changed, 289 insertions, 124 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index b1dda78..c5c7292 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2812,6 +2812,10 @@ M: Thomas Gleixner <tglx@linutronix.de> S: Maintained F: Documentation/timers/ F: kernel/hrtimer.c +F: kernel/time/clockevents.c +F: kernel/time/tick*.* +F: kernel/time/timer_*.c +F include/linux/clockevents.h F: include/linux/hrtimer.h HIGH-SPEED SCC DRIVER FOR AX.25 @@ -5142,6 +5146,18 @@ L: alsa-devel@alsa-project.org (moderated for non-subscribers) S: Supported F: sound/soc/s3c24xx +TIMEKEEPING, NTP +M: John Stultz <johnstul@us.ibm.com> +M: Thomas Gleixner <tglx@linutronix.de> +S: Supported +F: include/linux/clocksource.h +F: include/linux/time.h +F: include/linux/timex.h +F: include/linux/timekeeping.h +F: kernel/time/clocksource.c +F: kernel/time/time*.c +F: kernel/time/ntp.c + TLG2300 VIDEO4LINUX-2 DRIVER M: Huang Shijie <shijie8@gmail.com> M: Kang Yong <kangyong@telegent.com> diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index fd0c1b8..330586f 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -22,7 +22,7 @@ #include <linux/wait.h> #include <linux/percpu.h> #include <linux/timer.h> - +#include <linux/timerqueue.h> struct hrtimer_clock_base; struct hrtimer_cpu_base; @@ -79,8 +79,8 @@ enum hrtimer_restart { /** * struct hrtimer - the basic hrtimer structure - * @node: red black tree node for time ordered insertion - * @_expires: the absolute expiry time in the hrtimers internal + * @node: timerqueue node, which also manages node.expires, + * the absolute expiry time in the hrtimers internal * representation. The time is related to the clock on * which the timer is based. Is setup by adding * slack to the _softexpires value. For non range timers @@ -101,8 +101,7 @@ enum hrtimer_restart { * The hrtimer structure must be initialized by hrtimer_init() */ struct hrtimer { - struct rb_node node; - ktime_t _expires; + struct timerqueue_node node; ktime_t _softexpires; enum hrtimer_restart (*function)(struct hrtimer *); struct hrtimer_clock_base *base; @@ -141,8 +140,7 @@ struct hrtimer_sleeper { struct hrtimer_clock_base { struct hrtimer_cpu_base *cpu_base; clockid_t index; - struct rb_root active; - struct rb_node *first; + struct timerqueue_head active; ktime_t resolution; ktime_t (*get_time)(void); ktime_t softirq_time; @@ -158,7 +156,6 @@ struct hrtimer_clock_base { * @lock: lock protecting the base and associated clock bases * and timers * @clock_base: array of clock bases for this cpu - * @curr_timer: the timer which is executing a callback right now * @expires_next: absolute time of the next event which was scheduled * via clock_set_next_event() * @hres_active: State of high resolution mode @@ -184,43 +181,43 @@ struct hrtimer_cpu_base { static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time) { - timer->_expires = time; + timer->node.expires = time; timer->_softexpires = time; } static inline void hrtimer_set_expires_range(struct hrtimer *timer, ktime_t time, ktime_t delta) { timer->_softexpires = time; - timer->_expires = ktime_add_safe(time, delta); + timer->node.expires = ktime_add_safe(time, delta); } static inline void hrtimer_set_expires_range_ns(struct hrtimer *timer, ktime_t time, unsigned long delta) { timer->_softexpires = time; - timer->_expires = ktime_add_safe(time, ns_to_ktime(delta)); + timer->node.expires = ktime_add_safe(time, ns_to_ktime(delta)); } static inline void hrtimer_set_expires_tv64(struct hrtimer *timer, s64 tv64) { - timer->_expires.tv64 = tv64; + timer->node.expires.tv64 = tv64; timer->_softexpires.tv64 = tv64; } static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time) { - timer->_expires = ktime_add_safe(timer->_expires, time); + timer->node.expires = ktime_add_safe(timer->node.expires, time); timer->_softexpires = ktime_add_safe(timer->_softexpires, time); } static inline void hrtimer_add_expires_ns(struct hrtimer *timer, u64 ns) { - timer->_expires = ktime_add_ns(timer->_expires, ns); + timer->node.expires = ktime_add_ns(timer->node.expires, ns); timer->_softexpires = ktime_add_ns(timer->_softexpires, ns); } static inline ktime_t hrtimer_get_expires(const struct hrtimer *timer) { - return timer->_expires; + return timer->node.expires; } static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer) @@ -230,7 +227,7 @@ static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer) static inline s64 hrtimer_get_expires_tv64(const struct hrtimer *timer) { - return timer->_expires.tv64; + return timer->node.expires.tv64; } static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer) { @@ -239,12 +236,12 @@ static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer) static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer) { - return ktime_to_ns(timer->_expires); + return ktime_to_ns(timer->node.expires); } static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer) { - return ktime_sub(timer->_expires, timer->base->get_time()); + return ktime_sub(timer->node.expires, timer->base->get_time()); } #ifdef CONFIG_HIGH_RES_TIMERS diff --git a/include/linux/timer.h b/include/linux/timer.h index 38cf093..6abd913 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -24,9 +24,9 @@ struct timer_list { int slack; #ifdef CONFIG_TIMER_STATS + int start_pid; void *start_site; char start_comm[16]; - int start_pid; #endif #ifdef CONFIG_LOCKDEP struct lockdep_map lockdep_map; @@ -48,12 +48,38 @@ extern struct tvec_base boot_tvec_bases; #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn) #endif +/* + * Note that all tvec_bases are 2 byte aligned and lower bit of + * base in timer_list is guaranteed to be zero. Use the LSB to + * indicate whether the timer is deferrable. + * + * A deferrable timer will work normally when the system is busy, but + * will not cause a CPU to come out of idle just to service it; instead, + * the timer will be serviced when the CPU eventually wakes up with a + * subsequent non-deferrable timer. + */ +#define TBASE_DEFERRABLE_FLAG (0x1) + #define TIMER_INITIALIZER(_function, _expires, _data) { \ .entry = { .prev = TIMER_ENTRY_STATIC }, \ .function = (_function), \ .expires = (_expires), \ .data = (_data), \ .base = &boot_tvec_bases, \ + .slack = -1, \ + __TIMER_LOCKDEP_MAP_INITIALIZER( \ + __FILE__ ":" __stringify(__LINE__)) \ + } + +#define TBASE_MAKE_DEFERRED(ptr) ((struct tvec_base *) \ + ((unsigned char *)(ptr) + TBASE_DEFERRABLE_FLAG)) + +#define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data) {\ + .entry = { .prev = TIMER_ENTRY_STATIC }, \ + .function = (_function), \ + .expires = (_expires), \ + .data = (_data), \ + .base = TBASE_MAKE_DEFERRED(&boot_tvec_bases), \ __TIMER_LOCKDEP_MAP_INITIALIZER( \ __FILE__ ":" __stringify(__LINE__)) \ } @@ -248,11 +274,11 @@ static inline void timer_stats_timer_clear_start_info(struct timer_list *timer) extern void add_timer(struct timer_list *timer); +extern int try_to_del_timer_sync(struct timer_list *timer); + #ifdef CONFIG_SMP - extern int try_to_del_timer_sync(struct timer_list *timer); extern int del_timer_sync(struct timer_list *timer); #else -# define try_to_del_timer_sync(t) del_timer(t) # define del_timer_sync(t) del_timer(t) #endif diff --git a/include/linux/timerqueue.h b/include/linux/timerqueue.h new file mode 100644 index 0000000..d24aaba --- /dev/null +++ b/include/linux/timerqueue.h @@ -0,0 +1,50 @@ +#ifndef _LINUX_TIMERQUEUE_H +#define _LINUX_TIMERQUEUE_H + +#include <linux/rbtree.h> +#include <linux/ktime.h> + + +struct timerqueue_node { + struct