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authorLinus Torvalds <torvalds@linux-foundation.org>2014-01-20 11:34:26 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-20 11:34:26 -0800
commit6c6461435611e1d4843516f2d55e8316c009112e (patch)
tree2285f7ef3257dcb30342f931430ad755fc5d299b /kernel
parenta0fa1dd3cdbccec9597fe53b6177a9aa6e20f2f8 (diff)
parent00e2bcd6d35f59fce7fa0e76e24d08f74c6a8506 (diff)
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer changes from Ingo Molnar: - ARM clocksource/clockevent improvements and fixes - generic timekeeping updates: TAI fixes/improvements, cleanups - Posix cpu timer cleanups and improvements - dynticks updates: full dynticks bugfixes, optimizations and cleanups * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits) clocksource: Timer-sun5i: Switch to sched_clock_register() timekeeping: Remove comment that's mostly out of date rtc-cmos: Add an alarm disable quirk timekeeper: fix comment typo for tk_setup_internals() timekeeping: Fix missing timekeeping_update in suspend path timekeeping: Fix CLOCK_TAI timer/nanosleep delays tick/timekeeping: Call update_wall_time outside the jiffies lock timekeeping: Avoid possible deadlock from clock_was_set_delayed timekeeping: Fix potential lost pv notification of time change timekeeping: Fix lost updates to tai adjustment clocksource: sh_cmt: Add clk_prepare/unprepare support clocksource: bcm_kona_timer: Remove unused bcm_timer_ids clocksource: vt8500: Remove deprecated IRQF_DISABLED clocksource: tegra: Remove deprecated IRQF_DISABLED clocksource: misc drivers: Remove deprecated IRQF_DISABLED clocksource: sh_mtu2: Remove unnecessary platform_set_drvdata() clocksource: sh_tmu: Remove unnecessary platform_set_drvdata() clocksource: armada-370-xp: Enable timer divider only when needed clocksource: clksrc-of: Warn if no clock sources are found clocksource: orion: Switch to sched_clock_register() ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/context_tracking.c8
-rw-r--r--kernel/posix-cpu-timers.c327
-rw-r--r--kernel/softirq.c4
-rw-r--r--kernel/time/tick-broadcast.c6
-rw-r--r--kernel/time/tick-common.c1
-rw-r--r--kernel/time/tick-internal.h5
-rw-r--r--kernel/time/tick-sched.c40
-rw-r--r--kernel/time/timekeeping.c53
8 files changed, 190 insertions, 254 deletions
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index e5f3917aa05b..6cb20d2e7ee0 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -53,10 +53,10 @@ void context_tracking_user_enter(void)
/*
* Repeat the user_enter() check here because some archs may be calling
* this from asm and if no CPU needs context tracking, they shouldn't
- * go further. Repeat the check here until they support the static key
- * check.
+ * go further. Repeat the check here until they support the inline static
+ * key check.
*/
- if (!static_key_false(&context_tracking_enabled))
+ if (!context_tracking_is_enabled())
return;
/*
@@ -160,7 +160,7 @@ void context_tracking_user_exit(void)
{
unsigned long flags;
- if (!static_key_false(&context_tracking_enabled))
+ if (!context_tracking_is_enabled())
return;
if (in_interrupt())
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index c7f31aa272f7..3b8946416a5f 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -233,7 +233,8 @@ void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
/*
* Sample a process (thread group) clock for the given group_leader task.
- * Must be called with tasklist_lock held for reading.
+ * Must be called with task sighand lock held for safe while_each_thread()
+ * traversal.
*/
static int cpu_clock_sample_group(const clockid_t which_clock,
struct task_struct *p,
@@ -260,30 +261,53 @@ static int cpu_clock_sample_group(const clockid_t which_clock,
return 0;
}
+static int posix_cpu_clock_get_task(struct task_struct *tsk,
+ const clockid_t which_clock,
+ struct timespec *tp)
+{
+ int err = -EINVAL;
+ unsigned long long rtn;
+
+ if (CPUCLOCK_PERTHREAD(which_clock)) {
+ if (same_thread_group(tsk, current))
+ err = cpu_clock_sample(which_clock, tsk, &rtn);
+ } else {
+ unsigned long flags;
+ struct sighand_struct *sighand;
+
+ /*
+ * while_each_thread() is not yet entirely RCU safe,
+ * keep locking the group while sampling process
+ * clock for now.
