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Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull timer core changes from Ingo Molnar:
 "Continued cleanups of the core time and NTP code, plus more nohz work
  preparing for tick-less userspace execution."

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: Rework timekeeping functions to take timekeeper ptr as argument
  time: Move xtime_nsec adjustment underflow handling timekeeping_adjust
  time: Move arch_gettimeoffset() usage into timekeeping_get_ns()
  time: Refactor accumulation of nsecs to secs
  time: Condense timekeeper.xtime into xtime_sec
  time: Explicitly use u32 instead of int for shift values
  time: Whitespace cleanups per Ingo%27s requests
  nohz: Move next idle expiry time record into idle logic area
  nohz: Move ts->idle_calls incrementation into strict idle logic
  nohz: Rename ts->idle_tick to ts->last_tick
  nohz: Make nohz API agnostic against idle ticks cputime accounting
  nohz: Separate idle sleeping time accounting from nohz logic
  timers: Improve get_next_timer_interrupt()
  timers: Add accounting of non deferrable timers
  timers: Consolidate base->next_timer update
  timers: Create detach_if_pending() and use it
This commit is contained in:
Linus Torvalds 2012-07-22 11:35:46 -07:00
parent 55acdddbac eec19d1a0d
commit 3992c03212
5 changed files with 436 additions and 365 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
include/linux/tick.h
View File

@ -31,10 +31,10 @@ enum tick_nohz_mode {
* struct tick_sched - sched tick emulation and no idle tick control/stats
* @sched_timer: hrtimer to schedule the periodic tick in high
* resolution mode
* @idle_tick: Store the last idle tick expiry time when the tick
* timer is modified for idle sleeps. This is necessary
* @last_tick: Store the last tick expiry time when the tick
* timer is modified for nohz sleeps. This is necessary
* to resume the tick timer operation in the timeline
* when the CPU returns from idle
* when the CPU returns from nohz sleep.
* @tick_stopped: Indicator that the idle tick has been stopped
* @idle_jiffies: jiffies at the entry to idle for idle time accounting
* @idle_calls: Total number of idle calls
@ -51,7 +51,7 @@ struct tick_sched {
struct hrtimer sched_timer;
unsigned long check_clocks;
enum tick_nohz_mode nohz_mode;
ktime_t idle_tick;
ktime_t last_tick;
int inidle;
int tick_stopped;
unsigned long idle_jiffies;

192
kernel/time/tick-sched.c
View File

@ -271,50 +271,15 @@ u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time)
}
EXPORT_SYMBOL_GPL(get_cpu_iowait_time_us);
static void tick_nohz_stop_sched_tick(struct tick_sched *ts)
static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
ktime_t now, int cpu)
{
unsigned long seq, last_jiffies, next_jiffies, delta_jiffies;
ktime_t last_update, expires, ret = { .tv64 = 0 };
unsigned long rcu_delta_jiffies;
ktime_t last_update, expires, now;
struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
u64 time_delta;
int cpu;
cpu = smp_processor_id();
ts = &per_cpu(tick_cpu_sched, cpu);
now = tick_nohz_start_idle(cpu, ts);
/*
* If this cpu is offline and it is the one which updates
* jiffies, then give up the assignment and let it be taken by
* the cpu which runs the tick timer next. If we don't drop
* this here the jiffies might be stale and do_timer() never
* invoked.
*/
if (unlikely(!cpu_online(cpu))) {
if (cpu == tick_do_timer_cpu)
tick_do_timer_cpu = TICK_DO_TIMER_NONE;
}
if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE))
return;
if (need_resched())
return;
if (unlikely(local_softirq_pending() && cpu_online(cpu))) {
static int ratelimit;
if (ratelimit < 10) {
printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n",
(unsigned int) local_softirq_pending());
ratelimit++;
}
return;
}
ts->idle_calls++;
/* Read jiffies and the time when jiffies were updated last */
do {
seq = read_seqbegin(&xtime_lock);
@ -397,6 +362,8 @@ static void tick_nohz_stop_sched_tick(struct tick_sched *ts)
if (ts->tick_stopped && ktime_equal(expires, dev->next_event))
goto out;
ret = expires;
/*
* nohz_stop_sched_tick can be called several times before
* the nohz_restart_sched_tick is called. This happens when
@ -408,16 +375,10 @@ static void tick_nohz_stop_sched_tick(struct tick_sched *ts)
select_nohz_load_balancer(1);
calc_load_enter_idle();
ts->idle_tick = hrtimer_get_expires(&ts->sched_timer);
ts->last_tick = hrtimer_get_expires(&ts->sched_timer);
ts->tick_stopped = 1;
ts->idle_jiffies = last_jiffies;
}
ts->idle_sleeps++;
/* Mark expires */
ts->idle_expires = expires;
/*
* If the expiration time == KTIME_MAX, then
* in this case we simply stop the tick timer.
@ -448,6 +409,65 @@ static void tick_nohz_stop_sched_tick(struct tick_sched *ts)
ts->next_jiffies = next_jiffies;
ts->last_jiffies = last_jiffies;
ts->sleep_length = ktime_sub(dev->next_event, now);
return ret;
}
static bool can_stop_idle_tick(int cpu, struct tick_sched *ts)
{
/*
* If this cpu is offline and it is the one which updates
* jiffies, then give up the assignment and let it be taken by
* the cpu which runs the tick timer next. If we don't drop
* this here the jiffies might be stale and do_timer() never
* invoked.
*/
if (unlikely(!cpu_online(cpu))) {
if (cpu == tick_do_timer_cpu)
tick_do_timer_cpu = TICK_DO_TIMER_NONE;
}
if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE))
return false;
if (need_resched())
return false;
if (unlikely(local_softirq_pending() && cpu_online(cpu))) {
static int ratelimit;
if (ratelimit < 10) {
printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n",
(unsigned int) local_softirq_pending());
ratelimit++;
}
return false;
}
return true;
}
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);
if (can_stop_idle_tick(cpu, ts)) {
int was_stopped = ts->tick_stopped;
ts->idle_calls++;
expires = tick_nohz_stop_sched_tick(ts, now, cpu);
if (expires.tv64 > 0LL) {
ts->idle_sleeps++;
ts->idle_expires = expires;
}
if (!was_stopped && ts->tick_stopped)
ts->idle_jiffies = ts->last_jiffies;
}
}
/**
@ -485,7 +505,7 @@ void tick_nohz_idle_enter(void)
* update of the idle time accounting in tick_nohz_start_idle().
