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authorLinus Torvalds <torvalds@linux-foundation.org>2010-05-19 17:11:10 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-19 17:11:10 -0700
commit164d44fd92e79d5bce54d0d62df9f856f7b23925 (patch)
tree9f21607849b7e684b255578ffdf41951bc31787e /kernel
parent5bfec46baa3a752393433b8d89d3b2c70820f61d (diff)
parentd7e81c269db899b800e0963dc4aceece1f82a680 (diff)
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: clocksource: Add clocksource_register_hz/khz interface posix-cpu-timers: Optimize run_posix_cpu_timers() time: Remove xtime_cache mqueue: Convert message queue timeout to use hrtimers hrtimers: Provide schedule_hrtimeout for CLOCK_REALTIME timers: Introduce the concept of timer slack for legacy timers ntp: Remove tickadj ntp: Make time_adjust static time: Add xtime, wall_to_monotonic to feature-removal-schedule timer: Try to survive timer callback preempt_count leak timer: Split out timer function call timer: Print function name for timer callbacks modifying preemption count time: Clean up warp_clock() cpu-timers: Avoid iterating over all threads in fastpath_timer_check() cpu-timers: Change SIGEV_NONE timer implementation cpu-timers: Return correct previous timer reload value cpu-timers: Cleanup arm_timer() cpu-timers: Simplify RLIMIT_CPU handling
Diffstat (limited to 'kernel')
-rw-r--r--kernel/hrtimer.c67
-rw-r--r--kernel/posix-cpu-timers.c298
-rw-r--r--kernel/time.c11
-rw-r--r--kernel/time/clocksource.c48
-rw-r--r--kernel/time/ntp.c2
-rw-r--r--kernel/time/timekeeping.c35
-rw-r--r--kernel/timer.c137
7 files changed, 312 insertions, 286 deletions
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 0086628b6e97..b9b134b35088 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -1749,35 +1749,15 @@ void __init hrtimers_init(void)
}
/**
- * schedule_hrtimeout_range - sleep until timeout
+ * schedule_hrtimeout_range_clock - 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
+ * @clock: timer clock, CLOCK_MONOTONIC or CLOCK_REALTIME
*/
-int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,
- const enum hrtimer_mode mode)
+int __sched
+schedule_hrtimeout_range_clock(ktime_t *expires, unsigned long delta,
+ const enum hrtimer_mode mode, int clock)
{
struct hrtimer_sleeper t;
@@ -1799,7 +1779,7 @@ int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,
return -EINTR;
}
- hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC, mode);
+ hrtimer_init_on_stack(&t.timer, clock, mode);
hrtimer_set_expires_range_ns(&t.timer, *expires, delta);
hrtimer_init_sleeper(&t, current);
@@ -1818,6 +1798,41 @@ int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,
return !t.task ? 0 : -EINTR;
}
+
+/**
+ * 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)
+{
+ return schedule_hrtimeout_range_clock(expires, delta, mode,
+ CLOCK_MONOTONIC);
+}
EXPORT_SYMBOL_GPL(schedule_hrtimeout_range);
/**
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index bc7704b3a443..00bb252f29a2 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -11,19 +11,18 @@
#include <trace/events/timer.h>
/*
- * Called after updating RLIMIT_CPU to set timer expiration if necessary.
+ * Called after updating RLIMIT_CPU to run cpu timer and update
+ * tsk->signal->cputime_expires expiration cache if necessary. Needs
+ * siglock protection since other code may update expiration cache as
+ * well.
*/
void update_rlimit_cpu(unsigned long rlim_new)
{
cputime_t cputime = secs_to_cputime(rlim_new);
- struct signal_struct *const sig = current->signal;
- if (cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) ||
- cputime_gt(sig->it[CPUCLOCK_PROF].expires, cputime)) {
- spin_lock_irq(&current->sighand->siglock);
- set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL);
- spin_unlock_irq(&current->sighand->siglock);
- }
+ spin_lock_irq(&current->sighand->siglock);
+ set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL);
+ spin_unlock_irq(&current->sighand->siglock);
}
static int check_clock(const clockid_t which_clock)
@@ -548,111 +547,62 @@ static inline int expires_gt(cputime_t expires, cputime_t new_exp)
cputime_gt(expires, new_exp);
}
-static inline int expires_le(cputime_t expires, cputime_t new_exp)
-{
- return !cputime_eq(expires, cputime_zero) &&
- cputime_le(expires, new_exp);
-}
/*
* Insert the timer on the appropriate list before any timers that
* expire later. This must be called with the tasklist_lock held
- * for reading, and interrupts disabled.
