From: Peter Zijlstra <peterz@infradead.org>
To: linux-kernel@vger.kernel.org
Cc: mingo@kernel.org, daniel.lezcano@linaro.org, pjt@google.com,
bsegall@google.com, Vincent Guittot <vincent.guittot@linaro.org>,
Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH 4/9] sched: Clean up idle task SMP logic
Date: Tue, 21 Jan 2014 12:17:58 +0100 [thread overview]
Message-ID: <20140121112258.459329467@infradead.org> (raw)
In-Reply-To: 20140121111754.580142558@infradead.org
[-- Attachment #1: peter_zijlstra-sched-clean_up_idle_task_smp_logic.patch --]
[-- Type: text/plain, Size: 2469 bytes --]
The idle post_schedule hook is just a vile waste of time, fix it proper.
Cc: alex.shi@linaro.org
Cc: mingo@kernel.org
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Tested-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140117140939.GH11314@laptop.programming.kicks-ass.net
---
kernel/sched/fair.c | 5 +++--
kernel/sched/idle_task.c | 21 ++++++---------------
2 files changed, 9 insertions(+), 17 deletions(-)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2416,7 +2416,8 @@ void idle_exit_fair(struct rq *this_rq)
update_rq_runnable_avg(this_rq, 0);
}
-#else
+#else /* CONFIG_SMP */
+
static inline void update_entity_load_avg(struct sched_entity *se,
int update_cfs_rq) {}
static inline void update_rq_runnable_avg(struct rq *rq, int runnable) {}
@@ -2428,7 +2429,7 @@ static inline void dequeue_entity_load_a
int sleep) {}
static inline void update_cfs_rq_blocked_load(struct cfs_rq *cfs_rq,
int force_update) {}
-#endif
+#endif /* CONFIG_SMP */
static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
--- a/kernel/sched/idle_task.c
+++ b/kernel/sched/idle_task.c
@@ -13,18 +13,8 @@ select_task_rq_idle(struct task_struct *
{
return task_cpu(p); /* IDLE tasks as never migrated */
}
-
-static void pre_schedule_idle(struct rq *rq, struct task_struct *prev)
-{
- idle_exit_fair(rq);
- rq_last_tick_reset(rq);
-}
-
-static void post_schedule_idle(struct rq *rq)
-{
- idle_enter_fair(rq);
-}
#endif /* CONFIG_SMP */
+
/*
* Idle tasks are unconditionally rescheduled:
*/
@@ -37,8 +27,7 @@ static struct task_struct *pick_next_tas
{
schedstat_inc(rq, sched_goidle);
#ifdef CONFIG_SMP
- /* Trigger the post schedule to do an idle_enter for CFS */
- rq->post_schedule = 1;
+ idle_enter_fair(rq);
#endif
return rq->idle;
}
@@ -58,6 +47,10 @@ dequeue_task_idle(struct rq *rq, struct
static void put_prev_task_idle(struct rq *rq, struct task_struct *prev)
{
+#ifdef CONFIG_SMP
+ idle_exit_fair(rq);
+ rq_last_tick_reset(rq);
+#endif
}
static void task_tick_idle(struct rq *rq, struct task_struct *curr, int queued)
@@ -101,8 +94,6 @@ const struct sched_class idle_sched_clas
#ifdef CONFIG_SMP
.select_task_rq = select_task_rq_idle,
- .pre_schedule = pre_schedule_idle,
- .post_schedule = post_schedule_idle,
#endif
.set_curr_task = set_curr_task_idle,
next prev parent reply other threads:[~2014-01-21 11:29 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-21 11:17 [PATCH 0/9] Various sched patches Peter Zijlstra
2014-01-21 11:17 ` [PATCH 1/9] sched: Remove cpu parameter for idle_balance() Peter Zijlstra
2014-01-21 11:17 ` [PATCH 2/9] sched: Fix race in idle_balance() Peter Zijlstra
2014-01-21 11:17 ` [PATCH 3/9] sched: Move idle_stamp up to the core Peter Zijlstra
2014-01-23 12:58 ` Peter Zijlstra
2014-01-23 14:39 ` Daniel Lezcano
2014-01-23 15:23 ` Peter Zijlstra
2014-01-21 11:17 ` Peter Zijlstra [this message]
2014-01-21 17:27 ` [PATCH 4/9] sched: Clean up idle task SMP logic Vincent Guittot
2014-01-23 11:37 ` Peter Zijlstra
2014-01-23 14:52 ` Vincent Guittot
2014-01-21 11:17 ` [PATCH 5/9] sched/fair: Track cgroup depth Peter Zijlstra
2014-01-21 11:18 ` [PATCH 6/9] sched: Push put_prev_task() into pick_next_task() Peter Zijlstra
2014-01-21 21:46 ` bsegall
2014-01-21 11:18 ` [PATCH 7/9] sched/fair: Clean up __clear_buddies_* Peter Zijlstra
2014-01-21 11:18 ` [PATCH 8/9] sched/fair: Optimize cgroup pick_next_task_fair Peter Zijlstra
2014-01-21 19:24 ` bsegall
2014-01-21 19:37 ` Peter Zijlstra
2014-01-21 20:03 ` bsegall
2014-01-21 20:43 ` Peter Zijlstra
2014-01-21 21:43 ` bsegall
2014-01-22 18:06 ` Peter Zijlstra
2014-01-21 11:18 ` [PATCH 9/9] sched: Use idle task shortcut Peter Zijlstra
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