*/
ts->inidle = 1;
tick_nohz_stop_sched_tick(ts);
__tick_nohz_idle_enter(ts);
local_irq_enable();
}
@ -505,7 +525,7 @@ void tick_nohz_irq_exit(void)
if (!ts->inidle)
return;
tick_nohz_stop_sched_tick(ts);
__tick_nohz_idle_enter(ts);
}
/**
@ -523,7 +543,7 @@ ktime_t tick_nohz_get_sleep_length(void)
static void tick_nohz_restart(struct tick_sched *ts, ktime_t now)
{
hrtimer_cancel(&ts->sched_timer);
hrtimer_set_expires(&ts->sched_timer, ts->idle_tick);
hrtimer_set_expires(&ts->sched_timer, ts->last_tick);
while (1) {
/* Forward the time to expire in the future */
@ -546,6 +566,41 @@ static void tick_nohz_restart(struct tick_sched *ts, ktime_t now)
}
}
static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now)
{
/* Update jiffies first */
select_nohz_load_balancer(0);
tick_do_update_jiffies64(now);
update_cpu_load_nohz();
touch_softlockup_watchdog();
/*
* Cancel the scheduled timer and restore the tick
*/
ts->tick_stopped = 0;
ts->idle_exittime = now;
tick_nohz_restart(ts, now);
}
static void tick_nohz_account_idle_ticks(struct tick_sched *ts)
{
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
unsigned long ticks;
/*
* We stopped the tick in idle. Update process times would miss the
* time we slept as update_process_times does only a 1 tick
* accounting. Enforce that this is accounted to idle !
*/
ticks = jiffies - ts->idle_jiffies;
/*
* We might be one off. Do not randomly account a huge number of ticks!
*/
if (ticks && ticks < LONG_MAX)
account_idle_ticks(ticks);
#endif
}
/**
* tick_nohz_idle_exit - restart the idle tick from the idle task
*
@ -557,9 +612,6 @@ void tick_nohz_idle_exit(void)
{
int cpu = smp_processor_id();
struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
unsigned long ticks;
#endif
ktime_t now;
local_irq_disable();
@ -574,40 +626,11 @@ void tick_nohz_idle_exit(void)
if (ts->idle_active)
tick_nohz_stop_idle(cpu, now);
if (!ts->tick_stopped) {
local_irq_enable();
return;
if (ts->tick_stopped) {
tick_nohz_restart_sched_tick(ts, now);
tick_nohz_account_idle_ticks(ts);
}
/* Update jiffies first */
select_nohz_load_balancer(0);
tick_do_update_jiffies64(now);
update_cpu_load_nohz();
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
/*
* We stopped the tick in idle. Update process times would miss the
* time we slept as update_process_times does only a 1 tick
* accounting. Enforce that this is accounted to idle !
*/
ticks = jiffies - ts->idle_jiffies;
/*
* We might be one off. Do not randomly account a huge number of ticks!
*/
if (ticks && ticks < LONG_MAX)
account_idle_ticks(ticks);
#endif
calc_load_exit_idle();
touch_softlockup_watchdog();
/*
* Cancel the scheduled timer and restore the tick
*/
ts->tick_stopped = 0;
ts->idle_exittime = now;
tick_nohz_restart(ts, now);
local_irq_enable();
}
@ -811,7 +834,8 @@ static enum hrtimer_restart tick_sched_timer(struct hrtimer *timer)
*/
if (ts->tick_stopped) {
touch_softlockup_watchdog();
ts->idle_jiffies++;
if (idle_cpu(cpu))
ts->idle_jiffies++;
}
update_process_times(user_mode(regs));
profile_tick(CPU_PROFILING);

487
kernel/time/timekeeping.c
View File

@ -24,32 +24,32 @@
/* Structure holding internal timekeeping values. */
struct timekeeper {
/* Current clocksource used for timekeeping. */
struct clocksource *clock;
struct clocksource *clock;
/* NTP adjusted clock multiplier */
u32 mult;
u32 mult;
/* The shift value of the current clocksource. */
int shift;
u32 shift;
/* Number of clock cycles in one NTP interval. */
cycle_t cycle_interval;
cycle_t cycle_interval;
/* Number of clock shifted nano seconds in one NTP interval. */
u64 xtime_interval;
u64 xtime_interval;
/* shifted nano seconds left over when rounding cycle_interval */
s64 xtime_remainder;
s64 xtime_remainder;
/* Raw nano seconds accumulated per NTP interval. */
u32 raw_interval;
u32 raw_interval;
/* Current CLOCK_REALTIME time in seconds */
u64 xtime_sec;
/* Clock shifted nano seconds */
u64 xtime_nsec;
/* Clock shifted nano seconds remainder not stored in xtime.tv_nsec. */
u64 xtime_nsec;
/* Difference between accumulated time and NTP time in ntp
* shifted nano seconds. */
s64 ntp_error;
s64 ntp_error;
/* Shift conversion between clock shifted nano seconds and
* ntp shifted nano seconds. */
int ntp_error_shift;
u32 ntp_error_shift;
/* The current time */
struct timespec xtime;
/*
* wall_to_monotonic is what we need to add to xtime (or xtime corrected
* for sub jiffie times) to get to monotonic time. Monotonic is pegged
@ -64,20 +64,17 @@ struct timekeeper {
* - wall_to_monotonic is no longer the boot time, getboottime must be
* used instead.
*/
struct timespec wall_to_monotonic;
struct timespec wall_to_monotonic;
/* time spent in suspend */
struct timespec total_sleep_time;
struct timespec total_sleep_time;
/* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
struct timespec raw_time;
struct timespec raw_time;
/* Offset clock monotonic -> clock realtime */
ktime_t offs_real;
ktime_t offs_real;
/* Offset clock monotonic -> clock boottime */
ktime_t offs_boot;
ktime_t offs_boot;
/* Seqlock for all timekeeper values */
seqlock_t lock;
seqlock_t lock;
};
static struct timekeeper timekeeper;
@ -88,11 +85,37 @@ static struct timekeeper timekeeper;
*/
__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
/* flag for if timekeeping is suspended */
int __read_mostly timekeeping_suspended;
static inline void tk_normalize_xtime(struct timekeeper *tk)
{
while (tk->xtime_nsec >= ((u64)NSEC_PER_SEC << tk->shift)) {
tk->xtime_nsec -= (u64)NSEC_PER_SEC << tk->shift;
tk->xtime_sec++;
}
}
static struct timespec tk_xtime(struct timekeeper *tk)
{
struct timespec ts;
ts.tv_sec = tk->xtime_sec;
ts.tv_nsec = (long)(tk->xtime_nsec >> tk->shift);
return ts;
}
static void tk_set_xtime(struct timekeeper *tk, const struct timespec *ts)
{
tk->xtime_sec = ts->tv_sec;
tk->xtime_nsec = ts->tv_nsec << tk->shift;
}
static void tk_xtime_add(struct timekeeper *tk, const struct timespec *ts)
{
tk->xtime_sec += ts->tv_sec;
tk->xtime_nsec += ts->tv_nsec << tk->shift;
}
/**
* timekeeper_setup_internals - Set up internals to use clocksource clock.