+ * for reading, interrupts disabled and p->sighand->siglock taken.
*/
-static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
+static void arm_timer(struct k_itimer *timer)
{
struct task_struct *p = timer->it.cpu.task;
struct list_head *head, *listpos;
+ struct task_cputime *cputime_expires;
struct cpu_timer_list *const nt = &timer->it.cpu;
struct cpu_timer_list *next;
- unsigned long i;
- head = (CPUCLOCK_PERTHREAD(timer->it_clock) ?
- p->cpu_timers : p->signal->cpu_timers);
+ if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
+ head = p->cpu_timers;
+ cputime_expires = &p->cputime_expires;
+ } else {
+ head = p->signal->cpu_timers;
+ cputime_expires = &p->signal->cputime_expires;
+ }
head += CPUCLOCK_WHICH(timer->it_clock);
- BUG_ON(!irqs_disabled());
- spin_lock(&p->sighand->siglock);
-
listpos = head;
- if (CPUCLOCK_WHICH(timer->it_clock) == CPUCLOCK_SCHED) {
- list_for_each_entry(next, head, entry) {
- if (next->expires.sched > nt->expires.sched)
- break;
- listpos = &next->entry;
- }
- } else {
- list_for_each_entry(next, head, entry) {
- if (cputime_gt(next->expires.cpu, nt->expires.cpu))
- break;
- listpos = &next->entry;
- }
+ list_for_each_entry(next, head, entry) {
+ if (cpu_time_before(timer->it_clock, nt->expires, next->expires))
+ break;
+ listpos = &next->entry;
}
list_add(&nt->entry, listpos);
if (listpos == head) {
+ union cpu_time_count *exp = &nt->expires;
+
/*
- * We are the new earliest-expiring timer.
- * If we are a thread timer, there can always
- * be a process timer telling us to stop earlier.
+ * We are the new earliest-expiring POSIX 1.b timer, hence
+ * need to update expiration cache. Take into account that
+ * for process timers we share expiration cache with itimers
+ * and RLIMIT_CPU and for thread timers with RLIMIT_RTTIME.
*/
- if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
- union cpu_time_count *exp = &nt->expires;
-
- switch (CPUCLOCK_WHICH(timer->it_clock)) {
- default:
- BUG();
- case CPUCLOCK_PROF:
- if (expires_gt(p->cputime_expires.prof_exp,
- exp->cpu))
- p->cputime_expires.prof_exp = exp->cpu;
- break;
- case CPUCLOCK_VIRT:
- if (expires_gt(p->cputime_expires.virt_exp,
- exp->cpu))
- p->cputime_expires.virt_exp = exp->cpu;
- break;
- case CPUCLOCK_SCHED:
- if (p->cputime_expires.sched_exp == 0 ||
- p->cputime_expires.sched_exp > exp->sched)
- p->cputime_expires.sched_exp =
- exp->sched;
- break;
- }
- } else {
- struct signal_struct *const sig = p->signal;
- union cpu_time_count *exp = &timer->it.cpu.expires;
-
- /*
- * For a process timer, set the cached expiration time.
- */
- switch (CPUCLOCK_WHICH(timer->it_clock)) {
- default:
- BUG();
- case CPUCLOCK_VIRT:
- if (expires_le(sig->it[CPUCLOCK_VIRT].expires,
- exp->cpu))
- break;
- sig->cputime_expires.virt_exp = exp->cpu;
- break;
- case CPUCLOCK_PROF:
- if (expires_le(sig->it[CPUCLOCK_PROF].expires,
- exp->cpu))
- break;
- i = sig->rlim[RLIMIT_CPU].rlim_cur;
- if (i != RLIM_INFINITY &&
- i <= cputime_to_secs(exp->cpu))
- break;
- sig->cputime_expires.prof_exp = exp->cpu;
- break;
- case CPUCLOCK_SCHED:
- sig->cputime_expires.sched_exp = exp->sched;
- break;
- }
+ switch (CPUCLOCK_WHICH(timer->it_clock)) {
+ case CPUCLOCK_PROF:
+ if (expires_gt(cputime_expires->prof_exp, exp->cpu))
+ cputime_expires->prof_exp = exp->cpu;
+ break;
+ case CPUCLOCK_VIRT:
+ if (expires_gt(cputime_expires->virt_exp, exp->cpu))
+ cputime_expires->virt_exp = exp->cpu;
+ break;
+ case CPUCLOCK_SCHED:
+ if (cputime_expires->sched_exp == 0 ||
+ cputime_expires->sched_exp > exp->sched)
+ cputime_expires->sched_exp = exp->sched;
+ break;
}
}
-
- spin_unlock(&p->sighand->siglock);
}
/*
@@ -660,7 +610,12 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
*/
static void cpu_timer_fire(struct k_itimer *timer)
{
- if (unlikely(timer->sigq == NULL)) {
+ if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
+ /*
+ * User don't want any signal.
