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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 6/7] sched/fair: Use mul_u32_u32()
Date: Fri, 08 Nov 2019 14:15:59 +0100
Message-ID: <20191108131909.717931380@infradead.org> (raw)
In-Reply-To: <20191108131553.027892369@infradead.org>

While reading the code I encountered another site where we should be
using mul_u32_u32() because GCC just won't take a hint.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 kernel/sched/fair.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -229,8 +229,7 @@ static u64 __calc_delta(u64 delta_exec,
 		}
 	}
 
-	/* hint to use a 32x32->64 mul */
-	fact = (u64)(u32)fact * lw->inv_weight;
+	fact = mul_u32_u32(fact, lw->inv_weight);
 
 	while (fact >> 32) {
 		fact >>= 1;



  parent reply index

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 ` [PATCH 3/7] sched: Make pick_next_task_idle() more consistent Peter Zijlstra
2019-11-11  9:32   ` [tip: sched/core] sched/core: " 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 ` Peter Zijlstra [this message]
2019-11-11  9:32   ` [tip: sched/core] sched/fair: Use mul_u32_u32() 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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