@ -104,12 +127,14 @@ int __read_mostly timekeeping_suspended;
*
* Unless you're the timekeeping code, you should not be using this!
*/
static void timekeeper_setup_internals(struct clocksource *clock)
static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock)
{
cycle_t interval;
u64 tmp, ntpinterval;
struct clocksource *old_clock;
timekeeper.clock = clock;
old_clock = tk->clock;
tk->clock = clock;
clock->cycle_last = clock->read(clock);
/* Do the ns -> cycle conversion first, using original mult */
@ -122,80 +147,96 @@ static void timekeeper_setup_internals(struct clocksource *clock)
tmp = 1;
interval = (cycle_t) tmp;
timekeeper.cycle_interval = interval;
tk->cycle_interval = interval;
/* Go back from cycles -> shifted ns */
timekeeper.xtime_interval = (u64) interval * clock->mult;
timekeeper.xtime_remainder = ntpinterval - timekeeper.xtime_interval;
timekeeper.raw_interval =
tk->xtime_interval = (u64) interval * clock->mult;
tk->xtime_remainder = ntpinterval - tk->xtime_interval;
tk->raw_interval =
((u64) interval * clock->mult) >> clock->shift;
timekeeper.xtime_nsec = 0;
timekeeper.shift = clock->shift;
/* if changing clocks, convert xtime_nsec shift units */
if (old_clock) {
int shift_change = clock->shift - old_clock->shift;
if (shift_change < 0)
tk->xtime_nsec >>= -shift_change;
else
tk->xtime_nsec <<= shift_change;
}
tk->shift = clock->shift;
timekeeper.ntp_error = 0;
timekeeper.ntp_error_shift = NTP_SCALE_SHIFT - clock->shift;
tk->ntp_error = 0;
tk->ntp_error_shift = NTP_SCALE_SHIFT - clock->shift;
/*
* The timekeeper keeps its own mult values for the currently
* active clocksource. These value will be adjusted via NTP
* to counteract clock drifting.
*/
timekeeper.mult = clock->mult;
tk->mult = clock->mult;
}
/* Timekeeper helper functions. */
static inline s64 timekeeping_get_ns(void)
static inline s64 timekeeping_get_ns(struct timekeeper *tk)
{
cycle_t cycle_now, cycle_delta;
struct clocksource *clock;
s64 nsec;
/* read clocksource: */
clock = timekeeper.clock;
clock = tk->clock;
cycle_now = clock->read(clock);
/* calculate the delta since the last update_wall_time: */
cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
/* return delta convert to nanoseconds using ntp adjusted mult. */
return clocksource_cyc2ns(cycle_delta, timekeeper.mult,
timekeeper.shift);
nsec = cycle_delta * tk->mult + tk->xtime_nsec;
nsec >>= tk->shift;
/* If arch requires, add in gettimeoffset() */
return nsec + arch_gettimeoffset();
}
static inline s64 timekeeping_get_ns_raw(void)
static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
{
cycle_t cycle_now, cycle_delta;
struct clocksource *clock;
s64 nsec;
/* read clocksource: */
clock = timekeeper.clock;
clock = tk->clock;
cycle_now = clock->read(clock);
/* calculate the delta since the last update_wall_time: */
cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
/* return delta convert to nanoseconds. */
return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
/* convert delta to nanoseconds. */
nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
/* If arch requires, add in gettimeoffset() */
return nsec + arch_gettimeoffset();
}
static void update_rt_offset(void)
static void update_rt_offset(struct timekeeper *tk)
{
struct timespec tmp, *wtm = &timekeeper.wall_to_monotonic;
struct timespec tmp, *wtm = &tk->wall_to_monotonic;
set_normalized_timespec(&tmp, -wtm->tv_sec, -wtm->tv_nsec);
timekeeper.offs_real = timespec_to_ktime(tmp);
tk->offs_real = timespec_to_ktime(tmp);
}
/* must hold write on timekeeper.lock */
static void timekeeping_update(bool clearntp)
static void timekeeping_update(struct timekeeper *tk, bool clearntp)
{
struct timespec xt;
if (clearntp) {
timekeeper.ntp_error = 0;
tk->ntp_error = 0;
ntp_clear();
}
update_rt_offset();
update_vsyscall(&timekeeper.xtime, &timekeeper.wall_to_monotonic,
timekeeper.clock, timekeeper.mult);
update_rt_offset(tk);
xt = tk_xtime(tk);
update_vsyscall(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult);
}
@ -206,27 +247,26 @@ static void timekeeping_update(bool clearntp)
* update_wall_time(). This is useful before significant clock changes,
* as it avoids having to deal with this time offset explicitly.
