From 8f4d37ec073c17e2d4aa8851df5837d798606d6f Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 25 Jan 2008 21:08:29 +0100 Subject: sched: high-res preemption tick Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/sched_idletask.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/sched_idletask.c') diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c index ef7a2661fa10..2bcafa375633 100644 --- a/kernel/sched_idletask.c +++ b/kernel/sched_idletask.c @@ -61,7 +61,7 @@ move_one_task_idle(struct rq *this_rq, int this_cpu, struct rq *busiest, } #endif -static void task_tick_idle(struct rq *rq, struct task_struct *curr) +static void task_tick_idle(struct rq *rq, struct task_struct *curr, int queued) { } -- cgit v1.2.3