[tip: sched/core] sched/fair: Check the SD_ASYM_PACKING flag in sched_use_asym_prio()

From: tip-bot2 for Alex Shi
Date: Wed Feb 28 2024 - 17:00:23 EST


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@xxxxxxxxxx>
AuthorDate: Sat, 10 Feb 2024 19:39:22 +08:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Tested-by: Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx>
Reviewed-by: Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx>
Reviewed-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240210113924.1130448-4-alexs@xxxxxxxxxx
---
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));
}