+ */
+ timer->it.cpu.expires.sched = 0;
+ } else if (unlikely(timer->sigq == NULL)) {
/*
* This a special case for clock_nanosleep,
* not a normal timer from sys_timer_create.
@@ -721,7 +676,7 @@ int posix_cpu_timer_set(struct k_itimer *timer, int flags,
struct itimerspec *new, struct itimerspec *old)
{
struct task_struct *p = timer->it.cpu.task;
- union cpu_time_count old_expires, new_expires, val;
+ union cpu_time_count old_expires, new_expires, old_incr, val;
int ret;
if (unlikely(p == NULL)) {
@@ -752,6 +707,7 @@ int posix_cpu_timer_set(struct k_itimer *timer, int flags,
BUG_ON(!irqs_disabled());
ret = 0;
+ old_incr = timer->it.cpu.incr;
spin_lock(&p->sighand->siglock);
old_expires = timer->it.cpu.expires;
if (unlikely(timer->it.cpu.firing)) {
@@ -759,7 +715,6 @@ int posix_cpu_timer_set(struct k_itimer *timer, int flags,
ret = TIMER_RETRY;
} else
list_del_init(&timer->it.cpu.entry);
- spin_unlock(&p->sighand->siglock);
/*
* We need to sample the current value to convert the new
@@ -813,6 +768,7 @@ int posix_cpu_timer_set(struct k_itimer *timer, int flags,
* disable this firing since we are already reporting
* it as an overrun (thanks to bump_cpu_timer above).
*/
+ spin_unlock(&p->sighand->siglock);
read_unlock(&tasklist_lock);
goto out;
}
@@ -828,11 +784,11 @@ int posix_cpu_timer_set(struct k_itimer *timer, int flags,
*/
timer->it.cpu.expires = new_expires;
if (new_expires.sched != 0 &&
- (timer->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE &&
cpu_time_before(timer->it_clock, val, new_expires)) {
- arm_timer(timer, val);
+ arm_timer(timer);
}
+ spin_unlock(&p->sighand->siglock);
read_unlock(&tasklist_lock);
/*
@@ -853,7 +809,6 @@ int posix_cpu_timer_set(struct k_itimer *timer, int flags,
timer->it_overrun = -1;
if (new_expires.sched != 0 &&
- (timer->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE &&
!cpu_time_before(timer->it_clock, val, new_expires)) {
/*
* The designated time already passed, so we notify
@@ -867,7 +822,7 @@ int posix_cpu_timer_set(struct k_itimer *timer, int flags,
out:
if (old) {
sample_to_timespec(timer->it_clock,
- timer->it.cpu.incr, &old->it_interval);
+ old_incr, &old->it_interval);
}
return ret;
}
@@ -927,25 +882,6 @@ void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
read_unlock(&tasklist_lock);
}
- if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) {
- if (timer->it.cpu.incr.sched == 0 &&
- cpu_time_before(timer->it_clock,
- timer->it.cpu.expires, now)) {
- /*
- * Do-nothing timer expired and has no reload,
- * so it's as if it was never set.
- */
- timer->it.cpu.expires.sched = 0;
- itp->it_value.tv_sec = itp->it_value.tv_nsec = 0;
- return;
- }
- /*
- * Account for any expirations and reloads that should
- * have happened.