+ */
+ sighand = lock_task_sighand(tsk, &flags);
+ if (!sighand)
+ return err;
+
+ if (tsk == current || thread_group_leader(tsk))
+ err = cpu_clock_sample_group(which_clock, tsk, &rtn);
+
+ unlock_task_sighand(tsk, &flags);
+ }
+
+ if (!err)
+ sample_to_timespec(which_clock, rtn, tp);
+
+ return err;
+}
+
static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
{
const pid_t pid = CPUCLOCK_PID(which_clock);
- int error = -EINVAL;
- unsigned long long rtn;
+ int err = -EINVAL;
if (pid == 0) {
/*
* Special case constant value for our own clocks.
* We don't have to do any lookup to find ourselves.
*/
- if (CPUCLOCK_PERTHREAD(which_clock)) {
- /*
- * Sampling just ourselves we can do with no locking.
- */
- error = cpu_clock_sample(which_clock,
- current, &rtn);
- } else {
- read_lock(&tasklist_lock);
- error = cpu_clock_sample_group(which_clock,
- current, &rtn);
- read_unlock(&tasklist_lock);
- }
+ err = posix_cpu_clock_get_task(current, which_clock, tp);
} else {
/*
* Find the given PID, and validate that the caller
@@ -292,29 +316,12 @@ static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp)
struct task_struct *p;
rcu_read_lock();
p = find_task_by_vpid(pid);
- if (p) {
- if (CPUCLOCK_PERTHREAD(which_clock)) {
- if (same_thread_group(p, current)) {
- error = cpu_clock_sample(which_clock,
- p, &rtn);
- }
- } else {
- read_lock(&tasklist_lock);
- if (thread_group_leader(p) && p->sighand) {
- error =
- cpu_clock_sample_group(which_clock,
- p, &rtn);
- }
- read_unlock(&tasklist_lock);
- }
- }
+ if (p)
+ err = posix_cpu_clock_get_task(p, which_clock, tp);
rcu_read_unlock();
}
- if (error)
- return error;
- sample_to_timespec(which_clock, rtn, tp);
- return 0;
+ return err;
}
@@ -371,36 +378,40 @@ static int posix_cpu_timer_create(struct k_itimer *new_timer)
*/
static int posix_cpu_timer_del(struct k_itimer *timer)
{
- struct task_struct *p = timer->it.cpu.task;
int ret = 0;
+ unsigned long flags;
+ struct sighand_struct *sighand;
+ struct task_struct *p = timer->it.cpu.task;
- if (likely(p != NULL)) {
- read_lock(&tasklist_lock);
- if (unlikely(p->sighand == NULL)) {
- /*
- * We raced with the reaping of the task.
- * The deletion should have cleared us off the list.
- */
- BUG_ON(!list_empty(&timer->it.cpu.entry));
- } else {
- spin_lock(&p->sighand->siglock);
- if (timer->it.cpu.firing)
- ret = TIMER_RETRY;
- else
- list_del(&timer->it.cpu.entry);
- spin_unlock(&p->sighand->siglock);
- }
- read_unlock(&tasklist_lock);
+ WARN_ON_ONCE(p == NULL);
- if (!ret)
- put_task_struct(p);
+ /*
+ * Protect against sighand release/switch in exit/exec and process/
+ * thread timer list entry concurrent read/writes.
+ */
+ sighand = lock_task_sighand(p, &flags);
+ if (unlikely(sighand == NULL)) {
+ /*
+ * We raced with the reaping of the task.
+ * The deletion should have cleared us off the list.
+ */
+ WARN_ON_ONCE(!list_empty(&timer->it.cpu.entry));
+ } else {
+ if (timer->it.cpu.firing)
+ ret = TIMER_RETRY;
+ else
+ list_del(&timer->it.cpu.entry);
+
+ unlock_task_sighand(p, &flags);
}
+ if (!ret)
+ put_task_struct(p);
+
return ret;
}
-static void cleanup_timers_list(struct list_head *head,
- unsigned long long curr)
+static void cleanup_timers_list(struct list_head *head)
{
struct cpu_timer_list *timer, *next;
@@ -414,16 +425,11 @@ static void cleanup_timers_list(struct list_head *head,
* time for later timer_gettime calls to return.