*/
static void timekeeping_forward_now(void)
static void timekeeping_forward_now(struct timekeeper *tk)
{
cycle_t cycle_now, cycle_delta;
struct clocksource *clock;
s64 nsec;
clock = timekeeper.clock;
clock = tk->clock;
cycle_now = clock->read(clock);
cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
clock->cycle_last = cycle_now;
nsec = clocksource_cyc2ns(cycle_delta, timekeeper.mult,
timekeeper.shift);
tk->xtime_nsec += cycle_delta * tk->mult;
/* If arch requires, add in gettimeoffset() */
nsec += arch_gettimeoffset();
tk->xtime_nsec += arch_gettimeoffset() << tk->shift;
timespec_add_ns(&timekeeper.xtime, nsec);
tk_normalize_xtime(tk);
nsec = clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
timespec_add_ns(&timekeeper.raw_time, nsec);
timespec_add_ns(&tk->raw_time, nsec);
}
/**
@ -238,18 +278,15 @@ static void timekeeping_forward_now(void)
void getnstimeofday(struct timespec *ts)
{
unsigned long seq;
s64 nsecs;
s64 nsecs = 0;
WARN_ON(timekeeping_suspended);
do {
seq = read_seqbegin(&timekeeper.lock);
*ts = timekeeper.xtime;
nsecs = timekeeping_get_ns();
/* If arch requires, add in gettimeoffset() */
nsecs += arch_gettimeoffset();
ts->tv_sec = timekeeper.xtime_sec;
ts->tv_nsec = timekeeping_get_ns(&timekeeper);
} while (read_seqretry(&timekeeper.lock, seq));
@ -266,13 +303,10 @@ ktime_t ktime_get(void)
do {
seq = read_seqbegin(&timekeeper.lock);
secs = timekeeper.xtime.tv_sec +
secs = timekeeper.xtime_sec +
timekeeper.wall_to_monotonic.tv_sec;
nsecs = timekeeper.xtime.tv_nsec +
nsecs = timekeeping_get_ns(&timekeeper) +
timekeeper.wall_to_monotonic.tv_nsec;
nsecs += timekeeping_get_ns();
/* If arch requires, add in gettimeoffset() */
nsecs += arch_gettimeoffset();
} while (read_seqretry(&timekeeper.lock, seq));
/*
@ -295,22 +329,19 @@ void ktime_get_ts(struct timespec *ts)
{
struct timespec tomono;
unsigned int seq;
s64 nsecs;
WARN_ON(timekeeping_suspended);
do {
seq = read_seqbegin(&timekeeper.lock);
*ts = timekeeper.xtime;
ts->tv_sec = timekeeper.xtime_sec;
ts->tv_nsec = timekeeping_get_ns(&timekeeper);
tomono = timekeeper.wall_to_monotonic;
nsecs = timekeeping_get_ns();
/* If arch requires, add in gettimeoffset() */
nsecs += arch_gettimeoffset();
} while (read_seqretry(&timekeeper.lock, seq));
set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
ts->tv_nsec + tomono.tv_nsec + nsecs);
ts->tv_nsec + tomono.tv_nsec);
}
EXPORT_SYMBOL_GPL(ktime_get_ts);
@ -333,20 +364,14 @@ void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
WARN_ON_ONCE(timekeeping_suspended);
do {
u32 arch_offset;
seq = read_seqbegin(&timekeeper.lock);
*ts_raw = timekeeper.raw_time;
*ts_real = timekeeper.xtime;
ts_real->tv_sec = timekeeper.xtime_sec;
ts_real->tv_nsec = 0;
nsecs_raw = timekeeping_get_ns_raw();
nsecs_real = timekeeping_get_ns();
/* If arch requires, add in gettimeoffset() */
arch_offset = arch_gettimeoffset();
nsecs_raw += arch_offset;
nsecs_real += arch_offset;
nsecs_raw = timekeeping_get_ns_raw(&timekeeper);
nsecs_real = timekeeping_get_ns(&timekeeper);
} while (read_seqretry(&timekeeper.lock, seq));
@ -381,7 +406,7 @@ EXPORT_SYMBOL(do_gettimeofday);
*/
int do_settimeofday(const struct timespec *tv)
{
struct timespec ts_delta;
struct timespec ts_delta, xt;
unsigned long flags;
if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
@ -389,15 +414,18 @@ int do_settimeofday(const struct timespec *tv)
write_seqlock_irqsave(&timekeeper.lock, flags);
timekeeping_forward_now();
timekeeping_forward_now(&timekeeper);
xt = tk_xtime(&timekeeper);
ts_delta.tv_sec = tv->tv_sec - xt.tv_sec;
ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec;
ts_delta.tv_sec = tv->tv_sec - timekeeper.xtime.tv_sec;
ts_delta.tv_nsec = tv->tv_nsec - timekeeper.xtime.tv_nsec;
timekeeper.wall_to_monotonic =
timespec_sub(timekeeper.wall_to_monotonic, ts_delta);
timekeeper.xtime = *tv;
timekeeping_update(true);
tk_set_xtime(&timekeeper, tv);
timekeeping_update(&timekeeper, true);
write_sequnlock_irqrestore(&timekeeper.lock, flags);
@ -424,13 +452,14 @@ int timekeeping_inject_offset(struct timespec *ts)
write_seqlock_irqsave(&timekeeper.lock, flags);
timekeeping_forward_now();
timekeeping_forward_now(&timekeeper);
timekeeper.xtime = timespec_add(timekeeper.xtime, *ts);
tk_xtime_add(&timekeeper, ts);
timekeeper.wall_to_monotonic =
timespec_sub(timekeeper.wall_to_monotonic, *ts);
timekeeping_update(true);
timekeeping_update(&timekeeper, true);
write_sequnlock_irqrestore(&timekeeper.lock, flags);
@ -455,14 +484,14 @@ static int change_clocksource(void *data)
write_seqlock_irqsave(&timekeeper.lock, flags);
timekeeping_forward_now();
timekeeping_forward_now(&timekeeper);
if (!new->enable || new->enable(new) == 0) {
old = timekeeper.clock;
timekeeper_setup_internals(new);
tk_setup_internals(&timekeeper, new);
if (old->disable)
old->disable(old);
}
timekeeping_update(true);
timekeeping_update(&timekeeper, true);
write_sequnlock_irqrestore(&timekeeper.lock, flags);
@ -512,7 +541,7 @@ void getrawmonotonic(struct timespec *ts)
do {
seq = read_seqbegin(&timekeeper.lock);
nsecs = timekeeping_get_ns_raw();
nsecs = timekeeping_get_ns_raw(&timekeeper);
*ts = timekeeper.raw_time;
} while (read_seqretry(&timekeeper.lock, seq));
@ -547,6 +576,7 @@ u64 timekeeping_max_deferment(void)
{
unsigned long seq;
u64 ret;
do {
seq = read_seqbegin(&timekeeper.lock);
@ -607,19 +637,17 @@ void __init timekeeping_init(void)
clock = clocksource_default_clock();
if (clock->enable)
clock->enable(clock);
timekeeper_setup_internals(clock);
tk_setup_internals(&timekeeper, clock);
timekeeper.xtime.tv_sec = now.tv_sec;
timekeeper.xtime.tv_nsec = now.tv_nsec;
tk_set_xtime(&timekeeper, &now);
timekeeper.raw_time.tv_sec = 0;
timekeeper.raw_time.tv_nsec = 0;
if (boot.tv_sec == 0 && boot.tv_nsec == 0) {
boot.tv_sec = timekeeper.xtime.tv_sec;
boot.tv_nsec = timekeeper.xtime.tv_nsec;
}
if (boot.tv_sec == 0 && boot.tv_nsec == 0)
boot = tk_xtime(&timekeeper);
set_normalized_timespec(&timekeeper.wall_to_monotonic,
-boot.tv_sec, -boot.tv_nsec);
update_rt_offset();
update_rt_offset(&timekeeper);
timekeeper.total_sleep_time.tv_sec = 0;
timekeeper.total_sleep_time.tv_nsec = 0;
write_sequnlock_irqrestore(&timekeeper.lock, flags);
@ -641,7 +669,8 @@ static void update_sleep_time(struct timespec t)
* Takes a timespec offset measuring a suspend interval and properly
* adds the sleep offset to the timekeeping variables.
