linux-kernel - [tip: sched/core] sched/fair: Check the SD_ASYM_PACKING flag in sched_use_asym

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Date: Wed, 28 Feb 2024 22:00:05 -0000
From: "tip-bot2 for Alex Shi" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Alex Shi <alexs@...nel.org>, Ingo Molnar <mingo@...nel.org>,
 Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>,
 Vincent Guittot <vincent.guittot@...aro.org>, x86@...nel.org,
 linux-kernel@...r.kernel.org
Subject: [tip: sched/core] sched/fair: Check the SD_ASYM_PACKING flag in
 sched_use_asym_prio()

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

Commit-ID:     fbc449864e0d2ee2c16f3af2d1e9093b9b8d7ad0
Gitweb:        https://git.kernel.org/tip/fbc449864e0d2ee2c16f3af2d1e9093b9b8d7ad0
Author:        Alex Shi <alexs@...nel.org>
AuthorDate:    Sat, 10 Feb 2024 19:39:22 +08:00
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Wed, 28 Feb 2024 15:43:17 +01:00

sched/fair: Check the SD_ASYM_PACKING flag in sched_use_asym_prio()

sched_use_asym_prio() checks whether CPU priorities should be used. It
makes sense to check for the SD_ASYM_PACKING() inside the function.
Since both sched_asym() and sched_group_asym() use sched_use_asym_prio(),
remove the now superfluous checks for the flag in various places.

Signed-off-by: Alex Shi <alexs@...nel.org>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Tested-by: Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>
Reviewed-by: Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>
Reviewed-by: Vincent Guittot <vincent.guittot@...aro.org>
Link: https://lore.kernel.org/r/20240210113924.1130448-4-alexs@kernel.org
---
 kernel/sched/fair.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 475e2ca..39781a6 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9744,6 +9744,9 @@ group_type group_classify(unsigned int imbalance_pct,
  */
 static bool sched_use_asym_prio(struct sched_domain *sd, int cpu)
 {
+	if (!(sd->flags & SD_ASYM_PACKING))
+		return false;
+
 	if (!sched_smt_active())
 		return true;
 
@@ -9937,11 +9940,9 @@ static inline void update_sg_lb_stats(struct lb_env *env,
 	sgs->group_weight = group->group_weight;
 
 	/* Check if dst CPU is idle and preferred to this group */
-	if (!local_group && env->sd->flags & SD_ASYM_PACKING &&
-	    env->idle != CPU_NOT_IDLE && sgs->sum_h_nr_running &&
-	    sched_group_asym(env, sgs, group)) {
+	if (!local_group && env->idle != CPU_NOT_IDLE && sgs->sum_h_nr_running &&
+	    sched_group_asym(env, sgs, group))
 		sgs->group_asym_packing = 1;
-	}
 
 	/* Check for loaded SMT group to be balanced to dst CPU */
 	if (!local_group && smt_balance(env, sgs, group))
@@ -11024,9 +11025,7 @@ static struct rq *find_busiest_queue(struct lb_env *env,
 		 * If balancing between cores, let lower priority CPUs help
 		 * SMT cores with more than one busy sibling.
 		 */
-		if ((env->sd->flags & SD_ASYM_PACKING) &&
-		    sched_asym(env->sd, i, env->dst_cpu) &&
-		    nr_running == 1)
+		if (sched_asym(env->sd, i, env->dst_cpu) && nr_running == 1)
 			continue;
 
 		switch (env->migration_type) {
@@ -11122,8 +11121,7 @@ asym_active_balance(struct lb_env *env)
 	 * the lower priority @env::dst_cpu help it. Do not follow
 	 * CPU priority.
 	 */
-	return env->idle != CPU_NOT_IDLE && (env->sd->flags & SD_ASYM_PACKING) &&
-	       sched_use_asym_prio(env->sd, env->dst_cpu) &&
+	return env->idle != CPU_NOT_IDLE && sched_use_asym_prio(env->sd, env->dst_cpu) &&
 	       (sched_asym_prefer(env->dst_cpu, env->src_cpu) ||
 		!sched_use_asym_prio(env->sd, env->src_cpu));
 }