rb_node node; + ktime_t expires; +}; + +struct timerqueue_head { + struct rb_root head; + struct timerqueue_node *next; +}; + + +extern void timerqueue_add(struct timerqueue_head *head, + struct timerqueue_node *node); +extern void timerqueue_del(struct timerqueue_head *head, + struct timerqueue_node *node); +extern struct timerqueue_node *timerqueue_iterate_next( + struct timerqueue_node *node); + +/** + * timerqueue_getnext - Returns the timer with the earlies expiration time + * + * @head: head of timerqueue + * + * Returns a pointer to the timer node that has the + * earliest expiration time. + */ +static inline +struct timerqueue_node *timerqueue_getnext(struct timerqueue_head *head) +{ + return head->next; +} + +static inline void timerqueue_init(struct timerqueue_node *node) +{ + RB_CLEAR_NODE(&node->node); +} + +static inline void timerqueue_init_head(struct timerqueue_head *head) +{ + head->head = RB_ROOT; + head->next = NULL; +} +#endif /* _LINUX_TIMERQUEUE_H */ diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 0c0771f..bd257fe 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -127,12 +127,20 @@ struct execute_work { .timer = TIMER_INITIALIZER(NULL, 0, 0), \ } +#define __DEFERRED_WORK_INITIALIZER(n, f) { \ + .work = __WORK_INITIALIZER((n).work, (f)), \ + .timer = TIMER_DEFERRED_INITIALIZER(NULL, 0, 0), \ + } + #define DECLARE_WORK(n, f) \ struct work_struct n = __WORK_INITIALIZER(n, f) #define DECLARE_DELAYED_WORK(n, f) \ struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f) +#define DECLARE_DEFERRED_WORK(n, f) \ + struct delayed_work n = __DEFERRED_WORK_INITIALIZER(n, f) + /* * initialize a work item's function pointer */ diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 72206cf..f2429fc 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -516,10 +516,13 @@ hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal) for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) { struct hrtimer *timer; + struct timerqueue_node *next; - if (!base->first) + next = timerqueue_getnext(&base->active); + if (!next) continue; - timer = rb_entry(base->first, struct hrtimer, node); + timer = container_of(next, struct hrtimer, node); + expires = ktime_sub(hrtimer_get_expires(timer), base->offset); /* * clock_was_set() has changed base->offset so the @@ -840,48 +843,17 @@ EXPORT_SYMBOL_GPL(hrtimer_forward); static int enqueue_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base) { - struct rb_node **link = &base->active.rb_node; - struct rb_node *parent = NULL; - struct hrtimer *entry; - int leftmost = 1; - debug_activate(timer); - /* - * Find the right place in the rbtree: - */ - while (*link) { - parent = *link; - entry = rb_entry(parent, struct hrtimer, node); - /* - * We dont care about collisions. Nodes with - * the same expiry time stay together. - */ - if (hrtimer_get_expires_tv64(timer) < - hrtimer_get_expires_tv64(entry)) { - link = &(*link)->rb_left; - } else { - link = &(*link)->rb_right; - leftmost = 0; - } - } - - /* - * Insert the timer to the rbtree and check whether it - * replaces the first pending timer - */ - if (leftmost) - base->first = &timer->node; + timerqueue_add(&base->active, &timer->node); - rb_link_node(&timer->node, parent, link); - rb_insert_color(&timer->node, &base->active); /* * HRTIMER_STATE_ENQUEUED is or'ed to the current state to preserve the * state of a possibly running callback. */ timer->state |= HRTIMER_STATE_ENQUEUED; - return leftmost; + return (&timer->node == base->active.next); } /* @@ -901,12 +873,7 @@ static void __remove_hrtimer(struct hrtimer *timer, if (!