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authorThomas Gleixner <tglx@linutronix.de>2008-10-22 09:48:06 +0200
committerThomas Gleixner <tglx@linutronix.de>2008-10-22 09:48:06 +0200
commit268a3dcfea2077fca60d3715caa5c96f9b5e6ea7 (patch)
treec2232774508424e677e27f296090a68c775e4669 /kernel/hrtimer.c
parentNOHZ: fix thinko in the timer restart code path (diff)
parenthrtimers: add missing docbook comments to struct hrtimer (diff)
downloadlinux-268a3dcfea2077fca60d3715caa5c96f9b5e6ea7.tar.xz
linux-268a3dcfea2077fca60d3715caa5c96f9b5e6ea7.zip
Merge branch 'timers/range-hrtimers' into v28-range-hrtimers-for-linus-v2
Conflicts: kernel/time/tick-sched.c Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/hrtimer.c')
-rw-r--r--kernel/hrtimer.c206
1 files changed, 185 insertions, 21 deletions
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 95978f48e039..2b465dfde426 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -517,7 +517,7 @@ static void hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base)
if (!base->first)
continue;
timer = rb_entry(base->first, struct hrtimer, node);
- expires = ktime_sub(timer->expires, base->offset);
+ expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
if (expires.tv64 < cpu_base->expires_next.tv64)
cpu_base->expires_next = expires;
}
@@ -539,10 +539,10 @@ static int hrtimer_reprogram(struct hrtimer *timer,
struct hrtimer_clock_base *base)
{
ktime_t *expires_next = &__get_cpu_var(hrtimer_bases).expires_next;
- ktime_t expires = ktime_sub(timer->expires, base->offset);
+ ktime_t expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
int res;
- WARN_ON_ONCE(timer->expires.tv64 < 0);
+ WARN_ON_ONCE(hrtimer_get_expires_tv64(timer) < 0);
/*
* When the callback is running, we do not reprogram the clock event
@@ -795,7 +795,7 @@ u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
u64 orun = 1;
ktime_t delta;
- delta = ktime_sub(now, timer->expires);
+ delta = ktime_sub(now, hrtimer_get_expires(timer));
if (delta.tv64 < 0)
return 0;
@@ -807,8 +807,8 @@ u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
s64 incr = ktime_to_ns(interval);
orun = ktime_divns(delta, incr);
- timer->expires = ktime_add_ns(timer->expires, incr * orun);
- if (timer->expires.tv64 > now.tv64)
+ hrtimer_add_expires_ns(timer, incr * orun);
+ if (hrtimer_get_expires_tv64(timer) > now.tv64)
return orun;
/*
* This (and the ktime_add() below) is the
@@ -816,7 +816,7 @@ u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
*/
orun++;
}
- timer->expires = ktime_add_safe(timer->expires, interval);
+ hrtimer_add_expires(timer, interval);
return orun;
}
@@ -848,7 +848,8 @@ static void enqueue_hrtimer(struct hrtimer *timer,
* We dont care about collisions. Nodes with
* the same expiry time stay together.
*/
- if (timer->expires.tv64 < entry->expires.tv64) {
+ if (hrtimer_get_expires_tv64(timer) <
+ hrtimer_get_expires_tv64(entry)) {
link = &(*link)->rb_left;
} else {
link = &(*link)->rb_right;
@@ -945,9 +946,10 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
}
/**
- * hrtimer_start - (re)start an relative timer on the current CPU
+ * hrtimer_start_range_ns - (re)start an hrtimer on the current CPU
* @timer: the timer to be added
* @tim: expiry time
+ * @delta_ns: "slack" range for the timer
* @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL)
*
* Returns:
@@ -955,7 +957,8 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
* 1 when the timer was active
*/
int
-hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
+hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, unsigned long delta_ns,
+ const enum hrtimer_mode mode)
{
struct hrtimer_clock_base *base, *new_base;
unsigned long flags;
@@ -983,7 +986,7 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
#endif
}
- timer->expires = tim;
+ hrtimer_set_expires_range_ns(timer, tim, delta_ns);
timer_stats_hrtimer_set_start_info(timer);
@@ -1016,8 +1019,26 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