- */
- bump_cpu_timer(timer, now);
- }
-
if (unlikely(clear_dead)) {
/*
* We've noticed that the thread is dead, but
@@ -1066,16 +1002,9 @@ static void stop_process_timers(struct signal_struct *sig)
struct thread_group_cputimer *cputimer = &sig->cputimer;
unsigned long flags;
- if (!cputimer->running)
- return;
-
spin_lock_irqsave(&cputimer->lock, flags);
cputimer->running = 0;
spin_unlock_irqrestore(&cputimer->lock, flags);
-
- sig->cputime_expires.prof_exp = cputime_zero;
- sig->cputime_expires.virt_exp = cputime_zero;
- sig->cputime_expires.sched_exp = 0;
}
static u32 onecputick;
@@ -1112,6 +1041,23 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
}
}
+/**
+ * task_cputime_zero - Check a task_cputime struct for all zero fields.
+ *
+ * @cputime: The struct to compare.
+ *
+ * Checks @cputime to see if all fields are zero. Returns true if all fields
+ * are zero, false if any field is nonzero.
+ */
+static inline int task_cputime_zero(const struct task_cputime *cputime)
+{
+ if (cputime_eq(cputime->utime, cputime_zero) &&
+ cputime_eq(cputime->stime, cputime_zero) &&
+ cputime->sum_exec_runtime == 0)
+ return 1;
+ return 0;
+}
+
/*
* Check for any per-thread CPU timers that have fired and move them
* off the tsk->*_timers list onto the firing list. Per-thread timers
@@ -1129,19 +1075,6 @@ static void check_process_timers(struct task_struct *tsk,
unsigned long soft;
/*
- * Don't sample the current process CPU clocks if there are no timers.
- */
- if (list_empty(&timers[CPUCLOCK_PROF]) &&
- cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) &&
- sig->rlim[RLIMIT_CPU].rlim_cur == RLIM_INFINITY &&
- list_empty(&timers[CPUCLOCK_VIRT]) &&
- cputime_eq(sig->it[CPUCLOCK_VIRT].expires, cputime_zero) &&
- list_empty(&timers[CPUCLOCK_SCHED])) {
- stop_process_timers(sig);
- return;
- }
-
- /*
* Collect the current process totals.
*/
thread_group_cputimer(tsk, &cputime);
@@ -1230,18 +1163,11 @@ static void check_process_timers(struct task_struct *tsk,
}
}
- if (!cputime_eq(prof_expires, cputime_zero) &&
- (cputime_eq(sig->cputime_expires.prof_exp, cputime_zero) ||
- cputime_gt(sig->cputime_expires.prof_exp, prof_expires)))
- sig->cputime_expires.prof_exp = prof_expires;
- if (!cputime_eq(virt_expires, cputime_zero) &&
- (cputime_eq(sig->cputime_expires.virt_exp, cputime_zero) ||
- cputime_gt(sig->cputime_expires.virt_exp, virt_expires)))
- sig->cputime_expires.virt_exp = virt_expires;
- if (sched_expires != 0 &&
- (sig->cputime_expires.sched_exp == 0 ||
- sig->cputime_expires.sched_exp > sched_expires))
- sig->cputime_expires.sched_exp = sched_expires;
+ sig->cputime_expires.prof_exp = prof_expires;
+ sig->cputime_expires.virt_exp = virt_expires;
+ sig->cputime_expires.sched_exp = sched_expires;
+ if (task_cputime_zero(&sig->cputime_expires))
+ stop_process_timers(sig);
}
/*
@@ -1270,6 +1196,7 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
goto out;
}
read_lock(&tasklist_lock); /* arm_timer needs it. */
+ spin_lock(&p->sighand->siglock);
} else {
read_lock(&tasklist_lock);
if (unlikely(p->signal == NULL)) {
@@ -1290,6 +1217,7 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
clear_dead_task(timer, now);
goto out_unlock;
}
+ spin_lock(&p->sighand->siglock);
cpu_timer_sample_group(timer->it_clock, p, &now);
bump_cpu_timer(timer, now);
/* Leave the tasklist_lock locked for the call below. */
@@ -1298,7 +1226,9 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
/*
* Now re-arm for the new expiry time.
*/
- arm_timer(timer, now);
+ BUG_ON(!irqs_disabled());
+ arm_timer(timer);
+ spin_unlock(&p->sighand->siglock);
out_unlock:
read_unlock(&tasklist_lock);
@@ -1310,23 +1240,6 @@ out:
}
/**
- * task_cputime_zero - Check a task_cputime struct for all zero fields.
