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hrtimer: make the futex() system call use the per process slack value

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This patch makes the futex() system call use the per process
slack value; with this users are able to externally control existing
applications to reduce the wakeup rate.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
This commit is contained in:
Arjan van de Ven 2008-09-08 09:03:57 -07:00
parent 3bd012060f
commit ae4b748e81
1 changed files with 5 additions and 1 deletions
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6
kernel/futex.c
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@ -1296,10 +1296,14 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared,
if (!abs_time)
schedule();
else {
unsigned long slack;
slack = current->timer_slack_ns;
if (rt_task(current))
slack = 0;
hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC,
HRTIMER_MODE_ABS);
hrtimer_init_sleeper(&t, current);
hrtimer_set_expires(&t.timer, *abs_time);
hrtimer_set_expires_range_ns(&t.timer, *abs_time, slack);
hrtimer_start_expires(&t.timer, HRTIMER_MODE_ABS);
if (!hrtimer_active(&t.timer))