From ae4b748e81b7e366f04f55229d5e372e372c33af Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Mon, 8 Sep 2008 09:03:57 -0700 Subject: [PATCH] hrtimer: make the futex() system call use the per process slack value 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 --- kernel/futex.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/futex.c b/kernel/futex.c index 4cd5b4319b04..8af10027514b 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -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))