linux/debian/patches/features/all/rt/0023-timekeeping-Split-xtim...

533 lines
16 KiB
Diff

From 6279b0161cf978d1c6c12a7991cc27676ad1fbc2 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 1 Mar 2012 15:14:06 +0100
Subject: [PATCH 023/283] timekeeping: Split xtime_lock
xtime_lock is going to be split apart in mainline, so we can shorten
the seqcount protected regions and avoid updating seqcount in some
code pathes. This is a straight forward split, so we can avoid the
whole mess with raw seqlocks for RT.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/time/jiffies.c | 4 +-
kernel/time/ntp.c | 23 ++++++++---
kernel/time/tick-common.c | 10 +++--
kernel/time/tick-internal.h | 3 +-
kernel/time/tick-sched.c | 16 +++++---
kernel/time/timekeeping.c | 90 +++++++++++++++++++++++++------------------
6 files changed, 89 insertions(+), 57 deletions(-)
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index a470154..21940eb 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -74,9 +74,9 @@ u64 get_jiffies_64(void)
u64 ret;
do {
- seq = read_seqbegin(&xtime_lock);
+ seq = read_seqcount_begin(&xtime_seq);
ret = jiffies_64;
- } while (read_seqretry(&xtime_lock, seq));
+ } while (read_seqcount_retry(&xtime_seq, seq));
return ret;
}
EXPORT_SYMBOL(get_jiffies_64);
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index f1eb182..09079b7 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -362,6 +362,9 @@ int second_overflow(unsigned long secs)
int leap = 0;
s64 delta;
+ raw_spin_lock(&xtime_lock);
+ write_seqcount_begin(&xtime_seq);
+
/*
* Leap second processing. If in leap-insert state at the end of the
* day, the system clock is set back one second; if in leap-delete
@@ -402,6 +405,8 @@ int second_overflow(unsigned long secs)
break;
}
+ write_seqcount_end(&xtime_seq);
+ raw_spin_unlock(&xtime_lock);
/* Bump the maxerror field */
time_maxerror += MAXFREQ / NSEC_PER_USEC;
@@ -623,7 +628,8 @@ int do_adjtimex(struct timex *txc)
getnstimeofday(&ts);
- write_seqlock_irq(&xtime_lock);
+ raw_spin_lock_irq(&xtime_lock);
+ write_seqcount_begin(&xtime_seq);
if (txc->modes & ADJ_ADJTIME) {
long save_adjust = time_adjust;
@@ -665,7 +671,8 @@ int do_adjtimex(struct timex *txc)
/* fill PPS status fields */
pps_fill_timex(txc);
- write_sequnlock_irq(&xtime_lock);
+ write_seqcount_end(&xtime_seq);
+ raw_spin_unlock_irq(&xtime_lock);
txc->time.tv_sec = ts.tv_sec;
txc->time.tv_usec = ts.tv_nsec;
@@ -863,7 +870,8 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
pts_norm = pps_normalize_ts(*phase_ts);
- write_seqlock_irqsave(&xtime_lock, flags);
+ raw_spin_lock_irqsave(&xtime_lock, flags);
+ write_seqcount_begin(&xtime_seq);
/* clear the error bits, they will be set again if needed */
time_status &= ~(STA_PPSJITTER | STA_PPSWANDER | STA_PPSERROR);
@@ -876,7 +884,8 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
* just start the frequency interval */
if (unlikely(pps_fbase.tv_sec == 0)) {
pps_fbase = *raw_ts;
- write_sequnlock_irqrestore(&xtime_lock, flags);
+ write_seqcount_end(&xtime_seq);
+ raw_spin_unlock_irqrestore(&xtime_lock, flags);
return;
}
@@ -891,7 +900,8 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
time_status |= STA_PPSJITTER;
/* restart the frequency calibration interval */
pps_fbase = *raw_ts;
- write_sequnlock_irqrestore(&xtime_lock, flags);
+ write_seqcount_end(&xtime_seq);
+ raw_spin_unlock_irqrestore(&xtime_lock, flags);
pr_err("hardpps: PPSJITTER: bad pulse\n");
return;
}