(timer->state & HRTIMER_STATE_ENQUEUED)) goto out; - /* - * Remove the timer from the rbtree and replace the first - * entry pointer if necessary. - */ - if (base->first == &timer->node) { - base->first = rb_next(&timer->node); + if (&timer->node == timerqueue_getnext(&base->active)) { #ifdef CONFIG_HIGH_RES_TIMERS /* Reprogram the clock event device. if enabled */ if (reprogram && hrtimer_hres_active()) { @@ -919,7 +886,7 @@ static void __remove_hrtimer(struct hrtimer *timer, } #endif } - rb_erase(&timer->node, &base->active); + timerqueue_del(&base->active, &timer->node); out: timer->state = newstate; } @@ -1128,11 +1095,13 @@ ktime_t hrtimer_get_next_event(void) if (!hrtimer_hres_active()) { for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) { struct hrtimer *timer; + struct timerqueue_node *next; - if (!base->first) + next = timerqueue_getnext(&base->active); + if (!next) continue; - timer = rb_entry(base->first, struct hrtimer, node); + timer = container_of(next, struct hrtimer, node); delta.tv64 = hrtimer_get_expires_tv64(timer); delta = ktime_sub(delta, base->get_time()); if (delta.tv64 < mindelta.tv64) @@ -1162,6 +1131,7 @@ static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, timer->base = &cpu_base->clock_base[clock_id]; hrtimer_init_timer_hres(timer); + timerqueue_init(&timer->node); #ifdef CONFIG_TIMER_STATS timer->start_site = NULL; @@ -1278,14 +1248,14 @@ retry: for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { ktime_t basenow; - struct rb_node *node; + struct timerqueue_node *node; basenow = ktime_add(now, base->offset); - while ((node = base->first)) { + while ((node = timerqueue_getnext(&base->active))) { struct hrtimer *timer; - timer = rb_entry(node, struct hrtimer, node); + timer = container_of(node, struct hrtimer, node); /* * The immediate goal for using the softexpires is @@ -1441,7 +1411,7 @@ void hrtimer_run_pending(void) */ void hrtimer_run_queues(void) { - struct rb_node *node; + struct timerqueue_node *node; struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); struct hrtimer_clock_base *base; int index, gettime = 1; @@ -1451,8 +1421,7 @@ void hrtimer_run_queues(void) for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) { base = &cpu_base->clock_base[index]; - - if (!base->first) + if (!timerqueue_getnext(&base->active)) continue; if (gettime) { @@ -1462,10 +1431,10 @@ void hrtimer_run_queues(void) raw_spin_lock(&cpu_base->lock); - while ((node = base->first)) { + while ((node = timerqueue_getnext(&base->active))) { struct hrtimer *timer; - timer = rb_entry(node, struct hrtimer, node); + timer = container_of(node, struct hrtimer, node); if (base->softirq_time.tv64 <= hrtimer_get_expires_tv64(timer)) break; @@ -1630,8 +1599,10 @@ static void __cpuinit init_hrtimers_cpu(int cpu) raw_spin_lock_init(&cpu_base->lock); - for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) + for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { cpu_base->clock_base[i].cpu_base = cpu_base; + timerqueue_init_head(&cpu_base->clock_base[i].active); + } hrtimer_init_hres(cpu_base); } @@ -1642,10 +1613,10 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, struct hrtimer_clock_base *new_base) { struct hrtimer *timer; - struct rb_node *node; + struct timerqueue_node *node; - while ((node = rb_first(&old_base->active))) { - timer = rb_entry(node, struct hrtimer, node); + while ((node = timerqueue_getnext(&old_base->active))) { + timer = container_of(node, struct hrtimer, node); BUG_ON(hrtimer_callback_running(timer)); debug_deactivate(timer); diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index 9ca4973..93bd2eb 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -145,7 +145,13 @@ static int common_timer_del(struct k_itimer *timer); static enum hrtimer_restart posix_timer_fn(struct hrtimer *data); -static struct k_itimer *lock_timer(timer_t timer_id, unsigned long *flags); +static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags); + +#define lock_timer(tid, flags) \ +({ struct k_itimer *__timr; \ + __cond_lock(&__timr->it_lock, __timr = __lock_timer(tid, flags)); \ + __timr; \ +}) static inline void unlock_timer(struct k_itimer *timr, unsigned long flags) { @@ -619,7 +625,7 @@ out: * the find to the timer lock. To avoid a dead lock, the timer id MUST * be release with out holding the timer lock. */ -static struct k_itimer *lock_timer(timer_t timer_id, unsigned long *flags) +static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags) { struct k_itimer *timr; /* diff --git a/kernel/time/timecompare.c b/kernel/time/timecompare.c index ac38fbb..a9ae369 100644 --- a/kernel/time/timecompare.c +++ b/kernel/time/timecompare.c @@ -21,6 +21,7 @@ #include <linux/module.h> #include <linux/slab.h> #include <linux/math64.h> +#include <linux/kernel.h> /* * fixed point arithmetic scale factor for skew @@ -57,11 +58,11 @@ int timecompare_offset(struct timecompare *sync, int index; int num_samples = sync->num_samples; - if (num_samples > sizeof(buffer)/sizeof(buffer[0])) { + if (num_samples > ARRAY_SIZE(buffer)) { samples = kmalloc(sizeof(*samples) * num_samples, GFP_ATOMIC); if (!samples) { samples = buffer; - num_samples = sizeof(buffer)/sizeof(buffer[0]); + num_samples = ARRAY_SIZE(buffer); } } else { samples = buffer; diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 49010d8..5bb86da 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -32,6 +32,8 @@ struct timekeeper { cycle_t cycle_interval; /* Number of clock shifted nano seconds in one NTP interval. */ u64 xtime_interval; + /* shifted nano seconds left over when rounding cycle_interval */ + s64 xtime_remainder; /* Raw nano seconds accumulated per NTP interval. */ u32 raw_interval; @@ -62,7 +64,7 @@ struct timekeeper timekeeper; static void timekeeper_setup_internals(struct clocksource *clock) { cycle_t interval; - u64 tmp; + u64 tmp, ntpinterval; timekeeper.clock = clock; clock->cycle_last = clock->read(clock); @@ -70,6 +72,7 @@ static void timekeeper_setup_internals(struct clocksource *clock) /* Do the ns -> cycle conversion first, using original mult */ tmp = NTP_INTERVAL_LENGTH; tmp <<= clock->shift; + ntpinterval = tmp; tmp += clock->mult/2; do_div(tmp, clock->mult); if (tmp == 0) @@ -80,6 +83,7 @@ static void timekeeper_setup_internals(struct clocksource *clock) /* Go back from cycles -> shifted ns */ timekeeper.xtime_interval = (u64) interval * clock->mult; + timekeeper.xtime_remainder = ntpinterval - timekeeper.xtime_interval; timekeeper.raw_interval = ((u64) interval * clock->mult) >> clock->shift; @@ -719,7 +723,8 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift) /* Accumulate error between NTP and clock interval */ timekeeper.ntp_error += tick_length << shift; - timekeeper.ntp_error -= timekeeper.xtime_interval << + timekeeper.ntp_error -= + (timekeeper.xtime_interval + timekeeper.xtime_remainder) << (timekeeper.ntp_error_shift + shift); return offset; diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index ab8f5e3..32a19f9 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -79,26 +79,26 @@ print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base, { struct hrtimer *timer, tmp; unsigned long next = 0, i; - struct rb_node *curr; + struct timerqueue_node *curr; unsigned long flags; next_one: i = 0; raw_spin_lock_irqsave(&base->cpu_base->lock, flags); - curr = base->first; + curr = timerqueue_getnext(&base->active); /* * Crude but we have to do this O(N*N) thing, because * we have to unlock the base when printing: */ while (curr && i < next) { - curr = rb_next(curr); + curr = timerqueue_iterate_next(curr); i++; } if (curr) { - timer = rb_entry(curr, struct hrtimer, node); + timer = container_of(curr, struct