* This must be called with the siglock held.
*/
-static void cleanup_timers(struct list_head *head,
- cputime_t utime, cputime_t stime,
- unsigned long long sum_exec_runtime)
+static void cleanup_timers(struct list_head *head)
{
-
- cputime_t ptime = utime + stime;
-
- cleanup_timers_list(head, cputime_to_expires(ptime));
- cleanup_timers_list(++head, cputime_to_expires(utime));
- cleanup_timers_list(++head, sum_exec_runtime);
+ cleanup_timers_list(head);
+ cleanup_timers_list(++head);
+ cleanup_timers_list(++head);
}
/*
@@ -433,41 +439,14 @@ static void cleanup_timers(struct list_head *head,
*/
void posix_cpu_timers_exit(struct task_struct *tsk)
{
- cputime_t utime, stime;
-
add_device_randomness((const void*) &tsk->se.sum_exec_runtime,
sizeof(unsigned long long));
- task_cputime(tsk, &utime, &stime);
- cleanup_timers(tsk->cpu_timers,
- utime, stime, tsk->se.sum_exec_runtime);
+ cleanup_timers(tsk->cpu_timers);
}
void posix_cpu_timers_exit_group(struct task_struct *tsk)
{
- struct signal_struct *const sig = tsk->signal;
- cputime_t utime, stime;
-
- task_cputime(tsk, &utime, &stime);
- cleanup_timers(tsk->signal->cpu_timers,
- utime + sig->utime, stime + sig->stime,
- tsk->se.sum_exec_runtime + sig->sum_sched_runtime);
-}
-
-static void clear_dead_task(struct k_itimer *itimer, unsigned long long now)
-{
- struct cpu_timer_list *timer = &itimer->it.cpu;
-
- /*
- * That's all for this thread or process.
- * We leave our residual in expires to be reported.
- */
- put_task_struct(timer->task);
- timer->task = NULL;
- if (timer->expires < now) {
- timer->expires = 0;
- } else {
- timer->expires -= now;
- }
+ cleanup_timers(tsk->signal->cpu_timers);
}
static inline int expires_gt(cputime_t expires, cputime_t new_exp)
@@ -477,8 +456,7 @@ static inline int expires_gt(cputime_t expires, cputime_t 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, interrupts disabled and p->sighand->siglock taken.
+ * expire later. This must be called with the sighand lock held.
*/
static void arm_timer(struct k_itimer *timer)
{
@@ -569,7 +547,8 @@ static void cpu_timer_fire(struct k_itimer *timer)
/*
* Sample a process (thread group) timer for the given group_leader task.
- * Must be called with tasklist_lock held for reading.
+ * Must be called with task sighand lock held for safe while_each_thread()
+ * traversal.
*/
static int cpu_timer_sample_group(const clockid_t which_clock,
struct task_struct *p,
@@ -608,7 +587,8 @@ static DECLARE_WORK(nohz_kick_work, nohz_kick_work_fn);
*/
static void posix_cpu_timer_kick_nohz(void)
{
- schedule_work(&nohz_kick_work);
+ if (context_tracking_is_enabled())
+ schedule_work(&nohz_kick_work);
}
bool posix_cpu_timers_can_stop_tick(struct task_struct *tsk)
@@ -631,43 +611,39 @@ static inline void posix_cpu_timer_kick_nohz(void) { }
* If we return TIMER_RETRY, it's necessary to release the timer's lock
* and try again. (This happens when the timer is in the middle of firing.)
*/
-static int posix_cpu_timer_set(struct k_itimer *timer, int flags,
+static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
struct itimerspec *new, struct itimerspec *old)
{
+ unsigned long flags;
+ struct sighand_struct *sighand;
struct task_struct *p = timer->it.cpu.task;
unsigned long long old_expires, new_expires, old_incr, val;
int ret;
- if (unlikely(p == NULL)) {
- /*
- * Timer refers to a dead task's clock.