@@ -908,7 +918,8 @@ void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
hardpps_update_phase(pts_norm.nsec);
- write_sequnlock_irqrestore(&xtime_lock, flags);
+ write_seqcount_end(&xtime_seq);
+ raw_spin_unlock_irqrestore(&xtime_lock, flags);
}
EXPORT_SYMBOL(hardpps);
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index da6c9ec..39de540 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -63,13 +63,15 @@ int tick_is_oneshot_available(void)
static void tick_periodic(int cpu)
{
if (tick_do_timer_cpu == cpu) {
- write_seqlock(&xtime_lock);
+ raw_spin_lock(&xtime_lock);
+ write_seqcount_begin(&xtime_seq);
/* Keep track of the next tick event */
tick_next_period = ktime_add(tick_next_period, tick_period);
do_timer(1);
- write_sequnlock(&xtime_lock);
+ write_seqcount_end(&xtime_seq);
+ raw_spin_unlock(&xtime_lock);
}
update_process_times(user_mode(get_irq_regs()));
@@ -130,9 +132,9 @@ void tick_setup_periodic(struct clock_event_device *dev, int broadcast)
ktime_t next;
do {
- seq = read_seqbegin(&xtime_lock);
+ seq = read_seqcount_begin(&xtime_seq);
next = tick_next_period;
- } while (read_seqretry(&xtime_lock, seq));
+ } while (read_seqcount_retry(&xtime_seq, seq));
clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
index 4e265b9..c91100d 100644
--- a/kernel/time/tick-internal.h
+++ b/kernel/time/tick-internal.h
@@ -141,4 +141,5 @@ static inline int tick_device_is_functional(struct clock_event_device *dev)
#endif
extern void do_timer(unsigned long ticks);
-extern seqlock_t xtime_lock;
+extern raw_spinlock_t xtime_lock;
+extern seqcount_t xtime_seq;
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 9955ebd..f8d1e36 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -56,7 +56,8 @@ static void tick_do_update_jiffies64(ktime_t now)
return;
/* Reevalute with xtime_lock held */
- write_seqlock(&xtime_lock);
+ raw_spin_lock(&xtime_lock);
+ write_seqcount_begin(&xtime_seq);
delta = ktime_sub(now, last_jiffies_update);
if (delta.tv64 >= tick_period.tv64) {
@@ -79,7 +80,8 @@ static void tick_do_update_jiffies64(ktime_t now)
/* Keep the tick_next_period variable up to date */
tick_next_period = ktime_add(last_jiffies_update, tick_period);
}
- write_sequnlock(&xtime_lock);
+ write_seqcount_end(&xtime_seq);
+ raw_spin_unlock(&xtime_lock);
}
/*
@@ -89,12 +91,14 @@ static ktime_t tick_init_jiffy_update(void)
{
ktime_t period;
- write_seqlock(&xtime_lock);
+ raw_spin_lock(&xtime_lock);
+ write_seqcount_begin(&xtime_seq);
/* Did we start the jiffies update yet ? */
if (last_jiffies_update.tv64 == 0)
last_jiffies_update = tick_next_period;
period = last_jiffies_update;
- write_sequnlock(&xtime_lock);
+ write_seqcount_end(&xtime_seq);
+ raw_spin_unlock(&xtime_lock);
return period;
}
@@ -345,11 +349,11 @@ void tick_nohz_stop_sched_tick(int inidle)
ts->idle_calls++;
/* Read jiffies and the time when jiffies were updated last */
do {
- seq = read_seqbegin(&xtime_lock);
+ seq = read_seqcount_begin(&xtime_seq);
last_update = last_jiffies_update;
last_jiffies = jiffies;
time_delta = timekeeping_max_deferment();
- } while (read_seqretry(&xtime_lock, seq));
+ } while (read_seqcount_retry(&xtime_seq, seq));
if (rcu_needs_cpu(cpu) || printk_needs_cpu(cpu) ||
arch_needs_cpu(cpu)) {
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 03e67d4..03493fd 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -139,8 +139,8 @@ static inline s64 timekeeping_get_ns_raw(void)
* This read-write spinlock protects us from races in SMP while
* playing with xtime.
