Commit 92c1d3ed authored by John Stultz's avatar John Stultz
Browse files

time: Remove most of xtime_lock usage in timekeeping.c 



Now that ntp.c's locking is reworked, we can remove most
of the xtime_lock usage in timekeeping.c

The remaining xtime_lock presence is really for jiffies access
and the global load calculation.

CC: Thomas Gleixner <tglx@linutronix.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
parent bd331268

kernel/time/timekeeping.c

+15 −29
Original line number Diff line number Diff line
@@ -172,7 +172,6 @@ static inline s64 timekeeping_get_ns_raw(void) 
	return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);

}



/* must hold xtime_lock */

void timekeeping_leap_insert(int leapsecond)

{

	unsigned long flags;
@@ -372,13 +371,12 @@ EXPORT_SYMBOL(do_gettimeofday); 
int do_settimeofday(const struct timespec *tv)

{

	struct timespec ts_delta;

	unsigned long flags1,flags2;

	unsigned long flags;



	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)

		return -EINVAL;



	write_seqlock_irqsave(&xtime_lock, flags1);

	write_seqlock_irqsave(&timekeeper.lock, flags2);

	write_seqlock_irqsave(&timekeeper.lock, flags);



	timekeeping_forward_now();
@@ -395,8 +393,7 @@ int do_settimeofday(const struct timespec *tv) 
	update_vsyscall(&timekeeper.xtime, &timekeeper.wall_to_monotonic,

			timekeeper.clock, timekeeper.mult);



	write_sequnlock_irqrestore(&timekeeper.lock, flags2);

	write_sequnlock_irqrestore(&xtime_lock, flags1);

	write_sequnlock_irqrestore(&timekeeper.lock, flags);



	/* signal hrtimers about time change */

	clock_was_set();
@@ -415,13 +412,12 @@ EXPORT_SYMBOL(do_settimeofday); 
 */

int timekeeping_inject_offset(struct timespec *ts)

{

	unsigned long flags1,flags2;

	unsigned long flags;



	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)

		return -EINVAL;



	write_seqlock_irqsave(&xtime_lock, flags1);

	write_seqlock_irqsave(&timekeeper.lock, flags2);

	write_seqlock_irqsave(&timekeeper.lock, flags);



	timekeeping_forward_now();
@@ -435,8 +431,7 @@ int timekeeping_inject_offset(struct timespec *ts) 
	update_vsyscall(&timekeeper.xtime, &timekeeper.wall_to_monotonic,

			timekeeper.clock, timekeeper.mult);



	write_sequnlock_irqrestore(&timekeeper.lock, flags2);

	write_sequnlock_irqrestore(&xtime_lock, flags1);

	write_sequnlock_irqrestore(&timekeeper.lock, flags);



	/* signal hrtimers about time change */

	clock_was_set();
@@ -598,9 +593,7 @@ void __init timekeeping_init(void) 


	seqlock_init(&timekeeper.lock);



	write_seqlock_irqsave(&xtime_lock, flags);

	ntp_init();

	write_sequnlock_irqrestore(&xtime_lock, flags);



	write_seqlock_irqsave(&timekeeper.lock, flags);

	clock = clocksource_default_clock();
@@ -661,7 +654,7 @@ static void __timekeeping_inject_sleeptime(struct timespec *delta) 
 */

void timekeeping_inject_sleeptime(struct timespec *delta)

{

	unsigned long flags1,flags2;

	unsigned long flags;

	struct timespec ts;



	/* Make sure we don't set the clock twice */
@@ -669,8 +662,7 @@ void timekeeping_inject_sleeptime(struct timespec *delta) 
	if (!(ts.tv_sec == 0 && ts.tv_nsec == 0))

		return;



	write_seqlock_irqsave(&xtime_lock, flags1);

	write_seqlock_irqsave(&timekeeper.lock, flags2);

	write_seqlock_irqsave(&timekeeper.lock, flags);



	timekeeping_forward_now();
@@ -681,8 +673,7 @@ void timekeeping_inject_sleeptime(struct timespec *delta) 
	update_vsyscall(&timekeeper.xtime, &timekeeper.wall_to_monotonic,

			timekeeper.clock, timekeeper.mult);



	write_sequnlock_irqrestore(&timekeeper.lock, flags2);

	write_sequnlock_irqrestore(&xtime_lock, flags1);

	write_sequnlock_irqrestore(&timekeeper.lock, flags);



	/* signal hrtimers about time change */

	clock_was_set();
@@ -698,15 +689,14 @@ void timekeeping_inject_sleeptime(struct timespec *delta) 
 */

static void timekeeping_resume(void)

{

	unsigned long flags1,flags2;

	unsigned long flags;

	struct timespec ts;



	read_persistent_clock(&ts);



	clocksource_resume();



	write_seqlock_irqsave(&xtime_lock, flags1);

	write_seqlock_irqsave(&timekeeper.lock, flags2);

	write_seqlock_irqsave(&timekeeper.lock, flags);



	if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {

		ts = timespec_sub(ts, timekeeping_suspend_time);
@@ -716,8 +706,7 @@ static void timekeeping_resume(void) 
	timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);

	timekeeper.ntp_error = 0;

	timekeeping_suspended = 0;

	write_sequnlock_irqrestore(&timekeeper.lock, flags2);

	write_sequnlock_irqrestore(&xtime_lock, flags1);

	write_sequnlock_irqrestore(&timekeeper.lock, flags);



	touch_softlockup_watchdog();
@@ -729,14 +718,13 @@ static void timekeeping_resume(void) 


static int timekeeping_suspend(void)

{

	unsigned long flags1,flags2;

	unsigned long flags;

	struct timespec		delta, delta_delta;

	static struct timespec	old_delta;



	read_persistent_clock(&timekeeping_suspend_time);



	write_seqlock_irqsave(&xtime_lock, flags1);

	write_seqlock_irqsave(&timekeeper.lock, flags2);

	write_seqlock_irqsave(&timekeeper.lock, flags);

	timekeeping_forward_now();

	timekeeping_suspended = 1;
@@ -759,8 +747,7 @@ static int timekeeping_suspend(void) 
		timekeeping_suspend_time =

			timespec_add(timekeeping_suspend_time, delta_delta);

	}

	write_sequnlock_irqrestore(&timekeeper.lock, flags2);

	write_sequnlock_irqrestore(&xtime_lock, flags1);

	write_sequnlock_irqrestore(&timekeeper.lock, flags);



	clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);

	clocksource_suspend();
@@ -1006,7 +993,6 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift) 
/**

 * update_wall_time - Uses the current clocksource to increment the wall time

 *

 * Called from the timer interrupt, must hold a write on xtime_lock.

 */

static void update_wall_time(void)

{

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