- *
- * @cputime: The struct to compare.
- *
- * Checks @cputime to see if all fields are zero. Returns true if all fields
- * are zero, false if any field is nonzero.
- */
-static inline int task_cputime_zero(const struct task_cputime *cputime)
-{
- if (cputime_eq(cputime->utime, cputime_zero) &&
- cputime_eq(cputime->stime, cputime_zero) &&
- cputime->sum_exec_runtime == 0)
- return 1;
- return 0;
-}
-
-/**
* task_cputime_expired - Compare two task_cputime entities.
*
* @sample: The task_cputime structure to be checked for expiration.
@@ -1382,7 +1295,7 @@ static inline int fastpath_timer_check(struct task_struct *tsk)
}
sig = tsk->signal;
- if (!task_cputime_zero(&sig->cputime_expires)) {
+ if (sig->cputimer.running) {
struct task_cputime group_sample;
thread_group_cputimer(tsk, &group_sample);
@@ -1390,7 +1303,7 @@ static inline int fastpath_timer_check(struct task_struct *tsk)
return 1;
}
- return sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY;
+ return 0;
}
/*
@@ -1419,7 +1332,12 @@ void run_posix_cpu_timers(struct task_struct *tsk)
* put them on the firing list.
*/
check_thread_timers(tsk, &firing);
- check_process_timers(tsk, &firing);
+ /*
+ * If there are any active process wide timers (POSIX 1.b, itimers,
+ * RLIMIT_CPU) cputimer must be running.
+ */
+ if (tsk->signal->cputimer.running)
+ check_process_timers(tsk, &firing);
/*
* We must release these locks before taking any timer's lock.
@@ -1456,21 +1374,23 @@ void run_posix_cpu_timers(struct task_struct *tsk)
}
/*
- * Set one of the process-wide special case CPU timers.
+ * Set one of the process-wide special case CPU timers or RLIMIT_CPU.
* The tsk->sighand->siglock must be held by the caller.
- * The *newval argument is relative and we update it to be absolute, *oldval
- * is absolute and we update it to be relative.
*/
void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
cputime_t *newval, cputime_t *oldval)
{
union cpu_time_count now;
- struct list_head *head;
BUG_ON(clock_idx == CPUCLOCK_SCHED);
cpu_timer_sample_group(clock_idx, tsk, &now);
if (oldval) {
+ /*
+ * We are setting itimer. The *oldval is absolute and we update
+ * it to be relative, *newval argument is relative and we update
+ * it to be absolute.
+ */
if (!cputime_eq(*oldval, cputime_zero)) {
if (cputime_le(*oldval, now.cpu)) {
/* Just about to fire. */
@@ -1483,33 +1403,21 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
if (cputime_eq(*newval, cputime_zero))
return;
*newval = cputime_add(*newval, now.cpu);
-
- /*
- * If the RLIMIT_CPU timer will expire before the
- * ITIMER_PROF timer, we have nothing else to do.
- */
- if (tsk->signal->rlim[RLIMIT_CPU].rlim_cur
- < cputime_to_secs(*newval))
- return;
}
/*
- * Check whether there are any process timers already set to fire
- * before this one. If so, we don't have anything more to do.
+ * Update expiration cache if we are the earliest timer, or eventually
+ * RLIMIT_CPU limit is earlier than prof_exp cpu timer expire.