*/
static void __timekeeping_inject_sleeptime(struct timespec *delta)
static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
struct timespec *delta)
{
if (!timespec_valid(delta)) {
printk(KERN_WARNING "__timekeeping_inject_sleeptime: Invalid "
@ -649,10 +678,9 @@ static void __timekeeping_inject_sleeptime(struct timespec *delta)
return;
}
timekeeper.xtime = timespec_add(timekeeper.xtime, *delta);
timekeeper.wall_to_monotonic =
timespec_sub(timekeeper.wall_to_monotonic, *delta);
update_sleep_time(timespec_add(timekeeper.total_sleep_time, *delta));
tk_xtime_add(tk, delta);
tk->wall_to_monotonic = timespec_sub(tk->wall_to_monotonic, *delta);
update_sleep_time(timespec_add(tk->total_sleep_time, *delta));
}
@ -678,11 +706,11 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
write_seqlock_irqsave(&timekeeper.lock, flags);
timekeeping_forward_now();
timekeeping_forward_now(&timekeeper);
__timekeeping_inject_sleeptime(delta);
__timekeeping_inject_sleeptime(&timekeeper, delta);
timekeeping_update(true);
timekeeping_update(&timekeeper, true);
write_sequnlock_irqrestore(&timekeeper.lock, flags);
@ -711,13 +739,13 @@ static void timekeeping_resume(void)
if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
ts = timespec_sub(ts, timekeeping_suspend_time);
__timekeeping_inject_sleeptime(&ts);
__timekeeping_inject_sleeptime(&timekeeper, &ts);
}
/* re-base the last cycle value */
timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);
timekeeper.ntp_error = 0;
timekeeping_suspended = 0;
timekeeping_update(false);
timekeeping_update(&timekeeper, false);
write_sequnlock_irqrestore(&timekeeper.lock, flags);
touch_softlockup_watchdog();
@ -737,7 +765,7 @@ static int timekeeping_suspend(void)
read_persistent_clock(&timekeeping_suspend_time);
write_seqlock_irqsave(&timekeeper.lock, flags);
timekeeping_forward_now();
timekeeping_forward_now(&timekeeper);
timekeeping_suspended = 1;
/*
@ -746,7 +774,7 @@ static int timekeeping_suspend(void)
* try to compensate so the difference in system time
* and persistent_clock time stays close to constant.
*/
delta = timespec_sub(timekeeper.xtime, timekeeping_suspend_time);
delta = timespec_sub(tk_xtime(&timekeeper), timekeeping_suspend_time);
delta_delta = timespec_sub(delta, old_delta);
if (abs(delta_delta.tv_sec) >= 2) {
/*
@ -785,7 +813,8 @@ device_initcall(timekeeping_init_ops);
* If the error is already larger, we look ahead even further
* to compensate for late or lost adjustments.
*/
static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval,
static __always_inline int timekeeping_bigadjust(struct timekeeper *tk,
s64 error, s64 *interval,
s64 *offset)
{
s64 tick_error, i;
@ -801,7 +830,7 @@ static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval,
* here. This is tuned so that an error of about 1 msec is adjusted
* within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks).
*/
error2 = timekeeper.ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ);
error2 = tk->ntp_error >> (NTP_SCALE_SHIFT + 22 - 2 * SHIFT_HZ);
error2 = abs(error2);
for (look_ahead = 0; error2 > 0; look_ahead++)
error2 >>= 2;
@ -810,8 +839,8 @@ static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval,
* Now calculate the error in (1 << look_ahead) ticks, but first
* remove the single look ahead already included in the error.
*/
tick_error = ntp_tick_length() >> (timekeeper.ntp_error_shift + 1);
tick_error -= timekeeper.xtime_interval >> 1;
tick_error = ntp_tick_length() >> (tk->ntp_error_shift + 1);
tick_error -= tk->xtime_interval >> 1;
error = ((error - tick_error) >> look_ahead) + tick_error;
/* Finally calculate the adjustment shift value. */
@ -836,9 +865,9 @@ static __always_inline int timekeeping_bigadjust(s64 error, s64 *interval,
* this is optimized for the most common adjustments of -1,0,1,
* for other values we can do a bit more work.
*/
static void timekeeping_adjust(s64 offset)
static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
{
s64 error, interval = timekeeper.cycle_interval;
s64 error, interval = tk->cycle_interval;
int adj;
/*
@ -854,7 +883,7 @@ static void timekeeping_adjust(s64 offset)
*
* Note: It does not "save" on aggravation when reading the code.
*/
error = timekeeper.ntp_error >> (timekeeper.ntp_error_shift - 1);
error = tk->ntp_error >> (tk->ntp_error_shift - 1);
if (error > interval) {
/*
* We now divide error by 4(via shift), which checks if
@ -876,7 +905,8 @@ static void timekeeping_adjust(s64 offset)
if (likely(error <= interval))
adj = 1;
else
adj = timekeeping_bigadjust(error, &interval, &offset);
adj = timekeeping_bigadjust(tk, error, &interval,
&offset);
} else if (error < -interval) {
/* See comment above, this is just switched for the negative */
error >>= 2;
@ -885,18 +915,17 @@ static void timekeeping_adjust(s64 offset)
interval = -interval;
offset = -offset;
} else
adj = timekeeping_bigadjust(error, &interval, &offset);
} else /* No adjustment needed */
adj = timekeeping_bigadjust(tk, error, &interval,
&offset);
} else
return;
if (unlikely(timekeeper.clock->maxadj &&
(timekeeper.mult + adj >
timekeeper.clock->mult + timekeeper.clock->maxadj))) {
if (unlikely(tk->clock->maxadj &&
(tk->mult + adj > tk->clock->mult + tk->clock->maxadj))) {
printk_once(KERN_WARNING
"Adjusting %s more than 11%% (%ld vs %ld)\n",
timekeeper.clock->name, (long)timekeeper.mult + adj,
(long)timekeeper.clock->mult +
timekeeper.clock->maxadj);
tk->clock->name, (long)tk->mult + adj,
(long)tk->clock->mult + tk->clock->maxadj);
}
/*
* So the following can be confusing.
@ -947,11 +976,60 @@ static void timekeeping_adjust(s64 offset)
*
* XXX - TODO: Doc ntp_error calculation.