*/
-__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
-
+__cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(xtime_lock);
+seqcount_t xtime_seq;
/*
* The current time
@@ -242,7 +242,7 @@ void getnstimeofday(struct timespec *ts)
WARN_ON(timekeeping_suspended);
do {
- seq = read_seqbegin(&xtime_lock);
+ seq = read_seqcount_begin(&xtime_seq);
*ts = xtime;
nsecs = timekeeping_get_ns();
@@ -250,7 +250,7 @@ void getnstimeofday(struct timespec *ts)
/* If arch requires, add in gettimeoffset() */
nsecs += arch_gettimeoffset();
- } while (read_seqretry(&xtime_lock, seq));
+ } while (read_seqcount_retry(&xtime_seq, seq));
timespec_add_ns(ts, nsecs);
}
@@ -265,14 +265,14 @@ ktime_t ktime_get(void)
WARN_ON(timekeeping_suspended);
do {
- seq = read_seqbegin(&xtime_lock);
+ seq = read_seqcount_begin(&xtime_seq);
secs = xtime.tv_sec + wall_to_monotonic.tv_sec;
nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec;
nsecs += timekeeping_get_ns();
/* If arch requires, add in gettimeoffset() */
nsecs += arch_gettimeoffset();
- } while (read_seqretry(&xtime_lock, seq));
+ } while (read_seqcount_retry(&xtime_seq, seq));
/*
* Use ktime_set/ktime_add_ns to create a proper ktime on
* 32-bit architectures without CONFIG_KTIME_SCALAR.
@@ -298,14 +298,14 @@ void ktime_get_ts(struct timespec *ts)
WARN_ON(timekeeping_suspended);
do {
- seq = read_seqbegin(&xtime_lock);
+ seq = read_seqcount_begin(&xtime_seq);
*ts = xtime;
tomono = wall_to_monotonic;
nsecs = timekeeping_get_ns();
/* If arch requires, add in gettimeoffset() */
nsecs += arch_gettimeoffset();
- } while (read_seqretry(&xtime_lock, seq));
+ } while (read_seqcount_retry(&xtime_seq, seq));
set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
ts->tv_nsec + tomono.tv_nsec + nsecs);
@@ -333,7 +333,7 @@ void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
do {
u32 arch_offset;
- seq = read_seqbegin(&xtime_lock);
+ seq = read_seqcount_begin(&xtime_seq);
*ts_raw = raw_time;
*ts_real = xtime;
@@ -346,7 +346,7 @@ void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
nsecs_raw += arch_offset;
nsecs_real += arch_offset;
- } while (read_seqretry(&xtime_lock, seq));
+ } while (read_seqcount_retry(&xtime_seq, seq));
timespec_add_ns(ts_raw, nsecs_raw);
timespec_add_ns(ts_real, nsecs_real);
@@ -385,7 +385,8 @@ int do_settimeofday(const struct timespec *tv)
if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
return -EINVAL;
- write_seqlock_irqsave(&xtime_lock, flags);
+ raw_spin_lock_irqsave(&xtime_lock, flags);
+ write_seqcount_begin(&xtime_seq);
timekeeping_forward_now();
@@ -397,7 +398,8 @@ int do_settimeofday(const struct timespec *tv)
timekeeping_update(true);
- write_sequnlock_irqrestore(&xtime_lock, flags);
+ write_seqcount_end(&xtime_seq);
+ raw_spin_unlock_irqrestore(&xtime_lock, flags);
/* signal hrtimers about time change */
clock_was_set();