*/
- head = &tsk->signal->cpu_timers[clock_idx];
- if (list_empty(head) ||
- cputime_ge(list_first_entry(head,
- struct cpu_timer_list, entry)->expires.cpu,
- *newval)) {
- switch (clock_idx) {
- case CPUCLOCK_PROF:
+ switch (clock_idx) {
+ case CPUCLOCK_PROF:
+ if (expires_gt(tsk->signal->cputime_expires.prof_exp, *newval))
tsk->signal->cputime_expires.prof_exp = *newval;
- break;
- case CPUCLOCK_VIRT:
+ break;
+ case CPUCLOCK_VIRT:
+ if (expires_gt(tsk->signal->cputime_expires.virt_exp, *newval))
tsk->signal->cputime_expires.virt_exp = *newval;
- break;
- }
+ break;
}
}
diff --git a/kernel/time.c b/kernel/time.c
index 656dccfe1cbb..50612faa9baf 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -132,12 +132,11 @@ SYSCALL_DEFINE2(gettimeofday, struct timeval __user *, tv,
*/
static inline void warp_clock(void)
{
- write_seqlock_irq(&xtime_lock);
- wall_to_monotonic.tv_sec -= sys_tz.tz_minuteswest * 60;
- xtime.tv_sec += sys_tz.tz_minuteswest * 60;
- update_xtime_cache(0);
- write_sequnlock_irq(&xtime_lock);
- clock_was_set();
+ struct timespec delta, adjust;
+ delta.tv_sec = sys_tz.tz_minuteswest * 60;
+ delta.tv_nsec = 0;
+ adjust = timespec_add_safe(current_kernel_time(), delta);
+ do_settimeofday(&adjust);
}
/*
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 1f5dde637457..f08e99c1d561 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -625,6 +625,54 @@ static void clocksource_enqueue(struct clocksource *cs)
list_add(&cs->list, entry);
}
+
+/*
+ * Maximum time we expect to go between ticks. This includes idle
+ * tickless time. It provides the trade off between selecting a
+ * mult/shift pair that is very precise but can only handle a short
+ * period of time, vs. a mult/shift pair that can handle long periods
+ * of time but isn't as precise.
+ *
+ * This is a subsystem constant, and actual hardware limitations
+ * may override it (ie: clocksources that wrap every 3 seconds).
+ */
+#define MAX_UPDATE_LENGTH 5 /* Seconds */
+
+/**
+ * __clocksource_register_scale - Used to install new clocksources
+ * @t: clocksource to be registered
+ * @scale: Scale factor multiplied against freq to get clocksource hz
+ * @freq: clocksource frequency (cycles per second) divided by scale
+ *
+ * Returns -EBUSY if registration fails, zero otherwise.
+ *
+ * This *SHOULD NOT* be called directly! Please use the
+ * clocksource_register_hz() or clocksource_register_khz helper functions.
+ */
+int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
+{
+
+ /*
+ * Ideally we want to use some of the limits used in
+ * clocksource_max_deferment, to provide a more informed
+ * MAX_UPDATE_LENGTH. But for now this just gets the
+ * register interface working properly.
+ */
+ clocks_calc_mult_shift(&cs->mult, &cs->shift, freq,
+ NSEC_PER_SEC/scale,
+ MAX_UPDATE_LENGTH*scale);
+ cs->max_idle_ns = clocksource_max_deferment(cs);
+
+ mutex_lock(&clocksource_mutex);
+ clocksource_enqueue(cs);
+ clocksource_select();
+ clocksource_enqueue_watchdog(cs);
+ mutex_unlock(&clocksource_mutex);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__clocksource_register_scale);
+
+
/**
* clocksource_register - Used to install new clocksources
* @t: clocksource to be registered
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 7c0f180d6e9d..c63116863a80 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -69,7 +69,7 @@ static s64 time_freq;
/* time at last adjustment (secs): */
static long time_reftime;
-long time_adjust;
+static long time_adjust;
/* constant (boot-param configurable) NTP tick adjustment (upscaled) */
static s64 ntp_tick_adj;
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 39f6177fafac..caf8d4d4f5c8 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -165,13 +165,6 @@ struct timespec raw_time;
/* flag for if timekeeping is suspended */
int __read_mostly timekeeping_suspended;
-static struct timespec xtime_cache __attribute__ ((aligned (16)));
-void update_xtime_cache(u64 nsec)
-{
- xtime_cache = xtime;
- timespec_add_ns(&xtime_cache, nsec);
-}
-
/* must hold xtime_lock */
void timekeeping_leap_insert(int leapsecond)
{
@@ -332,8 +325,6 @@ int do_settimeofday(struct timespec *tv)
xtime = *tv;
- update_xtime_cache(0);
-
timekeeper.ntp_error = 0;
ntp_clear();
@@ -559,7 +550,6 @@ void __init timekeeping_init(void)
}
set_normalized_timespec(&wall_to_monotonic,
-boot.tv_sec, -boot.tv_nsec);
- update_xtime_cache(0);
total_sleep_time.tv_sec = 0;
total_sleep_time.tv_nsec = 0;
write_sequnlock_irqrestore(&xtime_lock, flags);
@@ -593,7 +583,6 @@ static int timekeeping_resume(struct sys_device *dev)
wall_to_monotonic = timespec_sub(wall_to_monotonic, ts);
total_sleep_time = timespec_add_safe(total_sleep_time, ts);
}
- update_xtime_cache(0);
/* re-base the last cycle value */
timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);
timekeeper.ntp_error = 0;
@@ -788,7 +777,6 @@ void update_wall_time(void)
{
struct clocksource *clock;
cycle_t offset;
- u64 nsecs;
int shift = 0, maxshift;
/* Make sure we're fully resumed: */
@@ -847,7 +835,9 @@ void update_wall_time(void)
timekeeper.ntp_error += neg << timekeeper.ntp_error_shift;
}
- /* store full nanoseconds into xtime after rounding it up and
+
+ /*
+ * Store full nanoseconds into xtime after rounding it up and
* add the remainder to the error difference.
