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Commit 351b3f7a authored by Carsten Emde's avatar Carsten Emde Committed by Thomas Gleixner
Browse files

hrtimers: Provide schedule_hrtimeout for CLOCK_REALTIME 



The current version of schedule_hrtimeout() always uses the
monotonic clock. Some system calls such as mq_timedsend()
and mq_timedreceive(), however, require the use of the wall
clock due to the definition of the system call.

This patch provides the infrastructure to use schedule_hrtimeout() 
with a CLOCK_REALTIME timer.

Signed-off-by: default avatarCarsten Emde <C.Emde@osadl.org>
Tested-by: default avatarPradyumna Sampath <pradysam@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Veen <arjan@infradead.org>
LKML-Reference: <20100402204331.167439615@osadl.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 3bbb9ec9

include/linux/hrtimer.h

+2 −0
Original line number Diff line number Diff line
@@ -422,6 +422,8 @@ extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, 


extern int schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,

						const enum hrtimer_mode mode);

extern int schedule_hrtimeout_range_clock(ktime_t *expires,

		unsigned long delta, const enum hrtimer_mode mode, int clock);

extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode);



/* Soft interrupt function to run the hrtimer queues: */

kernel/hrtimer.c

+41 −26
Original line number Diff line number Diff line
@@ -1749,35 +1749,15 @@ void __init hrtimers_init(void) 
}



/**

 * schedule_hrtimeout_range - sleep until timeout

 * schedule_hrtimeout_range_clock - sleep until timeout

 * @expires:	timeout value (ktime_t)

 * @delta:	slack in expires timeout (ktime_t)

 * @mode:	timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL

 *

 * Make the current task sleep until the given expiry time has

 * elapsed. The routine will return immediately unless

 * the current task state has been set (see set_current_state()).

 *

 * The @delta argument gives the kernel the freedom to schedule the

 * actual wakeup to a time that is both power and performance friendly.

 * The kernel give the normal best effort behavior for "@expires+@delta",

 * but may decide to fire the timer earlier, but no earlier than @expires.

 *

 * You can set the task state as follows -

 *

 * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to

 * pass before the routine returns.

 *

 * %TASK_INTERRUPTIBLE - the routine may return early if a signal is

 * delivered to the current task.

 *

 * The current task state is guaranteed to be TASK_RUNNING when this

 * routine returns.

 *

 * Returns 0 when the timer has expired otherwise -EINTR

 * @clock:	timer clock, CLOCK_MONOTONIC or CLOCK_REALTIME

 */

int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,

			       const enum hrtimer_mode mode)

int __sched

schedule_hrtimeout_range_clock(ktime_t *expires, unsigned long delta,

			       const enum hrtimer_mode mode, int clock)

{

	struct hrtimer_sleeper t;
@@ -1799,7 +1779,7 @@ int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta, 
		return -EINTR;

	}



	hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC, mode);

	hrtimer_init_on_stack(&t.timer, clock, mode);

	hrtimer_set_expires_range_ns(&t.timer, *expires, delta);



	hrtimer_init_sleeper(&t, current);
@@ -1818,6 +1798,41 @@ int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta, 


	return !t.task ? 0 : -EINTR;

}



/**

 * schedule_hrtimeout_range - sleep until timeout

 * @expires:	timeout value (ktime_t)

 * @delta:	slack in expires timeout (ktime_t)

 * @mode:	timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL

 *

 * Make the current task sleep until the given expiry time has

 * elapsed. The routine will return immediately unless

 * the current task state has been set (see set_current_state()).

 *

 * The @delta argument gives the kernel the freedom to schedule the

 * actual wakeup to a time that is both power and performance friendly.

 * The kernel give the normal best effort behavior for "@expires+@delta",

 * but may decide to fire the timer earlier, but no earlier than @expires.

 *

 * You can set the task state as follows -

 *

 * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to

 * pass before the routine returns.

 *

 * %TASK_INTERRUPTIBLE - the routine may return early if a signal is

 * delivered to the current task.

 *

 * The current task state is guaranteed to be TASK_RUNNING when this

 * routine returns.

 *

 * Returns 0 when the timer has expired otherwise -EINTR

 */

int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,

				     const enum hrtimer_mode mode)

{

	return schedule_hrtimeout_range_clock(expires, delta, mode,

					      CLOCK_MONOTONIC);

}

EXPORT_SYMBOL_GPL(schedule_hrtimeout_range);



/**