@@ -421,7 +423,8 @@ int timekeeping_inject_offset(struct timespec *ts)
if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
return -EINVAL;
- write_seqlock_irqsave(&xtime_lock, flags);
+ raw_spin_lock_irqsave(&xtime_lock, flags);
+ write_seqcount_begin(&xtime_seq);
timekeeping_forward_now();
@@ -430,7 +433,8 @@ int timekeeping_inject_offset(struct timespec *ts)
timekeeping_update(true);
- write_sequnlock_irqrestore(&xtime_lock, flags);
+ write_seqcount_end(&xtime_seq);
+ raw_spin_unlock_irqrestore(&xtime_lock, flags);
/* signal hrtimers about time change */
clock_was_set();
@@ -502,11 +506,11 @@ void getrawmonotonic(struct timespec *ts)
s64 nsecs;
do {
- seq = read_seqbegin(&xtime_lock);
+ seq = read_seqcount_begin(&xtime_seq);
nsecs = timekeeping_get_ns_raw();
*ts = raw_time;
- } while (read_seqretry(&xtime_lock, seq));
+ } while (read_seqcount_retry(&xtime_seq, seq));
timespec_add_ns(ts, nsecs);
}
@@ -522,11 +526,11 @@ int timekeeping_valid_for_hres(void)
int ret;
do {
- seq = read_seqbegin(&xtime_lock);
+ seq = read_seqcount_begin(&xtime_seq);
ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
- } while (read_seqretry(&xtime_lock, seq));
+ } while (read_seqcount_retry(&xtime_seq, seq));
return ret;
}
@@ -584,7 +588,8 @@ void __init timekeeping_init(void)
read_persistent_clock(&now);
read_boot_clock(&boot);
- write_seqlock_irqsave(&xtime_lock, flags);
+ raw_spin_lock_irqsave(&xtime_lock, flags);
+ write_seqcount_begin(&xtime_seq);
ntp_init();
@@ -606,7 +611,8 @@ void __init timekeeping_init(void)
update_rt_offset();
total_sleep_time.tv_sec = 0;
total_sleep_time.tv_nsec = 0;
- write_sequnlock_irqrestore(&xtime_lock, flags);
+ write_seqcount_end(&xtime_seq);
+ raw_spin_unlock_irqrestore(&xtime_lock, flags);
}
/* time in seconds when suspend began */
@@ -659,14 +665,16 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
if (!(ts.tv_sec == 0 && ts.tv_nsec == 0))
return;
- write_seqlock_irqsave(&xtime_lock, flags);
+ raw_spin_lock_irqsave(&xtime_lock, flags);
+ write_seqcount_begin(&xtime_seq);
timekeeping_forward_now();
__timekeeping_inject_sleeptime(delta);
timekeeping_update(true);
- write_sequnlock_irqrestore(&xtime_lock, flags);
+ write_seqcount_end(&xtime_seq);
+ raw_spin_unlock_irqrestore(&xtime_lock, flags);
/* signal hrtimers about time change */
clock_was_set();
@@ -689,7 +697,8 @@ static void timekeeping_resume(void)
clocksource_resume();
- write_seqlock_irqsave(&xtime_lock, flags);
+ raw_spin_lock_irqsave(&xtime_lock, flags);
+ write_seqcount_begin(&xtime_seq);
if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
ts = timespec_sub(ts, timekeeping_suspend_time);
@@ -700,7 +709,8 @@ static void timekeeping_resume(void)
timekeeper.ntp_error = 0;
timekeeping_suspended = 0;
timekeeping_update(false);
- write_sequnlock_irqrestore(&xtime_lock, flags);
+ write_seqcount_end(&xtime_seq);
+ raw_spin_unlock_irqrestore(&xtime_lock, flags);