*/
xtime.tv_nsec = ((s64) timekeeper.xtime_nsec >> timekeeper.shift) + 1;
@@ -855,8 +845,15 @@ void update_wall_time(void)
timekeeper.ntp_error += timekeeper.xtime_nsec <<
timekeeper.ntp_error_shift;
- nsecs = clocksource_cyc2ns(offset, timekeeper.mult, timekeeper.shift);
- update_xtime_cache(nsecs);
+ /*
+ * Finally, make sure that after the rounding
+ * xtime.tv_nsec isn't larger then NSEC_PER_SEC
+ */
+ if (unlikely(xtime.tv_nsec >= NSEC_PER_SEC)) {
+ xtime.tv_nsec -= NSEC_PER_SEC;
+ xtime.tv_sec++;
+ second_overflow();
+ }
/* check to see if there is a new clocksource to use */
update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult);
@@ -896,13 +893,13 @@ EXPORT_SYMBOL_GPL(monotonic_to_bootbased);
unsigned long get_seconds(void)
{
- return xtime_cache.tv_sec;
+ return xtime.tv_sec;
}
EXPORT_SYMBOL(get_seconds);
struct timespec __current_kernel_time(void)
{
- return xtime_cache;
+ return xtime;
}
struct timespec current_kernel_time(void)
@@ -913,7 +910,7 @@ struct timespec current_kernel_time(void)
do {
seq = read_seqbegin(&xtime_lock);
- now = xtime_cache;
+ now = xtime;
} while (read_seqretry(&xtime_lock, seq));
return now;
@@ -928,7 +925,7 @@ struct timespec get_monotonic_coarse(void)
do {
seq = read_seqbegin(&xtime_lock);
- now = xtime_cache;
+ now = xtime;
mono = wall_to_monotonic;
} while (read_seqretry(&xtime_lock, seq));
diff --git a/kernel/timer.c b/kernel/timer.c
index aeb6a54f2771..9199f3c52215 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -319,6 +319,24 @@ unsigned long round_jiffies_up_relative(unsigned long j)
}
EXPORT_SYMBOL_GPL(round_jiffies_up_relative);
+/**
+ * set_timer_slack - set the allowed slack for a timer
+ * @slack_hz: the amount of time (in jiffies) allowed for rounding
+ *
+ * Set the amount of time, in jiffies, that a certain timer has
+ * in terms of slack. By setting this value, the timer subsystem
+ * will schedule the actual timer somewhere between
+ * the time mod_timer() asks for, and that time plus the slack.
+ *
+ * By setting the slack to -1, a percentage of the delay is used
+ * instead.
