From: Peter Zijlstra <peterz@infradead.org>
To: mingo@kernel.org, vincent.guittot@linaro.org,
dietmar.eggemann@arm.com, juri.lelli@redhat.com,
rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de
Cc: linux-kernel@vger.kernel.org, qperret@google.com,
valentin.schneider@arm.com, qais.yousef@arm.com,
ktkhai@virtuozzo.com, peterz@infradead.org
Subject: [PATCH 3/7] sched: Make pick_next_task_idle() more consistent
Date: Fri, 08 Nov 2019 14:15:56 +0100 [thread overview]
Message-ID: <20191108131909.545730862@infradead.org> (raw)
In-Reply-To: 20191108131553.027892369@infradead.org
Only pick_next_task_fair() needs the @prev and @rf argument; these are
required to implement the cpu-cgroup optimization. None of the other
pick_next_task() methods need this. Make pick_next_task_idle() more
consistent.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
kernel/sched/core.c | 6 ++++--
kernel/sched/idle.c | 3 +--
2 files changed, 5 insertions(+), 4 deletions(-)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3922,8 +3922,10 @@ pick_next_task(struct rq *rq, struct tas
goto restart;
/* Assumes fair_sched_class->next == idle_sched_class */
- if (unlikely(!p))
- p = idle_sched_class.pick_next_task(rq, prev, rf);
+ if (unlikely(!p)) {
+ put_prev_task(rq, prev);
+ p = idle_sched_class.pick_next_task(rq, NULL, NULL);
+ }
return p;
}
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -390,8 +390,7 @@ pick_next_task_idle(struct rq *rq, struc
{
struct task_struct *next = rq->idle;
- if (prev)
- put_prev_task(rq, prev);
+ WARN_ON_ONCE(prev || rf);
set_next_task_idle(rq, next);
next prev parent reply other threads:[~2019-11-08 13:21 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-08 13:15 [PATCH 0/7] scheduler patches Peter Zijlstra
2019-11-08 13:15 ` [PATCH 1/7] sched: Fix pick_next_task() vs change pattern race Peter Zijlstra
2019-11-08 14:28 ` Quentin Perret
2019-11-08 16:05 ` Valentin Schneider
2019-11-08 20:49 ` Peter Zijlstra
2019-11-08 17:03 ` Qais Yousef
2019-11-08 13:15 ` [PATCH 2/7] sched/fair: Better document newidle_balance() Peter Zijlstra
2019-11-11 9:32 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2019-11-08 13:15 ` Peter Zijlstra [this message]
2019-11-11 9:32 ` [tip: sched/core] sched/core: Make pick_next_task_idle() more consistent tip-bot2 for Peter Zijlstra
2019-11-08 13:15 ` [PATCH 4/7] sched: Optimize pick_next_task() Peter Zijlstra
2019-11-08 14:33 ` Quentin Perret
2019-11-08 16:46 ` Vincent Guittot
2019-11-08 20:46 ` Peter Zijlstra
2019-11-11 9:32 ` [tip: sched/core] sched/core: " tip-bot2 for Peter Zijlstra
2019-11-08 13:15 ` [PATCH 5/7] sched: Simplify sched_class::pick_next_task() Peter Zijlstra
2019-11-11 9:32 ` [tip: sched/core] sched/core: " tip-bot2 for Peter Zijlstra
2019-11-08 13:15 ` [PATCH 6/7] sched/fair: Use mul_u32_u32() Peter Zijlstra
2019-11-11 9:32 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2019-11-08 13:16 ` [PATCH 7/7] sched: Further clarify sched_class::set_next_task() Peter Zijlstra
2019-11-11 9:32 ` [tip: sched/core] sched/core: " tip-bot2 for Peter Zijlstra
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