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author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-06 13:12:36 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-06 13:12:36 -0700 |
commit | af390084359a5de20046c901529b2b6a50b941cb (patch) | |
tree | b73a6261d1b1f9fb34432cc9a47411a49330b8dc /kernel/timer.c | |
parent | 7645e4320497b35ce9fb6c2269ebcd57af9fe735 (diff) | |
parent | 0fcb80818bc3ade5befd409051089f710adcf7b0 (diff) | |
download | linux-stable-af390084359a5de20046c901529b2b6a50b941cb.tar.gz linux-stable-af390084359a5de20046c901529b2b6a50b941cb.tar.bz2 linux-stable-af390084359a5de20046c901529b2b6a50b941cb.zip |
Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
Documentation: Add timers/timers-howto.txt
timer: Added usleep_range timer
Revert "timer: Added usleep[_range] timer"
clockevents: Remove the per cpu tick skew
posix_timer: Move copy_to_user(created_timer_id) down in timer_create()
timer: Added usleep[_range] timer
timers: Document meaning of deferrable timer
Diffstat (limited to 'kernel/timer.c')
-rw-r--r-- | kernel/timer.c | 31 |
1 files changed, 29 insertions, 2 deletions
diff --git a/kernel/timer.c b/kernel/timer.c index d61d16da0b64..f1b8afe1ad86 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -90,8 +90,13 @@ static DEFINE_PER_CPU(struct tvec_base *, tvec_bases) = &boot_tvec_bases; /* * Note that all tvec_bases are 2 byte aligned and lower bit of - * base in timer_list is guaranteed to be zero. Use the LSB for - * the new flag to indicate whether the timer is deferrable + * base in timer_list is guaranteed to be zero. Use the LSB to + * indicate whether the timer is deferrable. + * + * A deferrable timer will work normally when the system is busy, but + * will not cause a CPU to come out of idle just to service it; instead, + * the timer will be serviced when the CPU eventually wakes up with a + * subsequent non-deferrable timer. */ #define TBASE_DEFERRABLE_FLAG (0x1) @@ -1758,3 +1763,25 @@ unsigned long msleep_interruptible(unsigned int msecs) } EXPORT_SYMBOL(msleep_interruptible); + +static int __sched do_usleep_range(unsigned long min, unsigned long max) +{ + ktime_t kmin; + unsigned long delta; + + kmin = ktime_set(0, min * NSEC_PER_USEC); + delta = (max - min) * NSEC_PER_USEC; + return schedule_hrtimeout_range(&kmin, delta, HRTIMER_MODE_REL); +} + +/** + * usleep_range - Drop in replacement for udelay where wakeup is flexible + * @min: Minimum time in usecs to sleep + * @max: Maximum time in usecs to sleep + */ +void usleep_range(unsigned long min, unsigned long max) +{ + __set_current_state(TASK_UNINTERRUPTIBLE); + do_usleep_range(min, max); +} +EXPORT_SYMBOL(usleep_range); |