linux-kernel - [tip: sched/core] sched/topology: Use prebuilt SD flag degeneration mask

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Date:   Wed, 19 Aug 2020 14:02:46 -0000
From:   "tip-bot2 for Valentin Schneider" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Valentin Schneider <valentin.schneider@....com>,
        Ingo Molnar <mingo@...nel.org>,
        Peter Zijlstra <a.p.zijlstra@...llo.nl>, x86 <x86@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: [tip: sched/core] sched/topology: Use prebuilt SD flag degeneration mask

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     6f349818621dff364fc000909135d0065e9756c9
Gitweb:        https://git.kernel.org/tip/6f349818621dff364fc000909135d0065e9756c9
Author:        Valentin Schneider <valentin.schneider@....com>
AuthorDate:    Mon, 17 Aug 2020 12:29:54 +01:00
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Wed, 19 Aug 2020 10:49:48 +02:00

sched/topology: Use prebuilt SD flag degeneration mask

Leverage SD_DEGENERATE_GROUPS_MASK in sd_degenerate() and
sd_parent_degenerate().

Suggested-by: Peter Zijlstra <peterz@...radead.org>
Signed-off-by: Valentin Schneider <valentin.schneider@....com>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Link: https://lore.kernel.org/r/20200817113003.20802-9-valentin.schneider@arm.com
---
 kernel/sched/topology.c | 20 ++++----------------
 1 file changed, 4 insertions(+), 16 deletions(-)

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index cbdaf08..38e6671 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -160,15 +160,9 @@ static int sd_degenerate(struct sched_domain *sd)
 		return 1;
 
 	/* Following flags need at least 2 groups */
-	if (sd->flags & (SD_BALANCE_NEWIDLE |
-			 SD_BALANCE_FORK |
-			 SD_BALANCE_EXEC |
-			 SD_SHARE_CPUCAPACITY |
-			 SD_ASYM_CPUCAPACITY |
-			 SD_SHARE_PKG_RESOURCES)) {
-		if (sd->groups != sd->groups->next)
-			return 0;
-	}
+	if ((sd->flags & SD_DEGENERATE_GROUPS_MASK) &&
+	    (sd->groups != sd->groups->next))
+		return 0;
 
 	/* Following flags don't use groups */
 	if (sd->flags & (SD_WAKE_AFFINE))
@@ -190,13 +184,7 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
 
 	/* Flags needing groups don't count if only 1 group in parent */
 	if (parent->groups == parent->groups->next) {
-		pflags &= ~(SD_BALANCE_NEWIDLE |
-			    SD_BALANCE_FORK |
-			    SD_BALANCE_EXEC |
-			    SD_ASYM_CPUCAPACITY |
-			    SD_SHARE_CPUCAPACITY |
-			    SD_SHARE_PKG_RESOURCES |
-			    SD_PREFER_SIBLING);
+		pflags &= ~(SD_DEGENERATE_GROUPS_MASK | SD_PREFER_SIBLING);
 		if (nr_node_ids == 1)
 			pflags &= ~SD_SERIALIZE;
 	}