linux-kernel - [PATCH 5/7 v3] sched/fair: reorder newidle_balance pulled

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210212141744.24284-6-vincent.guittot@linaro.org>
Date:   Fri, 12 Feb 2021 15:17:42 +0100
From:   Vincent Guittot <vincent.guittot@...aro.org>
To:     mingo@...hat.com, peterz@...radead.org, juri.lelli@...hat.com,
        dietmar.eggemann@....com, rostedt@...dmis.org, bsegall@...gle.com,
        mgorman@...e.de, bristot@...hat.com, linux-kernel@...r.kernel.org,
        joel@...lfernandes.org, valentin.schneider@....com
Cc:     fweisbec@...il.com, tglx@...utronix.de, qais.yousef@....com,
        Vincent Guittot <vincent.guittot@...aro.org>
Subject: [PATCH 5/7 v3] sched/fair: reorder newidle_balance pulled_task tests

Reorder the tests and skip useless ones when no load balance has been
performed and rq lock has not been released.

Signed-off-by: Vincent Guittot <vincent.guittot@...aro.org>
---
 kernel/sched/fair.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index ac4add026f32..5d285d93e433 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -10584,7 +10584,6 @@ static int newidle_balance(struct rq *this_rq, struct rq_flags *rf)
 	if (curr_cost > this_rq->max_idle_balance_cost)
 		this_rq->max_idle_balance_cost = curr_cost;
 
-out:
 	/*
 	 * While browsing the domains, we released the rq lock, a task could
 	 * have been enqueued in the meantime. Since we're not going idle,
@@ -10593,14 +10592,15 @@ static int newidle_balance(struct rq *this_rq, struct rq_flags *rf)
 	if (this_rq->cfs.h_nr_running && !pulled_task)
 		pulled_task = 1;
 
-	/* Move the next balance forward */
-	if (time_after(this_rq->next_balance, next_balance))
-		this_rq->next_balance = next_balance;
-
 	/* Is there a task of a high priority class? */
 	if (this_rq->nr_running != this_rq->cfs.h_nr_running)
 		pulled_task = -1;
 
+out:
+	/* Move the next balance forward */
+	if (time_after(this_rq->next_balance, next_balance))
+		this_rq->next_balance = next_balance;
+
 	if (pulled_task)
 		this_rq->idle_stamp = 0;
 	else
-- 
2.17.1