*/
timekeeper.mult += adj;
timekeeper.xtime_interval += interval;
timekeeper.xtime_nsec -= offset;
timekeeper.ntp_error -= (interval - offset) <<
timekeeper.ntp_error_shift;
tk->mult += adj;
tk->xtime_interval += interval;
tk->xtime_nsec -= offset;
tk->ntp_error -= (interval - offset) << tk->ntp_error_shift;
/*
* It may be possible that when we entered this function, xtime_nsec
* was very small. Further, if we're slightly speeding the clocksource
* in the code above, its possible the required corrective factor to
* xtime_nsec could cause it to underflow.
*
* Now, since we already accumulated the second, cannot simply roll
* the accumulated second back, since the NTP subsystem has been
* notified via second_overflow. So instead we push xtime_nsec forward
* by the amount we underflowed, and add that amount into the error.
*
* We'll correct this error next time through this function, when
* xtime_nsec is not as small.
*/
if (unlikely((s64)tk->xtime_nsec < 0)) {
s64 neg = -(s64)tk->xtime_nsec;
tk->xtime_nsec = 0;
tk->ntp_error += neg << tk->ntp_error_shift;
}
}
/**
* accumulate_nsecs_to_secs - Accumulates nsecs into secs
*
* Helper function that accumulates a the nsecs greater then a second
* from the xtime_nsec field to the xtime_secs field.
* It also calls into the NTP code to handle leapsecond processing.
*
*/
static inline void accumulate_nsecs_to_secs(struct timekeeper *tk)
{
u64 nsecps = (u64)NSEC_PER_SEC << tk->shift;
while (tk->xtime_nsec >= nsecps) {
int leap;
tk->xtime_nsec -= nsecps;
tk->xtime_sec++;
/* Figure out if its a leap sec and apply if needed */
leap = second_overflow(tk->xtime_sec);
tk->xtime_sec += leap;
tk->wall_to_monotonic.tv_sec -= leap;
if (leap)
clock_was_set_delayed();
}
}
@ -964,46 +1042,36 @@ static void timekeeping_adjust(s64 offset)
*
* Returns the unconsumed cycles.
*/
static cycle_t logarithmic_accumulation(cycle_t offset, int shift)
static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
u32 shift)
{
u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift;
u64 raw_nsecs;
/* If the offset is smaller than a shifted interval, do nothing */
if (offset < timekeeper.cycle_interval<<shift)
/* If the offset is smaller then a shifted interval, do nothing */
if (offset < tk->cycle_interval<<shift)
return offset;
/* Accumulate one shifted interval */
offset -= timekeeper.cycle_interval << shift;
timekeeper.clock->cycle_last += timekeeper.cycle_interval << shift;
offset -= tk->cycle_interval << shift;
tk->clock->cycle_last += tk->cycle_interval << shift;
timekeeper.xtime_nsec += timekeeper.xtime_interval << shift;
while (timekeeper.xtime_nsec >= nsecps) {
int leap;
timekeeper.xtime_nsec -= nsecps;
timekeeper.xtime.tv_sec++;
leap = second_overflow(timekeeper.xtime.tv_sec);
timekeeper.xtime.tv_sec += leap;
timekeeper.wall_to_monotonic.tv_sec -= leap;
if (leap)
clock_was_set_delayed();
}
tk->xtime_nsec += tk->xtime_interval << shift;
accumulate_nsecs_to_secs(tk);
/* Accumulate raw time */
raw_nsecs = timekeeper.raw_interval << shift;
raw_nsecs += timekeeper.raw_time.tv_nsec;
raw_nsecs = tk->raw_interval << shift;
raw_nsecs += tk->raw_time.tv_nsec;
if (raw_nsecs >= NSEC_PER_SEC) {
u64 raw_secs = raw_nsecs;
raw_nsecs = do_div(raw_secs, NSEC_PER_SEC);
timekeeper.raw_time.tv_sec += raw_secs;
tk->raw_time.tv_sec += raw_secs;
}
timekeeper.raw_time.tv_nsec = raw_nsecs;
tk->raw_time.tv_nsec = raw_nsecs;
/* Accumulate error between NTP and clock interval */
timekeeper.ntp_error += ntp_tick_length() << shift;
timekeeper.ntp_error -=
(timekeeper.xtime_interval + timekeeper.xtime_remainder) <<
(timekeeper.ntp_error_shift + shift);
tk->ntp_error += ntp_tick_length() << shift;
tk->ntp_error -= (tk->xtime_interval + tk->xtime_remainder) <<
(tk->ntp_error_shift + shift);
return offset;
}
@ -1019,6 +1087,7 @@ static void update_wall_time(void)
cycle_t offset;
int shift = 0, maxshift;
unsigned long flags;
s64 remainder;
write_seqlock_irqsave(&timekeeper.lock, flags);
@ -1033,8 +1102,6 @@ static void update_wall_time(void)
#else
offset = (clock->read(clock) - clock->cycle_last) & clock->mask;
#endif
timekeeper.xtime_nsec = (s64)timekeeper.xtime.tv_nsec <<
timekeeper.shift;
/*
* With NO_HZ we may have to accumulate many cycle_intervals
@ -1050,64 +1117,36 @@ static void update_wall_time(void)
maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1;
shift = min(shift, maxshift);
while (offset >= timekeeper.cycle_interval) {
offset = logarithmic_accumulation(offset, shift);
offset = logarithmic_accumulation(&timekeeper, offset, shift);
if(offset < timekeeper.cycle_interval<<shift)
shift--;
}
/* correct the clock when NTP error is too big */
timekeeping_adjust(offset);
/*
* Since in the loop above, we accumulate any amount of time
* in xtime_nsec over a second into xtime.tv_sec, its possible for
* xtime_nsec to be fairly small after the loop. Further, if we're
* slightly speeding the clocksource up in timekeeping_adjust(),
* its possible the required corrective factor to xtime_nsec could
* cause it to underflow.
*
* Now, we cannot simply roll the accumulated second back, since
* the NTP subsystem has been notified via second_overflow. So
* instead we push xtime_nsec forward by the amount we underflowed,
* and add that amount into the error.
*
* We'll correct this error next time through this function, when
* xtime_nsec is not as small.
*/
if (unlikely((s64)timekeeper.xtime_nsec < 0)) {
s64 neg = -(s64)timekeeper.xtime_nsec;
timekeeper.xtime_nsec = 0;
timekeeper.ntp_error += neg << timekeeper.ntp_error_shift;
}
timekeeping_adjust(&timekeeper, offset);
/*
* Store full nanoseconds into xtime after rounding it up and
* add the remainder to the error difference.
