linux-kernel - [PATCH 06/16] sched: Disable WAKE_AFFINE for asymmetric configurations

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Message-Id: <1464001138-25063-7-git-send-email-morten.rasmussen@arm.com>
Date:	Mon, 23 May 2016 11:58:48 +0100
From:	Morten Rasmussen <morten.rasmussen@....com>
To:	peterz@...radead.org, mingo@...hat.com
Cc:	dietmar.eggemann@....com, yuyang.du@...el.com,
	vincent.guittot@...aro.org, mgalbraith@...e.de,
	linux-kernel@...r.kernel.org,
	Morten Rasmussen <morten.rasmussen@....com>
Subject: [PATCH 06/16] sched: Disable WAKE_AFFINE for asymmetric configurations

If the system has cpu of different compute capacities (e.g. big.LITTLE)
let affine wakeups be constrained to cpus of the same type.

cc: Ingo Molnar <mingo@...hat.com>
cc: Peter Zijlstra <peterz@...radead.org>

Signed-off-by: Morten Rasmussen <morten.rasmussen@....com>
---
 kernel/sched/core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d9619a3..558ec4a 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6410,6 +6410,9 @@ sd_init(struct sched_domain_topology_level *tl, int cpu)
 		sd->idle_idx = 1;
 	}
 
+	if (sd->flags & SD_ASYM_CPUCAPACITY)
+		sd->flags &= ~SD_WAKE_AFFINE;
+
 	sd->private = &tl->data;
 
 	return sd;
-- 
1.9.1