- */
- return -ESRCH;
- }
+ WARN_ON_ONCE(p == NULL);
new_expires = timespec_to_sample(timer->it_clock, &new->it_value);
- read_lock(&tasklist_lock);
/*
- * We need the tasklist_lock to protect against reaping that
- * clears p->sighand. If p has just been reaped, we can no
+ * Protect against sighand release/switch in exit/exec and p->cpu_timers
+ * and p->signal->cpu_timers read/write in arm_timer()
+ */
+ sighand = lock_task_sighand(p, &flags);
+ /*
+ * If p has just been reaped, we can no
* longer get any information about it at all.
*/
- if (unlikely(p->sighand == NULL)) {
- read_unlock(&tasklist_lock);
- put_task_struct(p);
- timer->it.cpu.task = NULL;
+ if (unlikely(sighand == NULL)) {
return -ESRCH;
}
/*
* Disarm any old timer after extracting its expiry time.
*/
- BUG_ON(!irqs_disabled());
+ WARN_ON_ONCE(!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)) {
timer->it.cpu.firing = -1;
@@ -724,12 +700,11 @@ static 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);
+ unlock_task_sighand(p, &flags);
goto out;
}
- if (new_expires != 0 && !(flags & TIMER_ABSTIME)) {
+ if (new_expires != 0 && !(timer_flags & TIMER_ABSTIME)) {
new_expires += val;
}
@@ -743,9 +718,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int flags,
arm_timer(timer);
}
- spin_unlock(&p->sighand->siglock);
- read_unlock(&tasklist_lock);
-
+ unlock_task_sighand(p, &flags);
/*
* Install the new reload setting, and
* set up the signal and overrun bookkeeping.
@@ -787,7 +760,8 @@ static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
{
unsigned long long now;
struct task_struct *p = timer->it.cpu.task;
- int clear_dead;
+
+ WARN_ON_ONCE(p == NULL);
/*
* Easy part: convert the reload time.
@@ -800,52 +774,34 @@ static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
return;
}
- if (unlikely(p == NULL)) {
- /*
- * This task already died and the timer will never fire.
- * In this case, expires is actually the dead value.
- */
- dead:
- sample_to_timespec(timer->it_clock, timer->it.cpu.expires,
- &itp->it_value);
- return;
- }
-
/*
* Sample the clock to take the difference with the expiry time.
*/
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
cpu_clock_sample(timer->it_clock, p, &now);
- clear_dead = p->exit_state;
} else {
- read_lock(&tasklist_lock);
- if (unlikely(p->sighand == NULL)) {
+ struct sighand_struct *sighand;
+ unsigned long flags;
+
+ /*
+ * Protect against sighand release/switch in exit/exec and
+ * also make timer sampling safe if it ends up calling
+ * thread_group_cputime().
+ */
+ sighand = lock_task_sighand(p, &flags);
+ if (unlikely(sighand == NULL)) {
/*
* The process has been reaped.
* We can't even collect a sample any more.
* Call the timer disarmed, nothing else to do.
*/
- put_task_struct(p);
- timer->it.cpu.task = NULL;
timer->it.cpu.expires = 0;
- read_unlock(&tasklist_lock);
- goto dead;
+ sample_to_timespec(timer->it_clock, timer->it.cpu.expires,
+ &itp->it_value);
} else {
cpu_timer_sample_group(timer->it_clock, p, &now);
- clear_dead = (unlikely(p->exit_state) &&
- thread_group_empty(p));
+ unlock_task_sighand(p, &flags);
}
- read_unlock(&tasklist_lock);
- }
-
- if (unlikely(clear_dead)) {
- /*
- * We've noticed that the thread is dead, but
- * not yet reaped. Take this opportunity to
- * drop our task ref.
- */
- clear_dead_task(timer, now);
- goto dead;
}
if (now < timer->it.cpu.expires) {
@@ -1059,14 +1015,12 @@ static void check_process_timers(struct task_struct *tsk,
*/
void posix_cpu_timer_schedule(struct k_itimer *timer)
{
+ struct sighand_struct *sighand;
+ unsigned long flags;
struct task_struct *p = timer->it.cpu.task;
unsigned long long now;
- if (unlikely(p == NULL))
- /*
- * The task was cleaned up already, no future firings.