*/
timekeeper.xtime.tv_nsec = ((s64)timekeeper.xtime_nsec >>
timekeeper.shift) + 1;
timekeeper.xtime_nsec -= (s64)timekeeper.xtime.tv_nsec <<
timekeeper.shift;
timekeeper.ntp_error += timekeeper.xtime_nsec <<
timekeeper.ntp_error_shift;
* Store only full nanoseconds into xtime_nsec after rounding
* it up and add the remainder to the error difference.
* XXX - This is necessary to avoid small 1ns inconsistnecies caused
* by truncating the remainder in vsyscalls. However, it causes
* additional work to be done in timekeeping_adjust(). Once
* the vsyscall implementations are converted to use xtime_nsec
* (shifted nanoseconds), this can be killed.
*/
remainder = timekeeper.xtime_nsec & ((1 << timekeeper.shift) - 1);
timekeeper.xtime_nsec -= remainder;
timekeeper.xtime_nsec += 1 << timekeeper.shift;
timekeeper.ntp_error += remainder << timekeeper.ntp_error_shift;
/*
* Finally, make sure that after the rounding
* xtime.tv_nsec isn't larger than NSEC_PER_SEC
* xtime_nsec isn't larger than NSEC_PER_SEC
*/
if (unlikely(timekeeper.xtime.tv_nsec >= NSEC_PER_SEC)) {
int leap;
timekeeper.xtime.tv_nsec -= NSEC_PER_SEC;
timekeeper.xtime.tv_sec++;
leap = second_overflow(timekeeper.xtime.tv_sec);
timekeeper.xtime.tv_sec += leap;
timekeeper.wall_to_monotonic.tv_sec -= leap;
if (leap)
clock_was_set_delayed();
}
accumulate_nsecs_to_secs(&timekeeper);
timekeeping_update(false);
timekeeping_update(&timekeeper, false);
out:
write_sequnlock_irqrestore(&timekeeper.lock, flags);
@ -1152,21 +1191,20 @@ void get_monotonic_boottime(struct timespec *ts)
{
struct timespec tomono, sleep;
unsigned int seq;
s64 nsecs;
WARN_ON(timekeeping_suspended);
do {
seq = read_seqbegin(&timekeeper.lock);
*ts = timekeeper.xtime;
ts->tv_sec = timekeeper.xtime_sec;
ts->tv_nsec = timekeeping_get_ns(&timekeeper);
tomono = timekeeper.wall_to_monotonic;
sleep = timekeeper.total_sleep_time;
nsecs = timekeeping_get_ns();
} while (read_seqretry(&timekeeper.lock, seq));
set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec + sleep.tv_sec,
ts->tv_nsec + tomono.tv_nsec + sleep.tv_nsec + nsecs);
ts->tv_nsec + tomono.tv_nsec + sleep.tv_nsec);
}
EXPORT_SYMBOL_GPL(get_monotonic_boottime);
@ -1199,13 +1237,13 @@ EXPORT_SYMBOL_GPL(monotonic_to_bootbased);
unsigned long get_seconds(void)
{
return timekeeper.xtime.tv_sec;
return timekeeper.xtime_sec;
}
EXPORT_SYMBOL(get_seconds);
struct timespec __current_kernel_time(void)
{
return timekeeper.xtime;
return tk_xtime(&timekeeper);
}
struct timespec current_kernel_time(void)
@ -1216,7 +1254,7 @@ struct timespec current_kernel_time(void)
do {
seq = read_seqbegin(&timekeeper.lock);
now = timekeeper.xtime;
now = tk_xtime(&timekeeper);
} while (read_seqretry(&timekeeper.lock, seq));
return now;
@ -1231,7 +1269,7 @@ struct timespec get_monotonic_coarse(void)
do {
seq = read_seqbegin(&timekeeper.lock);
now = timekeeper.xtime;
now = tk_xtime(&timekeeper);
mono = timekeeper.wall_to_monotonic;
} while (read_seqretry(&timekeeper.lock, seq));
@ -1266,7 +1304,7 @@ void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
do {
seq = read_seqbegin(&timekeeper.lock);
*xtim = timekeeper.xtime;
*xtim = tk_xtime(&timekeeper);
*wtom = timekeeper.wall_to_monotonic;
*sleep = timekeeper.total_sleep_time;
} while (read_seqretry(&timekeeper.lock, seq));
@ -1290,11 +1328,8 @@ ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot)
do {
seq = read_seqbegin(&timekeeper.lock);
secs = timekeeper.xtime.tv_sec;
nsecs = timekeeper.xtime.tv_nsec;
nsecs += timekeeping_get_ns();
/* If arch requires, add in gettimeoffset() */
nsecs += arch_gettimeoffset();
secs = timekeeper.xtime_sec;
nsecs = timekeeping_get_ns(&timekeeper);
*offs_real = timekeeper.offs_real;
*offs_boot = timekeeper.offs_boot;

4
kernel/time/timer_list.c
View File

@ -167,7 +167,7 @@ static void print_cpu(struct seq_file *m, int cpu, u64 now)
{
struct tick_sched *ts = tick_get_tick_sched(cpu);
P(nohz_mode);
P_ns(idle_tick);
P_ns(last_tick);
P(tick_stopped);
P(idle_jiffies);
P(idle_calls);
@ -259,7 +259,7 @@ static int timer_list_show(struct seq_file *m, void *v)
u64 now = ktime_to_ns(ktime_get());
int cpu;
SEQ_printf(m, "Timer List Version: v0.6\n");
SEQ_printf(m, "Timer List Version: v0.7\n");
SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);

110
kernel/timer.c
View File

@ -77,6 +77,7 @@ struct tvec_base {
struct timer_list *running_timer;
unsigned long timer_jiffies;
unsigned long next_timer;
unsigned long active_timers;
struct tvec_root tv1;
struct tvec tv2;
struct tvec tv3;
@ -330,7 +331,8 @@ void set_timer_slack(struct timer_list *timer, int slack_hz)
}
EXPORT_SYMBOL_GPL(set_timer_slack);
static void internal_add_timer(struct tvec_base *base, struct timer_list *timer)
static void
__internal_add_timer(struct tvec_base *base, struct timer_list *timer)
{
unsigned long expires = timer->expires;
unsigned long idx = expires - base->timer_jiffies;
@ -372,6 +374,19 @@ static void internal_add_timer(struct tvec_base *base, struct timer_list *timer)
list_add_tail(&timer->entry, vec);
}
static void internal_add_timer(struct tvec_base *base, struct timer_list *timer)
{
__internal_add_timer(base, timer);
/*
* Update base->active_timers and base->next_timer
*/
if (!tbase_get_deferrable(timer->base)) {
if (time_before(timer->expires, base->next_timer))
base->next_timer = timer->expires;
base->active_timers++;
}
}
#ifdef CONFIG_TIMER_STATS
void __timer_stats_timer_set_start_info(struct timer_list *timer, void *addr)
