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From:   Dietmar Eggemann <dietmar.eggemann@arm.com>
To:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@kernel.org>,
        Juri Lelli <juri.lelli@redhat.com>
Cc:     Luca Abeni <luca.abeni@santannapisa.it>,
        Daniel Bristot de Oliveira <bristot@redhat.com>,
        Valentin Schneider <Valentin.Schneider@arm.com>,
        Qais Yousef <Qais.Yousef@arm.com>, linux-kernel@vger.kernel.org
Subject: [PATCH 5/5] sched/deadline: Use return value of SCHED_WARN_ON() in bw accounting
Date:   Fri, 26 Jul 2019 09:27:56 +0100
Message-Id: <20190726082756.5525-6-dietmar.eggemann@arm.com>
In-Reply-To: <20190726082756.5525-1-dietmar.eggemann@arm.com>
References: <20190726082756.5525-1-dietmar.eggemann@arm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

To make the decision whether to set rq or running bw to 0 in underflow
case use the return value of SCHED_WARN_ON() rather than an extra if
condition.

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
---
 kernel/sched/deadline.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index a9cb52ceb761..66c594b5507e 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -95,8 +95,7 @@ void __sub_running_bw(u64 dl_bw, struct dl_rq *dl_rq)
 
 	lockdep_assert_held(&(rq_of_dl_rq(dl_rq))->lock);
 	dl_rq->running_bw -= dl_bw;
-	SCHED_WARN_ON(dl_rq->running_bw > old); /* underflow */
-	if (dl_rq->running_bw > old)
+	if (SCHED_WARN_ON(dl_rq->running_bw > old)) /* underflow */
 		dl_rq->running_bw = 0;
 	/* kick cpufreq (see the comment in kernel/sched/sched.h). */
 	cpufreq_update_util(rq_of_dl_rq(dl_rq), 0);
@@ -119,8 +118,7 @@ void __sub_rq_bw(u64 dl_bw, struct dl_rq *dl_rq)
 
 	lockdep_assert_held(&(rq_of_dl_rq(dl_rq))->lock);
 	dl_rq->this_bw -= dl_bw;
-	SCHED_WARN_ON(dl_rq->this_bw > old); /* underflow */
-	if (dl_rq->this_bw > old)
+	if (SCHED_WARN_ON(dl_rq->this_bw > old)) /* underflow */
 		dl_rq->this_bw = 0;
 	SCHED_WARN_ON(dl_rq->running_bw > dl_rq->this_bw);
 }
-- 
2.17.1