return ret;
}
+EXPORT_SYMBOL_GPL(hrtimer_start_range_ns);
+
+/**
+ * hrtimer_start - (re)start an hrtimer on the current CPU
+ * @timer: the timer to be added
+ * @tim: expiry time
+ * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL)
+ *
+ * Returns:
+ * 0 on success
+ * 1 when the timer was active
+ */
+int
+hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
+{
+ return hrtimer_start_range_ns(timer, tim, 0, mode);
+}
EXPORT_SYMBOL_GPL(hrtimer_start);
+
/**
* hrtimer_try_to_cancel - try to deactivate a timer
* @timer: hrtimer to stop
@@ -1077,7 +1098,7 @@ ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
ktime_t rem;
base = lock_hrtimer_base(timer, &flags);
- rem = ktime_sub(timer->expires, base->get_time());
+ rem = hrtimer_expires_remaining(timer);
unlock_hrtimer_base(timer, &flags);
return rem;
@@ -1109,7 +1130,7 @@ ktime_t hrtimer_get_next_event(void)
continue;
timer = rb_entry(base->first, struct hrtimer, node);
- delta.tv64 = timer->expires.tv64;
+ delta.tv64 = hrtimer_get_expires_tv64(timer);
delta = ktime_sub(delta, base->get_time());
if (delta.tv64 < mindelta.tv64)
mindelta.tv64 = delta.tv64;
@@ -1310,10 +1331,23 @@ void hrtimer_interrupt(struct clock_event_device *dev)
timer = rb_entry(node, struct hrtimer, node);
- if (basenow.tv64 < timer->expires.tv64) {
+ /*
+ * The immediate goal for using the softexpires is
+ * minimizing wakeups, not running timers at the
+ * earliest interrupt after their soft expiration.
+ * This allows us to avoid using a Priority Search
+ * Tree, which can answer a stabbing querry for
+ * overlapping intervals and instead use the simple
+ * BST we already have.
+ * We don't add extra wakeups by delaying timers that
+ * are right-of a not yet expired timer, because that
+ * timer will have to trigger a wakeup anyway.
+ */
+
+ if (basenow.tv64 < hrtimer_get_softexpires_tv64(timer)) {
ktime_t expires;
- expires = ktime_sub(timer->expires,
+ expires = ktime_sub(hrtimer_get_expires(timer),
base->offset);
if (expires.tv64 < expires_next.tv64)
expires_next = expires;
@@ -1349,6 +1383,30 @@ void hrtimer_interrupt(struct clock_event_device *dev)
raise_softirq(HRTIMER_SOFTIRQ);
}
+/**
+ * hrtimer_peek_ahead_timers -- run soft-expired timers now
+ *
+ * hrtimer_peek_ahead_timers will peek at the timer queue of
+ * the current cpu and check if there are any timers for which
+ * the soft expires time has passed. If any such timers exist,
+ * they are run immediately and then removed from the timer queue.
+ *
+ */
+void hrtimer_peek_ahead_timers(void)
+{
+ struct tick_device *td;
+ unsigned long flags;
+
+ if (!hrtimer_hres_active())
+ return;
+
+ local_irq_save(flags);
+ td = &__get_cpu_var(tick_cpu_device);
+ if (td && td->evtdev)
+ hrtimer_interrupt(td->evtdev);
+ local_irq_restore(flags);
+}
+
static void run_hrtimer_softirq(struct softirq_action *h)
{
run_hrtimer_pending(&__get_cpu_var(hrtimer_bases));
@@ -1414,7 +1472,8 @@ void hrtimer_run_queues(void)
struct hrtimer *timer;
timer = rb_entry(node, struct hrtimer, node);
- if (base->softirq_time.tv64 <= timer->expires.tv64)
+ if (base->softirq_time.tv64 <=
+ hrtimer_get_expires_tv64(timer))
break;
if (timer->cb_mode == HRTIMER_CB_SOFTIRQ) {
@@ -1462,7 +1521,7 @@ static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mod
do {
set_current_state(TASK_INTERRUPTIBLE);
- hrtimer_start(&t->timer, t->timer.expires, mode);
+ hrtimer_start_expires(&t->timer, mode);
if (!hrtimer_active(&t->timer))
t->task = NULL;
@@ -1484,7 +1543,7 @@ static int update_rmtp(struct hrtimer *timer, struct timespec __user *rmtp)
struct timespec rmt;
ktime_t rem;
- rem = ktime_sub(timer->expires, timer->base->get_time());
+ rem = hrtimer_expires_remaining(timer);
if (rem.tv64 <= 0)
return 0;
rmt = ktime_to_timespec(rem);
@@ -1503,7 +1562,7 @@ long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
hrtimer_init_on_stack(&t.timer, restart->nanosleep.index,
HRTIMER_MODE_ABS);
- t.timer.expires.tv64 = restart->nanosleep.expires;
+ hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires);
if (do_nanosleep(&t, HRTIMER_MODE_ABS))
goto out;
@@ -1528,9 +1587,14 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
struct restart_block *restart;
struct hrtimer_sleeper t;
int ret = 0;
+ unsigned long slack;
+
+ slack = current->timer_slack_ns;
+ if (rt_task(current))
+ slack = 0;
hrtimer_init_on_stack(&t.timer, clockid, mode);
- t.timer.expires = timespec_to_ktime(*rqtp);
+ hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack);
if (do_nanosleep(&t, mode))
goto out;
@@ -1550,7 +1614,7 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
restart->fn = hrtimer_nanosleep_restart;
restart->nanosleep.index = t.timer.base->index;
restart->nanosleep.rmtp = rmtp;
- restart->nanosleep.expires = t.timer.expires.tv64;
+ restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer);
ret = -ERESTART_RESTARTBLOCK;
out:
@@ -1752,3 +1816,103 @@ void __init hrtimers_init(void)
#endif
}
+/**
+ * schedule_hrtimeout_range - sleep until timeout
+ * @expires: timeout value (ktime_t)
+ * @delta: slack in expires timeout (ktime_t)
+ * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL
+ *
+ * Make the current task sleep until the given expiry time has
+ * elapsed. The routine will return immediately unless
+ * the current task state has been set (see set_current_state()).
+ *
+ * The @delta argument gives the kernel the freedom to schedule the
+ * actual wakeup to a time that is both power and performance friendly.
+ * The kernel give the normal best effort behavior for "@expires+@delta",
+ * but may decide to fire the timer earlier, but no earlier than @expires.
+ *
+ * You can set the task state as follows -
+ *
+ * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
+ * pass before the routine returns.
+ *
+ * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
+ * delivered to the current task.
+ *
+ * The current task state is guaranteed to be TASK_RUNNING when this
+ * routine returns.
+ *
+ * Returns 0 when the timer has expired otherwise -EINTR
+ */
+int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,
+ const enum hrtimer_mode mode)
+{
+ struct hrtimer_sleeper t;
+
+ /*
+ * Optimize when a zero timeout value is given. It does not
+ * matter whether this is an absolute or a relative time.
+ */
+ if (expires && !expires->tv64) {
+ __set_current_state(TASK_RUNNING);
+ return 0;
+ }
+
+ /*
+ * A NULL parameter means "inifinte"
+ */
+ if (!expires) {
+ schedule();
+ __set_current_state(TASK_RUNNING);
+ return -EINTR;
+ }
+
+ hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC, mode);
+ hrtimer_set_expires_range_ns(&t.timer, *expires, delta);
+
+ hrtimer_init_sleeper(&t, current);
+
+ hrtimer_start_expires(&t.timer, mode);
+ if (!hrtimer_active(&t.timer))
+ t.task = NULL;
+
+ if (likely(t.task))
+ schedule();
+
+ hrtimer_cancel(&t.timer);
+ destroy_hrtimer_on_stack(&t.timer);
+
+ __set_current_state(TASK_RUNNING);
+
+ return !t.task ? 0 : -EINTR;
+}
+EXPORT_SYMBOL_GPL(schedule_hrtimeout_range);
+
+/**
+ * schedule_hrtimeout - sleep until timeout
+ * @expires: timeout value (ktime_t)
+ * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL
+ *
+ * Make the current task sleep until the given expiry time has
+ * elapsed. The routine will return immediately unless
+ * the current task state has been set (see set_current_state()).
+ *
+ * You can set the task state as follows -
+ *
+ * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
+ * pass before the routine returns.
+ *
+ * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
+ * delivered to the current task.
+ *
+ * The current task state is guaranteed to be TASK_RUNNING when this
+ * routine returns.
+ *
+ * Returns 0 when the timer has expired otherwise -EINTR
+ */
+int __sched schedule_hrtimeout(ktime_t *expires,
+ const enum hrtimer_mode mode)
+{
+ return schedule_hrtimeout_range(expires, 0, mode);
+}
+EXPORT_SYMBOL_GPL(schedule_hrtimeout);