- */
- goto out;
+ WARN_ON_ONCE(p == NULL);
/*
* Fetch the current sample and update the timer's expiry time.
@@ -1074,49 +1028,45 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
cpu_clock_sample(timer->it_clock, p, &now);
bump_cpu_timer(timer, now);
- if (unlikely(p->exit_state)) {
- clear_dead_task(timer, now);
+ if (unlikely(p->exit_state))
+ goto out;
+
+ /* Protect timer list r/w in arm_timer() */
+ sighand = lock_task_sighand(p, &flags);
+ if (!sighand)
goto out;
- }
- read_lock(&tasklist_lock); /* arm_timer needs it. */
- spin_lock(&p->sighand->siglock);
} else {
- read_lock(&tasklist_lock);
- if (unlikely(p->sighand == NULL)) {
+ /*
+ * Protect arm_timer() and timer sampling in case of call to
+ * thread_group_cputime().
+ */
+ sighand = lock_task_sighand(p, &flags);
+ if (unlikely(sighand == NULL)) {
/*
* The process has been reaped.
* We can't even collect a sample any more.
*/
- put_task_struct(p);
- timer->it.cpu.task = p = NULL;
timer->it.cpu.expires = 0;
- goto out_unlock;
+ goto out;
} else if (unlikely(p->exit_state) && thread_group_empty(p)) {
- /*
- * We've noticed that the thread is dead, but
- * not yet reaped. Take this opportunity to
- * drop our task ref.
- */
- cpu_timer_sample_group(timer->it_clock, p, &now);
- clear_dead_task(timer, now);
- goto out_unlock;
+ unlock_task_sighand(p, &flags);
+ /* Optimizations: if the process is dying, no need to rearm */
+ goto out;
}
- 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. */
+ /* Leave the sighand locked for the call below. */
}
/*
* Now re-arm for the new expiry time.
*/
- BUG_ON(!irqs_disabled());
+ WARN_ON_ONCE(!irqs_disabled());
arm_timer(timer);
- spin_unlock(&p->sighand->siglock);
-
-out_unlock:
- read_unlock(&tasklist_lock);
+ unlock_task_sighand(p, &flags);
+ /* Kick full dynticks CPUs in case they need to tick on the new timer */
+ posix_cpu_timer_kick_nohz();
out:
timer->it_overrun_last = timer->it_overrun;
timer->it_overrun = -1;
@@ -1200,7 +1150,7 @@ void run_posix_cpu_timers(struct task_struct *tsk)
struct k_itimer *timer, *next;
unsigned long flags;
- BUG_ON(!irqs_disabled());
+ WARN_ON_ONCE(!irqs_disabled());
/*
* The fast path checks that there are no expired thread or thread
@@ -1256,13 +1206,6 @@ void run_posix_cpu_timers(struct task_struct *tsk)
cpu_timer_fire(timer);
spin_unlock(&timer->it_lock);
}
-
- /*
- * In case some timers were rescheduled after the queue got emptied,
- * wake up full dynticks CPUs.
- */
- if (tsk->signal->cputimer.running)
- posix_cpu_timer_kick_nohz();
}
/*
@@ -1274,7 +1217,7 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
{
unsigned long long now;
- BUG_ON(clock_idx == CPUCLOCK_SCHED);
+ WARN_ON_ONCE(clock_idx == CPUCLOCK_SCHED);
cpu_timer_sample_group(clock_idx, tsk, &now);
if (oldval) {
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 8b93b3770f85..8a1e6e104892 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -319,8 +319,6 @@ asmlinkage void do_softirq(void)
*/
void irq_enter(void)
{
- int cpu = smp_processor_id();
-
rcu_irq_enter();
if (is_idle_task(current) && !in_interrupt()) {
/*
@@ -328,7 +326,7 @@ void irq_enter(void)
* here, as softirq will be serviced on return from interrupt.
*/
local_bh_disable();
- tick_check_idle(cpu);
+ tick_check_idle();
_local_bh_enable();
}
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 9532690daaa9..43780ab5e279 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -538,10 +538,10 @@ int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
* Called from irq_enter() when idle was interrupted to reenable the
* per cpu device.