+ */
+void set_timer_slack(struct timer_list *timer, int slack_hz)
+{
+ timer->slack = slack_hz;
+}
+EXPORT_SYMBOL_GPL(set_timer_slack);
+
static inline void set_running_timer(struct tvec_base *base,
struct timer_list *timer)
@@ -550,6 +568,7 @@ static void __init_timer(struct timer_list *timer,
{
timer->entry.next = NULL;
timer->base = __raw_get_cpu_var(tvec_bases);
+ timer->slack = -1;
#ifdef CONFIG_TIMER_STATS
timer->start_site = NULL;
timer->start_pid = -1;
@@ -715,6 +734,41 @@ int mod_timer_pending(struct timer_list *timer, unsigned long expires)
}
EXPORT_SYMBOL(mod_timer_pending);
+/*
+ * Decide where to put the timer while taking the slack into account
+ *
+ * Algorithm:
+ * 1) calculate the maximum (absolute) time
+ * 2) calculate the highest bit where the expires and new max are different
+ * 3) use this bit to make a mask
+ * 4) use the bitmask to round down the maximum time, so that all last
+ * bits are zeros
+ */
+static inline
+unsigned long apply_slack(struct timer_list *timer, unsigned long expires)
+{
+ unsigned long expires_limit, mask;
+ int bit;
+
+ expires_limit = expires + timer->slack;
+
+ if (timer->slack < 0) /* auto slack: use 0.4% */
+ expires_limit = expires + (expires - jiffies)/256;
+
+ mask = expires ^ expires_limit;
+
+ if (mask == 0)
+ return expires;
+
+ bit = find_last_bit(&mask, BITS_PER_LONG);
+
+ mask = (1 << bit) - 1;
+
+ expires_limit = expires_limit & ~(mask);
+
+ return expires_limit;
+}
+
/**
* mod_timer - modify a timer's timeout
* @timer: the timer to be modified
@@ -745,6 +799,8 @@ int mod_timer(struct timer_list *timer, unsigned long expires)
if (timer_pending(timer) && timer->expires == expires)
return 1;
+ expires = apply_slack(timer, expires);
+
return __mod_timer(timer, expires, false, TIMER_NOT_PINNED);
}
EXPORT_SYMBOL(mod_timer);
@@ -955,6 +1011,47 @@ static int cascade(struct tvec_base *base, struct tvec *tv, int index)
return index;
}
+static void call_timer_fn(struct timer_list *timer, void (*fn)(unsigned long),
+ unsigned long data)
+{
+ int preempt_count = preempt_count();
+
+#ifdef CONFIG_LOCKDEP
+ /*
+ * It is permissible to free the timer from inside the
+ * function that is called from it, this we need to take into
+ * account for lockdep too. To avoid bogus "held lock freed"
+ * warnings as well as problems when looking into
+ * timer->lockdep_map, make a copy and use that here.
+ */
+ struct lockdep_map lockdep_map = timer->lockdep_map;
+#endif
+ /*
+ * Couple the lock chain with the lock chain at
+ * del_timer_sync() by acquiring the lock_map around the fn()
+ * call here and in del_timer_sync().
+ */
+ lock_map_acquire(&lockdep_map);
+
+ trace_timer_expire_entry(timer);
+ fn(data);
+ trace_timer_expire_exit(timer);
+
+ lock_map_release(&lockdep_map);
+
+ if (preempt_count != preempt_count()) {
+ WARN_ONCE(1, "timer: %pF preempt leak: %08x -> %08x\n",
+ fn, preempt_count, preempt_count());
+ /*
+ * Restore the preempt count. That gives us a decent
+ * chance to survive and extract information. If the
+ * callback kept a lock held, bad luck, but not worse
+ * than the BUG() we had.
+ */
+ preempt_count() = preempt_count;
+ }
+}
+
#define INDEX(N) ((base->timer_jiffies >> (TVR_BITS + (N) * TVN_BITS)) & TVN_MASK)
/**
@@ -998,45 +1095,7 @@ static inline void __run_timers(struct tvec_base *base)
detach_timer(timer, 1);
spin_unlock_irq(&base->lock);
- {
- int preempt_count = preempt_count();
-
-#ifdef CONFIG_LOCKDEP
- /*
- * It is permissible to free the timer from
- * inside the function that is called from
- * it, this we need to take into account for
- * lockdep too. To avoid bogus "held lock
- * freed" warnings as well as problems when
- * looking into timer->lockdep_map, make a
- * copy and use that here.
- */
- struct lockdep_map lockdep_map =
- timer->lockdep_map;
-#endif
- /*
- * Couple the lock chain with the lock chain at
- * del_timer_sync() by acquiring the lock_map
- * around the fn() call here and in
- * del_timer_sync().
- */
- lock_map_acquire(&lockdep_map);
-
- trace_timer_expire_entry(timer);
- fn(data);
- trace_timer_expire_exit(timer);
-
- lock_map_release(&lockdep_map);
-
- if (preempt_count != preempt_count()) {
- printk(KERN_ERR "huh, entered %p "
- "with preempt_count %08x, exited"
- " with %08x?\n",
- fn, preempt_count,
- preempt_count());
- BUG();
- }
- }
+ call_timer_fn(timer, fn, data);
spin_lock_irq(&base->lock);
}
}