From: Uladzislau Rezki <urezki@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Uladzislau 2 Rezki <uladzislau2.rezki@sonymobile.com>
Subject: [RFC 3/3] sched: ignore task_h_load for CPU_NEWLY_IDLE
Date: Mon, 2 Jan 2017 16:39:48 +0100 [thread overview]
Message-ID: <1483371588-17140-3-git-send-email-urezki@gmail.com> (raw)
In-Reply-To: <1483371588-17140-1-git-send-email-urezki@gmail.com>
From: Uladzislau 2 Rezki <uladzislau2.rezki@sonymobile.com>
A load balancer calculates imbalance factor for particular shed
domain and tries to steal up the prescribed amount of weighted load.
However, a small imbalance factor would sometimes prevent us from
stealing any tasks at all. When a CPU is newly idle, it should
steal first task which passes a migration criteria.
Signed-off-by: Uladzislau 2 Rezki <uladzislau2.rezki@sonymobile.com>
---
kernel/sched/fair.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 9ebcab1..00b63cc 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6534,8 +6534,9 @@ static int detach_tasks(struct lb_env *env)
if (sched_feat(LB_MIN) && load < 16 && !env->sd->nr_balance_failed)
goto next;
- if ((load / 2) > env->imbalance)
- goto next;
+ if (env->idle != CPU_NEWLY_IDLE)
+ if ((load / 2) > env->imbalance)
+ goto next;
detach_task(p, env);
list_add(&p->se.group_node, &env->tasks);
--
2.1.4
prev parent reply other threads:[~2017-01-02 15:40 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-02 15:39 [RFC 1/3] sched: set loop_max after rq lock is taken Uladzislau Rezki
2017-01-02 15:39 ` [RFC 2/3] sched: set number of iterations to h_nr_running Uladzislau Rezki
2017-01-02 15:39 ` Uladzislau Rezki [this message]
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