From e4aa358b6c23f98b2715594f6b1e9a4996a55f04 Mon Sep 17 00:00:00 2001 From: Kirill Tkhai Date: Thu, 6 Mar 2014 13:31:55 +0400 Subject: [PATCH] sched/fair: Push down check for high priority class task into idle_balance() We close idle_exit_fair() bracket in case of we've pulled something or we've received task of high priority class. Signed-off-by: Kirill Tkhai Signed-off-by: Peter Zijlstra Cc: Vincent Guittot Link: http://lkml.kernel.org/r/1394098315.19290.10.camel@tkhai Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 15 ++++++++++----- kernel/sched/idle_task.c | 1 - 2 files changed, 10 insertions(+), 6 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index d8482e1c575e..b956e70fc503 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4787,17 +4787,16 @@ pick_next_task_fair(struct rq *rq, struct task_struct *prev) return p; idle: + new_tasks = idle_balance(rq); /* * Because idle_balance() releases (and re-acquires) rq->lock, it is * possible for any higher priority task to appear. In that case we * must re-start the pick_next_entity() loop. */ - new_tasks = idle_balance(rq); - - if (rq->nr_running != rq->cfs.h_nr_running) + if (new_tasks < 0) return RETRY_TASK; - if (new_tasks) + if (new_tasks > 0) goto again; return NULL; @@ -6728,8 +6727,14 @@ static int idle_balance(struct rq *this_rq) this_rq->max_idle_balance_cost = curr_cost; out: - if (pulled_task) + /* Is there a task of a high priority class? */ + if (this_rq->nr_running != this_rq->cfs.h_nr_running) + pulled_task = -1; + + if (pulled_task) { + idle_exit_fair(this_rq); this_rq->idle_stamp = 0; + } return pulled_task; } diff --git a/kernel/sched/idle_task.c b/kernel/sched/idle_task.c index 1f3725882838..879f2b75266a 100644 --- a/kernel/sched/idle_task.c +++ b/kernel/sched/idle_task.c @@ -29,7 +29,6 @@ pick_next_task_idle(struct rq *rq, struct task_struct *prev) put_prev_task(rq, prev); schedstat_inc(rq, sched_goidle); - idle_enter_fair(rq); return rq->idle; }