{
@ -654,8 +669,7 @@ void init_timer_deferrable_key(struct timer_list *timer,
}
EXPORT_SYMBOL(init_timer_deferrable_key);
static inline void detach_timer(struct timer_list *timer,
int clear_pending)
static inline void detach_timer(struct timer_list *timer, bool clear_pending)
{
struct list_head *entry = &timer->entry;
@ -667,6 +681,29 @@ static inline void detach_timer(struct timer_list *timer,
entry->prev = LIST_POISON2;
}
static inline void
detach_expired_timer(struct timer_list *timer, struct tvec_base *base)
{
detach_timer(timer, true);
if (!tbase_get_deferrable(timer->base))
timer->base->active_timers--;
}
static int detach_if_pending(struct timer_list *timer, struct tvec_base *base,
bool clear_pending)
{
if (!timer_pending(timer))
return 0;
detach_timer(timer, clear_pending);
if (!tbase_get_deferrable(timer->base)) {
timer->base->active_timers--;
if (timer->expires == base->next_timer)
base->next_timer = base->timer_jiffies;
}
return 1;
}
/*
* We are using hashed locking: holding per_cpu(tvec_bases).lock
* means that all timers which are tied to this base via timer->base are
@ -712,16 +749,9 @@ __mod_timer(struct timer_list *timer, unsigned long expires,
base = lock_timer_base(timer, &flags);
if (timer_pending(timer)) {
detach_timer(timer, 0);
if (timer->expires == base->next_timer &&
!tbase_get_deferrable(timer->base))
base->next_timer = base->timer_jiffies;
ret = 1;
} else {
if (pending_only)
goto out_unlock;
}
ret = detach_if_pending(timer, base, false);
if (!ret && pending_only)
goto out_unlock;
debug_activate(timer, expires);
@ -752,9 +782,6 @@ __mod_timer(struct timer_list *timer, unsigned long expires,
}
timer->expires = expires;
if (time_before(timer->expires, base->next_timer) &&
!tbase_get_deferrable(timer->base))
base->next_timer = timer->expires;
internal_add_timer(base, timer);
out_unlock:
@ -920,9 +947,6 @@ void add_timer_on(struct timer_list *timer, int cpu)
spin_lock_irqsave(&base->lock, flags);
timer_set_base(timer, base);
debug_activate(timer, timer->expires);
if (time_before(timer->expires, base->next_timer) &&
!tbase_get_deferrable(timer->base))
base->next_timer = timer->expires;
internal_add_timer(base, timer);
/*
* Check whether the other CPU is idle and needs to be
@ -959,13 +983,7 @@ int del_timer(struct timer_list *timer)
timer_stats_timer_clear_start_info(timer);
if (timer_pending(timer)) {
base = lock_timer_base(timer, &flags);
if (timer_pending(timer)) {
detach_timer(timer, 1);
if (timer->expires == base->next_timer &&
!tbase_get_deferrable(timer->base))
base->next_timer = base->timer_jiffies;
ret = 1;
}
ret = detach_if_pending(timer, base, true);
spin_unlock_irqrestore(&base->lock, flags);
}
@ -990,19 +1008,10 @@ int try_to_del_timer_sync(struct timer_list *timer)
base = lock_timer_base(timer, &flags);
if (base->running_timer == timer)
goto out;
timer_stats_timer_clear_start_info(timer);
ret = 0;
if (timer_pending(timer)) {
detach_timer(timer, 1);
if (timer->expires == base->next_timer &&
!tbase_get_deferrable(timer->base))
base->next_timer = base->timer_jiffies;
ret = 1;
if (base->running_timer != timer) {
timer_stats_timer_clear_start_info(timer);
ret = detach_if_pending(timer, base, true);
}
out:
spin_unlock_irqrestore(&base->lock, flags);
return ret;
@ -1089,7 +1098,8 @@ static int cascade(struct tvec_base *base, struct tvec *tv, int index)
*/
list_for_each_entry_safe(timer, tmp, &tv_list, entry) {
BUG_ON(tbase_get_base(timer->base) != base);
internal_add_timer(base, timer);
/* No accounting, while moving them */
__internal_add_timer(base, timer);
}
return index;
@ -1178,7 +1188,7 @@ static inline void __run_timers(struct tvec_base *base)
timer_stats_account_timer(timer);
base->running_timer = timer;
detach_timer(timer, 1);
detach_expired_timer(timer, base);
spin_unlock_irq(&base->lock);
call_timer_fn(timer, fn, data);
@ -1316,18 +1326,21 @@ static unsigned long cmp_next_hrtimer_event(unsigned long now,
unsigned long get_next_timer_interrupt(unsigned long now)
{
struct tvec_base *base = __this_cpu_read(tvec_bases);
unsigned long expires;
unsigned long expires = now + NEXT_TIMER_MAX_DELTA;
/*
* Pretend that there is no timer pending if the cpu is offline.
* Possible pending timers will be migrated later to an active cpu.
*/
if (cpu_is_offline(smp_processor_id()))
return now + NEXT_TIMER_MAX_DELTA;
return expires;
spin_lock(&base->lock);
if (time_before_eq(base->next_timer, base->timer_jiffies))
base->next_timer = __next_timer_interrupt(base);
expires = base->next_timer;
if (base->active_timers) {
if (time_before_eq(base->next_timer, base->timer_jiffies))
base->next_timer = __next_timer_interrupt(base);
expires = base->next_timer;
}
spin_unlock(&base->lock);
if (time_before_eq(expires, now))
@ -1704,6 +1717,7 @@ static int __cpuinit init_timers_cpu(int cpu)
base->timer_jiffies = jiffies;
base->next_timer = base->timer_jiffies;
base->active_timers = 0;
return 0;
}
@ -1714,11 +1728,9 @@ static void migrate_timer_list(struct tvec_base *new_base, struct list_head *hea
while (!list_empty(head)) {
timer = list_first_entry(head, struct timer_list, entry);
detach_timer(timer, 0);
/* We ignore the accounting on the dying cpu */
detach_timer(timer, false);
timer_set_base(timer, new_base);
if (time_before(timer->expires, new_base->next_timer) &&
!tbase_get_deferrable(timer->base))
new_base->next_timer = timer->expires;
internal_add_timer(new_base, timer);
}
}