*/
-void tick_check_oneshot_broadcast(int cpu)
+void tick_check_oneshot_broadcast_this_cpu(void)
{
- if (cpumask_test_cpu(cpu, tick_broadcast_oneshot_mask)) {
- struct tick_device *td = &per_cpu(tick_cpu_device, cpu);
+ if (cpumask_test_cpu(smp_processor_id(), tick_broadcast_oneshot_mask)) {
+ struct tick_device *td = &__get_cpu_var(tick_cpu_device);
/*
* We might be in the middle of switching over from
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 162b03ab0ad2..20b2fe37d105 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -85,6 +85,7 @@ static void tick_periodic(int cpu)
do_timer(1);
write_sequnlock(&jiffies_lock);
+ update_wall_time();
}
update_process_times(user_mode(get_irq_regs()));
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
index 18e71f7fbc2a..8329669b51ec 100644
--- a/kernel/time/tick-internal.h
+++ b/kernel/time/tick-internal.h
@@ -51,7 +51,7 @@ extern void tick_broadcast_switch_to_oneshot(void);
extern void tick_shutdown_broadcast_oneshot(unsigned int *cpup);
extern int tick_resume_broadcast_oneshot(struct clock_event_device *bc);
extern int tick_broadcast_oneshot_active(void);
-extern void tick_check_oneshot_broadcast(int cpu);
+extern void tick_check_oneshot_broadcast_this_cpu(void);
bool tick_broadcast_oneshot_available(void);
# else /* BROADCAST */
static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
@@ -62,7 +62,7 @@ static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
static inline void tick_broadcast_switch_to_oneshot(void) { }
static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
static inline int tick_broadcast_oneshot_active(void) { return 0; }
-static inline void tick_check_oneshot_broadcast(int cpu) { }
+static inline void tick_check_oneshot_broadcast_this_cpu(void) { }
static inline bool tick_broadcast_oneshot_available(void) { return true; }
# endif /* !BROADCAST */
@@ -155,3 +155,4 @@ static inline int tick_device_is_functional(struct clock_event_device *dev)
#endif
extern void do_timer(unsigned long ticks);
+extern void update_wall_time(void);
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index c833249ab0fb..08cb0c3b8ccb 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -86,6 +86,7 @@ static void tick_do_update_jiffies64(ktime_t now)
tick_next_period = ktime_add(last_jiffies_update, tick_period);
}
write_sequnlock(&jiffies_lock);
+ update_wall_time();
}
/*
@@ -391,11 +392,9 @@ __setup("nohz=", setup_tick_nohz);
*/
static void tick_nohz_update_jiffies(ktime_t now)
{
- int cpu = smp_processor_id();
- struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
unsigned long flags;
- ts->idle_waketime = now;
+ __this_cpu_write(tick_cpu_sched.idle_waketime, now);
local_irq_save(flags);
tick_do_update_jiffies64(now);
@@ -426,17 +425,15 @@ update_ts_time_stats(int cpu, struct tick_sched *ts, ktime_t now, u64 *last_upda
}
-static void tick_nohz_stop_idle(int cpu, ktime_t now)
+static void tick_nohz_stop_idle(struct tick_sched *ts, ktime_t now)
{
- struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
-
- update_ts_time_stats(cpu, ts, now, NULL);
+ update_ts_time_stats(smp_processor_id(), ts, now, NULL);
ts->idle_active = 0;
sched_clock_idle_wakeup_event(0);
}
-static ktime_t tick_nohz_start_idle(int cpu, struct tick_sched *ts)
+static ktime_t tick_nohz_start_idle(struct tick_sched *ts)
{
ktime_t now = ktime_get();
@@ -754,7 +751,7 @@ static void __tick_nohz_idle_enter(struct tick_sched *ts)
ktime_t now, expires;
int cpu = smp_processor_id();
- now = tick_nohz_start_idle(cpu, ts);
+ now = tick_nohz_start_idle(ts);
if (can_stop_idle_tick(cpu, ts)) {
int was_stopped = ts->tick_stopped;
@@ -911,8 +908,7 @@ static void tick_nohz_account_idle_ticks(struct tick_sched *ts)
*/
void tick_nohz_idle_exit(void)
{
- int cpu = smp_processor_id();
- struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+ struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
ktime_t now;
local_irq_disable();
@@ -925,7 +921,7 @@ void tick_nohz_idle_exit(void)
now = ktime_get();
if (ts->idle_active)
- tick_nohz_stop_idle(cpu, now);
+ tick_nohz_stop_idle(ts, now);
if (ts->tick_stopped) {
tick_nohz_restart_sched_tick(ts, now);
@@ -1009,12 +1005,10 @@ static void tick_nohz_switch_to_nohz(void)
* timer and do not touch the other magic bits which need to be done
* when idle is left.
