linux-kernel - [PATCH v6 17/17] sched/topology: Expand use of SD_DEGENERATE_GROUPS

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Date:   Mon, 17 Aug 2020 12:30:03 +0100
From:   Valentin Schneider <valentin.schneider@....com>
To:     linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org
Cc:     mingo@...nel.org, peterz@...radead.org, vincent.guittot@...aro.org,
        dietmar.eggemann@....com, morten.rasmussen@....com,
        Quentin Perret <qperret@...gle.com>
Subject: [PATCH v6 17/17] sched/topology: Expand use of SD_DEGENERATE_GROUPS_MASK to flags not needing groups

All SD flags requiring 2+ sched_group to have any effect are now decorated
with the SDF_NEEDS_GROUPS metaflag. This means we can now use the bitwise
negation of SD_DEGENERATE_MASK in sd_degenerate() instead of explicitly
using SD_WAKE_AFFINE (IOW the only flag without SDF_NEEDS_GROUPS).

>From now on, any flag without SDF_NEEDS_GROUPS will be correctly accounted
as a flag not requiring 2+ sched_groups.

Signed-off-by: Valentin Schneider <valentin.schneider@....com>
---
 kernel/sched/topology.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 8064f495641b..3bb145ef5abd 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -165,7 +165,7 @@ static int sd_degenerate(struct sched_domain *sd)
 		return 0;
 
 	/* Following flags don't use groups */
-	if (sd->flags & (SD_WAKE_AFFINE))
+	if (sd->flags & ~SD_DEGENERATE_GROUPS_MASK)
 		return 0;
 
 	return 1;
-- 
2.27.0