touch_softlockup_watchdog();
@@ -718,7 +728,8 @@ static int timekeeping_suspend(void)
read_persistent_clock(&timekeeping_suspend_time);
- write_seqlock_irqsave(&xtime_lock, flags);
+ raw_spin_lock_irqsave(&xtime_lock, flags);
+ write_seqcount_begin(&xtime_seq);
timekeeping_forward_now();
timekeeping_suspended = 1;
@@ -741,7 +752,8 @@ static int timekeeping_suspend(void)
timekeeping_suspend_time =
timespec_add(timekeeping_suspend_time, delta_delta);
}
- write_sequnlock_irqrestore(&xtime_lock, flags);
+ write_seqcount_end(&xtime_seq);
+ raw_spin_unlock_irqrestore(&xtime_lock, flags);
clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
clocksource_suspend();
@@ -1126,13 +1138,13 @@ void get_monotonic_boottime(struct timespec *ts)
WARN_ON(timekeeping_suspended);
do {
- seq = read_seqbegin(&xtime_lock);
+ seq = read_seqcount_begin(&xtime_seq);
*ts = xtime;
tomono = wall_to_monotonic;
sleep = total_sleep_time;
nsecs = timekeeping_get_ns();
- } while (read_seqretry(&xtime_lock, seq));
+ } while (read_seqcount_retry(&xtime_seq, seq));
set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec + sleep.tv_sec,
ts->tv_nsec + tomono.tv_nsec + sleep.tv_nsec + nsecs);
@@ -1183,10 +1195,10 @@ struct timespec current_kernel_time(void)
unsigned long seq;
do {
- seq = read_seqbegin(&xtime_lock);
+ seq = read_seqcount_begin(&xtime_seq);
now = xtime;
- } while (read_seqretry(&xtime_lock, seq));
+ } while (read_seqcount_retry(&xtime_seq, seq));
return now;
}
@@ -1198,11 +1210,11 @@ struct timespec get_monotonic_coarse(void)
unsigned long seq;
do {
- seq = read_seqbegin(&xtime_lock);
+ seq = read_seqcount_begin(&xtime_seq);
now = xtime;
mono = wall_to_monotonic;
- } while (read_seqretry(&xtime_lock, seq));
+ } while (read_seqcount_retry(&xtime_seq, seq));
set_normalized_timespec(&now, now.tv_sec + mono.tv_sec,
now.tv_nsec + mono.tv_nsec);
@@ -1234,11 +1246,11 @@ void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
unsigned long seq;
do {
- seq = read_seqbegin(&xtime_lock);
+ seq = read_seqcount_begin(&xtime_seq);
*xtim = xtime;
*wtom = wall_to_monotonic;
*sleep = total_sleep_time;
- } while (read_seqretry(&xtime_lock, seq));
+ } while (read_seqcount_retry(&xtime_seq, seq));
}
#ifdef CONFIG_HIGH_RES_TIMERS
@@ -1284,9 +1296,9 @@ ktime_t ktime_get_monotonic_offset(void)
struct timespec wtom;
do {
- seq = read_seqbegin(&xtime_lock);
+ seq = read_seqcount_begin(&xtime_seq);
wtom = wall_to_monotonic;
- } while (read_seqretry(&xtime_lock, seq));
+ } while (read_seqcount_retry(&xtime_seq, seq));
return timespec_to_ktime(wtom);
}
@@ -1298,7 +1310,9 @@ ktime_t ktime_get_monotonic_offset(void)
*/
void xtime_update(unsigned long ticks)
{
- write_seqlock(&xtime_lock);
+ raw_spin_lock(&xtime_lock);
+ write_seqcount_begin(&xtime_seq);
do_timer(ticks);
- write_sequnlock(&xtime_lock);
+ write_seqcount_end(&xtime_seq);
+ raw_spin_unlock(&xtime_lock);
}