*/
-static void tick_nohz_kick_tick(int cpu, ktime_t now)
+static void tick_nohz_kick_tick(struct tick_sched *ts, ktime_t now)
{
#if 0
/* Switch back to 2.6.27 behaviour */
-
- struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
ktime_t delta;
/*
@@ -1029,36 +1023,36 @@ static void tick_nohz_kick_tick(int cpu, ktime_t now)
#endif
}
-static inline void tick_check_nohz(int cpu)
+static inline void tick_check_nohz_this_cpu(void)
{
- struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+ struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
ktime_t now;
if (!ts->idle_active && !ts->tick_stopped)
return;
now = ktime_get();
if (ts->idle_active)
- tick_nohz_stop_idle(cpu, now);
+ tick_nohz_stop_idle(ts, now);
if (ts->tick_stopped) {
tick_nohz_update_jiffies(now);
- tick_nohz_kick_tick(cpu, now);
+ tick_nohz_kick_tick(ts, now);
}
}
#else
static inline void tick_nohz_switch_to_nohz(void) { }
-static inline void tick_check_nohz(int cpu) { }
+static inline void tick_check_nohz_this_cpu(void) { }
#endif /* CONFIG_NO_HZ_COMMON */
/*
* Called from irq_enter to notify about the possible interruption of idle()
*/
-void tick_check_idle(int cpu)
+void tick_check_idle(void)
{
- tick_check_oneshot_broadcast(cpu);
- tick_check_nohz(cpu);
+ tick_check_oneshot_broadcast_this_cpu();
+ tick_check_nohz_this_cpu();
}
/*
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 87b4f00284c9..0aa4ce81bc16 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -77,7 +77,7 @@ static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec wtm)
tk->wall_to_monotonic = wtm;
set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec);
tk->offs_real = timespec_to_ktime(tmp);
- tk->offs_tai = ktime_sub(tk->offs_real, ktime_set(tk->tai_offset, 0));
+ tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tk->tai_offset, 0));
}
static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t)
@@ -90,8 +90,9 @@ static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t)
}
/**
- * timekeeper_setup_internals - Set up internals to use clocksource clock.
+ * tk_setup_internals - Set up internals to use clocksource clock.
*
+ * @tk: The target timekeeper to setup.
* @clock: Pointer to clocksource.
*
* Calculates a fixed cycle/nsec interval for a given clocksource/adjustment
@@ -595,7 +596,7 @@ s32 timekeeping_get_tai_offset(void)
static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset)
{
tk->tai_offset = tai_offset;
- tk->offs_tai = ktime_sub(tk->offs_real, ktime_set(tai_offset, 0));
+ tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tai_offset, 0));
}
/**
@@ -610,6 +611,7 @@ void timekeeping_set_tai_offset(s32 tai_offset)
raw_spin_lock_irqsave(&timekeeper_lock, flags);
write_seqcount_begin(&timekeeper_seq);
__timekeeping_set_tai_offset(tk, tai_offset);
+ timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
write_seqcount_end(&timekeeper_seq);
raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
clock_was_set();
@@ -1023,6 +1025,8 @@ static int timekeeping_suspend(void)
timekeeping_suspend_time =
timespec_add(timekeeping_suspend_time, delta_delta);
}
+
+ timekeeping_update(tk, TK_MIRROR);
write_seqcount_end(&timekeeper_seq);
raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
@@ -1130,16 +1134,6 @@ static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
* we can adjust by 1.
*/
error >>= 2;
- /*
- * XXX - In update_wall_time, we round up to the next
- * nanosecond, and store the amount rounded up into
- * the error. This causes the likely below to be unlikely.
