From 6e82a3befe91423e501c2124312bd805be0048eb Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 9 Aug 2007 11:16:51 +0200 Subject: [PATCH] sched: optimize update_rq_clock() calls in the load-balancer optimize update_rq_clock() calls in the load-balancer: update them right after locking the runqueue(s) so that the pull functions do not have to call it. Signed-off-by: Ingo Molnar --- kernel/sched.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index 9ccd91e5b65b..afc59f274e58 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2017,6 +2017,8 @@ static void double_rq_lock(struct rq *rq1, struct rq *rq2) spin_lock(&rq1->lock); } } + update_rq_clock(rq1); + update_rq_clock(rq2); } /* @@ -2113,10 +2115,8 @@ void sched_exec(void) static void pull_task(struct rq *src_rq, struct task_struct *p, struct rq *this_rq, int this_cpu) { - update_rq_clock(src_rq); deactivate_task(src_rq, p, 0); set_task_cpu(p, this_cpu); - __update_rq_clock(this_rq); activate_task(this_rq, p, 0); /* * Note that idle threads have a prio of MAX_PRIO, for this test @@ -2798,6 +2798,8 @@ load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd) if (busiest->nr_running > 1) { /* Attempt to move tasks */ double_lock_balance(this_rq, busiest); + /* this_rq->clock is already updated */ + update_rq_clock(busiest); ld_moved = move_tasks(this_rq, this_cpu, busiest, imbalance, sd, CPU_NEWLY_IDLE, &all_pinned); @@ -2895,6 +2897,8 @@ static void active_load_balance(struct rq *busiest_rq, int busiest_cpu) /* move a task from busiest_rq to target_rq */ double_lock_balance(busiest_rq, target_rq); + update_rq_clock(busiest_rq); + update_rq_clock(target_rq); /* Search for an sd spanning us and the target CPU. */ for_each_domain(target_cpu, sd) { @@ -4962,13 +4966,11 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) goto out; on_rq = p->se.on_rq; - if (on_rq) { - update_rq_clock(rq_src); + if (on_rq) deactivate_task(rq_src, p, 0); - } + set_task_cpu(p, dest_cpu); if (on_rq) { - update_rq_clock(rq_dest); activate_task(rq_dest, p, 0); check_preempt_curr(rq_dest, p); } -- GitLab