From: Wanpeng Li <wanpeng.li@linux.intel.com>
To: Ingo Molnar <mingo@redhat.com>, Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@arm.com>,
Kirill Tkhai <ktkhai@parallels.com>,
linux-kernel@vger.kernel.org,
Wanpeng Li <wanpeng.li@linux.intel.com>
Subject: [PATCH v6 5/7] sched/fair: fix idle balance when remaining tasks are all non-CFS tasks
Date: Wed, 26 Nov 2014 08:44:05 +0800 [thread overview]
Message-ID: <1416962647-76792-6-git-send-email-wanpeng.li@linux.intel.com> (raw)
In-Reply-To: <1416962647-76792-1-git-send-email-wanpeng.li@linux.intel.com>
The overload indicator is used for knowing when we can totally avoid load
balancing to a cpu that is about to go idle. We can avoid load balancing
when no cpu has cfs task and both rt and deadline have push/pull mechanism
to do their own balancing.
However, rq->nr_running on behalf of the total number of each class tasks
on the cpu, do idle balance when remaining tasks are all non-CFS tasks does
not make any sense.
This patch fix it by idle balance when there are still other CFS tasks in
the rq's root domain.
Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
---
kernel/sched/fair.c | 2 +-
kernel/sched/sched.h | 3 ++-
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index a1c9267..8b7e131 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6192,7 +6192,7 @@ static inline void update_sg_lb_stats(struct lb_env *env,
sgs->group_load += load;
sgs->sum_nr_running += rq->cfs.h_nr_running;
- if (rq->nr_running > 1)
+ if (rq->nr_running > 1 && rq->cfs.h_nr_running > 0)
*overload = true;
#ifdef CONFIG_NUMA_BALANCING
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 31f1e4d..f7dd978 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1269,7 +1269,8 @@ static inline void add_nr_running(struct rq *rq, unsigned count)
rq->nr_running = prev_nr + count;
- if (prev_nr < 2 && rq->nr_running >= 2) {
+ if (prev_nr < 2 && rq->nr_running >= 2 &&
+ rq->cfs.h_nr_running > 0) {
#ifdef CONFIG_SMP
if (!rq->rd->overload)
rq->rd->overload = true;
--
1.9.1
next prev parent reply other threads:[~2014-11-26 0:46 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-26 0:44 [PATCH v6 0/7] sched: support dl task migration during cpu hotplug and other fixes Wanpeng Li
2014-11-26 0:44 ` [PATCH v6 1/7] sched/deadline: fix start high-res preemption tick for a non-leftmost task Wanpeng Li
2015-02-04 14:34 ` [tip:sched/core] sched/deadline: Fix hrtick " tip-bot for Wanpeng Li
2014-11-26 0:44 ` [PATCH v6 1/7] sched/deadline: fix start high-res preemption tick " Wanpeng Li
2014-11-26 0:34 ` Wanpeng Li
2014-11-26 0:44 ` [PATCH v6 3/7] sched/deadline: fix dl entity is still mark yield after replenishing Wanpeng Li
2015-02-04 14:35 ` [tip:sched/core] sched/deadline: Fix stale yield state tip-bot for Peter Zijlstra
2014-11-26 0:44 ` [PATCH v6 4/7] sched/deadline: reduce overhead if there are no scheduling parameters changed Wanpeng Li
2015-02-04 14:35 ` [tip:sched/core] sched/deadline: Avoid pointless __setscheduler() tip-bot for Wanpeng Li
2014-11-26 0:44 ` Wanpeng Li [this message]
2015-01-19 12:45 ` [PATCH v6 5/7] sched/fair: fix idle balance when remaining tasks are all non-CFS tasks Peter Zijlstra
2015-01-19 17:48 ` Tim Chen
2015-01-19 23:16 ` Wanpeng Li
2015-01-19 23:18 ` Wanpeng Li
2015-01-22 4:05 ` Wanpeng Li
2015-01-22 18:13 ` Tim Chen
2014-11-26 0:44 ` [PATCH v6 6/7] sched: fix start hrtick for short schedule slices on UP Wanpeng Li
2015-02-04 14:35 ` [tip:sched/core] sched: Fix hrtick_start() " tip-bot for Wanpeng Li
2014-11-26 0:44 ` [PATCH v6 7/7] sched/deadline: support dl task migration during cpu hotplug Wanpeng Li
2014-12-18 1:28 ` [PATCH v6 0/7] sched: support dl task migration during cpu hotplug and other fixes Wanpeng Li
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