hrtimer, node); tmp = *timer; raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags); diff --git a/kernel/timer.c b/kernel/timer.c index 353b922..43ca993 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -88,18 +88,6 @@ struct tvec_base boot_tvec_bases; EXPORT_SYMBOL(boot_tvec_bases); static DEFINE_PER_CPU(struct tvec_base *, tvec_bases) = &boot_tvec_bases; -/* - * Note that all tvec_bases are 2 byte aligned and lower bit of - * base in timer_list is guaranteed to be zero. Use the LSB to - * indicate whether the timer is deferrable. - * - * A deferrable timer will work normally when the system is busy, but - * will not cause a CPU to come out of idle just to service it; instead, - * the timer will be serviced when the CPU eventually wakes up with a - * subsequent non-deferrable timer. - */ -#define TBASE_DEFERRABLE_FLAG (0x1) - /* Functions below help us manage 'deferrable' flag */ static inline unsigned int tbase_get_deferrable(struct tvec_base *base) { @@ -113,8 +101,7 @@ static inline struct tvec_base *tbase_get_base(struct tvec_base *base) static inline void timer_set_deferrable(struct timer_list *timer) { - timer->base = ((struct tvec_base *)((unsigned long)(timer->base) | - TBASE_DEFERRABLE_FLAG)); + timer->base = TBASE_MAKE_DEFERRED(timer->base); } static inline void @@ -343,15 +330,6 @@ void set_timer_slack(struct timer_list *timer, int slack_hz) } EXPORT_SYMBOL_GPL(set_timer_slack); - -static inline void set_running_timer(struct tvec_base *base, - struct timer_list *timer) -{ -#ifdef CONFIG_SMP - base->running_timer = timer; -#endif -} - static void internal_add_timer(struct tvec_base *base, struct timer_list *timer) { unsigned long expires = timer->expires; @@ -936,15 +914,12 @@ int del_timer(struct timer_list *timer) } EXPORT_SYMBOL(del_timer); -#ifdef CONFIG_SMP /** * try_to_del_timer_sync - Try to deactivate a timer * @timer: timer do del * * This function tries to deactivate a timer. Upon successful (ret >= 0) * exit the timer is not queued and the handler is not running on any CPU. - * - * It must not be called from interrupt contexts. */ int try_to_del_timer_sync(struct timer_list *timer) { @@ -973,6 +948,7 @@ out: } EXPORT_SYMBOL(try_to_del_timer_sync); +#ifdef CONFIG_SMP /** * del_timer_sync - deactivate a timer and wait for the handler to finish. * @timer: the timer to be deactivated @@ -983,7 +959,7 @@ EXPORT_SYMBOL(try_to_del_timer_sync); * * Synchronization rules: Callers must prevent restarting of the timer, * otherwise this function is meaningless. It must not be called from - * interrupt contexts. The caller must not hold locks which would prevent + * hardirq contexts. The caller must not hold locks which would prevent * completion of the timer's handler. The timer's handler must not call * add_timer_on(). Upon exit the timer is not queued and the handler is * not running on any CPU. @@ -993,14 +969,16 @@ EXPORT_SYMBOL(try_to_del_timer_sync); int del_timer_sync(struct timer_list *timer) { #ifdef CONFIG_LOCKDEP - unsigned long flags; - - local_irq_save(flags); + local_bh_disable(); lock_map_acquire(&timer->lockdep_map); lock_map_release(&timer->lockdep_map); - local_irq_restore(flags); + local_bh_enable(); #endif - + /* + * don't use it in hardirq context, because it + * could lead to deadlock. + */ + WARN_ON(in_irq()); for (;;) { int ret = try_to_del_timer_sync(timer); if (ret >= 0) @@ -1111,7 +1089,7 @@ static inline void __run_timers(struct tvec_base *base) timer_stats_account_timer(timer); - set_running_timer(base, timer); + base->running_timer = timer; detach_timer(timer, 1); spin_unlock_irq(&base->lock); @@ -1119,7 +1097,7 @@ static inline void __run_timers(struct tvec_base *base) spin_lock_irq(&base->lock); } } - set_running_timer(base, NULL); + base->running_timer = NULL; spin_unlock_irq(&base->lock); } @@ -1249,7 +1227,7 @@ static unsigned long cmp_next_hrtimer_event(unsigned long now, */ unsigned long get_next_timer_interrupt(unsigned long now) { - struct tvec_base *base = __get_cpu_var(tvec_bases); + struct tvec_base *base = __this_cpu_read(tvec_bases); unsigned long expires; /* @@ -1298,7 +1276,7 @@ void update_process_times(int user_tick) */ static void run_timer_softirq(struct softirq_action *h) { - struct tvec_base *base = __get_cpu_var(tvec_bases); + struct tvec_base *base = __this_cpu_read(tvec_bases); hrtimer_run_pending(); diff --git a/lib/Makefile b/lib/Makefile index e6a3763..9e2db72 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -8,7 +8,7 @@ KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS)) endif lib-y := ctype.o string.o vsprintf.o cmdline.o \ - rbtree.o radix-tree.o dump_stack.o \ + rbtree.o radix-tree.o dump_stack.o timerqueue.o\ idr.o int_sqrt.o extable.o prio_tree.o \ sha1.o irq_regs.o reciprocal_div.o argv_split.o \ proportions.o prio_heap.o ratelimit.o show_mem.o \ diff --git a/lib/timerqueue.c b/lib/timerqueue.c new file mode 100644 index 0000000..e3a1050 --- /dev/null +++ b/lib/timerqueue.c @@ -0,0 +1,107 @@ +/* + * Generic Timer-queue + * + * Manages a simple queue of timers, ordered by expiration time. + * Uses rbtrees for quick list adds and expiration. + * + * NOTE: All of the following functions need to be serialized + * to avoid races. No locking is done by this libary code. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/timerqueue.h> +#include <linux/rbtree.h> +#include <linux/module.h> + +/** + * timerqueue_add - Adds timer to timerqueue. + * + * @head: head of timerqueue + * @node: timer node to be added + * + * Adds the timer node to the timerqueue, sorted by the + * node's expires value. + */ +void timerqueue_add(struct timerqueue_head *head, struct timerqueue_node *node) +{ + struct rb_node **p = &head->head.rb_node; + struct rb_node *parent = NULL; + struct timerqueue_node *ptr; + + /* Make sure we don't add nodes that are already added */ + WARN_ON_ONCE(!RB_EMPTY_NODE(&node->node)); + + while (*p) { + parent = *p; + ptr = rb_entry(parent, struct timerqueue_node, node); + if (node->expires.tv64 < ptr->expires.tv64) + p = &(*p)->rb_left; + else + p = &(*p)->rb_right; + } + rb_link_node(&node->node, parent, p); + rb_insert_color(&node->node, &head->head); + + if (!head->next || node->expires.tv64 < head->next->expires.tv64) + head->next = node; +} +EXPORT_SYMBOL_GPL(timerqueue_add); + +/** + * timerqueue_del - Removes a timer from the timerqueue. + * + * @head: head of timerqueue + * @node: timer node to be removed + * + * Removes the timer node from the timerqueue. + */ +void timerqueue_del(struct timerqueue_head *head, struct timerqueue_node *node) +{ + WARN_ON_ONCE(RB_EMPTY_NODE(&node->node)); + + /* update next pointer */ + if (head->next == node) { + struct rb_node *rbn = rb_next(&node->node); + + head->next = rbn ? + rb_entry(rbn, struct timerqueue_node, node) : NULL; + } + rb_erase(&node->node, &head->head); + RB_CLEAR_NODE(&node->node); +} +EXPORT_SYMBOL_GPL(timerqueue_del); + +/** + * timerqueue_iterate_next - Returns the timer after the provided timer + * + * @node: Pointer to a timer. + * + * Provides the timer that is after the given node. This is used, when + * necessary, to iterate through the list of timers in a timer list + * without modifying the list. + */ +struct timerqueue_node *timerqueue_iterate_next(struct timerqueue_node *node) +{ + struct rb_node *next; + + if (!node) + return NULL; + next = rb_next(&node->node); + if (!next) + return NULL; + return container_of(next, struct timerqueue_node, node); +} +EXPORT_SYMBOL_GPL(timerqueue_iterate_next); |