- *
- * The proper fix is to avoid rounding up by using
- * the high precision tk->xtime_nsec instead of
- * xtime.tv_nsec everywhere. Fixing this will take some
- * time.
- */
if (likely(error <= interval))
adj = 1;
else
@@ -1255,7 +1249,7 @@ out_adjust:
static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk)
{
u64 nsecps = (u64)NSEC_PER_SEC << tk->shift;
- unsigned int action = 0;
+ unsigned int clock_set = 0;
while (tk->xtime_nsec >= nsecps) {
int leap;
@@ -1277,11 +1271,10 @@ static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk)
__timekeeping_set_tai_offset(tk, tk->tai_offset - leap);
- clock_was_set_delayed();
- action = TK_CLOCK_WAS_SET;
+ clock_set = TK_CLOCK_WAS_SET;
}
}
- return action;
+ return clock_set;
}
/**
@@ -1294,7 +1287,8 @@ static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk)
* Returns the unconsumed cycles.
*/
static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
- u32 shift)
+ u32 shift,
+ unsigned int *clock_set)
{
cycle_t interval = tk->cycle_interval << shift;
u64 raw_nsecs;
@@ -1308,7 +1302,7 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
tk->cycle_last += interval;
tk->xtime_nsec += tk->xtime_interval << shift;
- accumulate_nsecs_to_secs(tk);
+ *clock_set |= accumulate_nsecs_to_secs(tk);
/* Accumulate raw time */
raw_nsecs = (u64)tk->raw_interval << shift;
@@ -1359,14 +1353,14 @@ static inline void old_vsyscall_fixup(struct timekeeper *tk)
* update_wall_time - Uses the current clocksource to increment the wall time
*
*/
-static void update_wall_time(void)
+void update_wall_time(void)
{
struct clocksource *clock;
struct timekeeper *real_tk = &timekeeper;
struct timekeeper *tk = &shadow_timekeeper;
cycle_t offset;
int shift = 0, maxshift;
- unsigned int action;
+ unsigned int clock_set = 0;
unsigned long flags;
raw_spin_lock_irqsave(&timekeeper_lock, flags);
@@ -1401,7 +1395,8 @@ static void update_wall_time(void)
maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1;
shift = min(shift, maxshift);
while (offset >= tk->cycle_interval) {
- offset = logarithmic_accumulation(tk, offset, shift);
+ offset = logarithmic_accumulation(tk, offset, shift,
+ &clock_set);
if (offset < tk->cycle_interval<<shift)
shift--;
}
@@ -1419,7 +1414,7 @@ static void update_wall_time(void)
* Finally, make sure that after the rounding
* xtime_nsec isn't larger than NSEC_PER_SEC
*/
- action = accumulate_nsecs_to_secs(tk);
+ clock_set |= accumulate_nsecs_to_secs(tk);
write_seqcount_begin(&timekeeper_seq);
/* Update clock->cycle_last with the new value */
@@ -1435,10 +1430,12 @@ static void update_wall_time(void)
* updating.
*/
memcpy(real_tk, tk, sizeof(*tk));
- timekeeping_update(real_tk, action);
+ timekeeping_update(real_tk, clock_set);
write_seqcount_end(&timekeeper_seq);
out:
raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+ if (clock_set)
+ clock_was_set();
}
/**
@@ -1583,7 +1580,6 @@ struct timespec get_monotonic_coarse(void)
void do_timer(unsigned long ticks)
{
jiffies_64 += ticks;
- update_wall_time();
calc_global_load(ticks);
}
@@ -1698,12 +1694,14 @@ int do_adjtimex(struct timex *txc)
if (tai != orig_tai) {
__timekeeping_set_tai_offset(tk, tai);
- update_pvclock_gtod(tk, true);
- clock_was_set_delayed();
+ timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
}
write_seqcount_end(&timekeeper_seq);
raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+ if (tai != orig_tai)
+ clock_was_set();
+
ntp_notify_cmos_timer();
return ret;
@@ -1739,4 +1737,5 @@ void xtime_update(unsigned long ticks)
write_seqlock(&jiffies_lock);
do_timer(ticks);
write_sequnlock(&jiffies_lock);
+ update_wall_time();
}

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