[tip:,sched/core] sched/fair: Take the scheduling domain into account in select_idle_core()

Message ID 170915761064.398.16226994228942102834.tip-bot2@tip-bot2
State New
Headers
Series [tip:,sched/core] sched/fair: Take the scheduling domain into account in select_idle_core() |

Commit Message

tip-bot2 for Thomas Gleixner Feb. 28, 2024, 10 p.m. UTC
  The following commit has been merged into the sched/core branch of tip:

Commit-ID:     23d04d8c6b8ec339057264659b7834027f3e6a63
Gitweb:        https://git.kernel.org/tip/23d04d8c6b8ec339057264659b7834027f3e6a63
Author:        Keisuke Nishimura <keisuke.nishimura@inria.fr>
AuthorDate:    Wed, 10 Jan 2024 14:17:07 +01:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Wed, 28 Feb 2024 15:15:49 +01:00

sched/fair: Take the scheduling domain into account in select_idle_core()

When picking a CPU on task wakeup, select_idle_core() has to take
into account the scheduling domain where the function looks for the CPU.

This is because the "isolcpus" kernel command line option can remove CPUs
from the domain to isolate them from other SMT siblings.

This change replaces the set of CPUs allowed to run the task from
p->cpus_ptr by the intersection of p->cpus_ptr and sched_domain_span(sd)
which is stored in the 'cpus' argument provided by select_idle_cpu().

Fixes: 9fe1f127b913 ("sched/fair: Merge select_idle_core/cpu()")
Signed-off-by: Keisuke Nishimura <keisuke.nishimura@inria.fr>
Signed-off-by: Julia Lawall <julia.lawall@inria.fr>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240110131707.437301-2-keisuke.nishimura@inria.fr
---
 kernel/sched/fair.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
  

Patch

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 005f6d3..352222d 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7289,7 +7289,7 @@  static int select_idle_core(struct task_struct *p, int core, struct cpumask *cpu
 		if (!available_idle_cpu(cpu)) {
 			idle = false;
 			if (*idle_cpu == -1) {
-				if (sched_idle_cpu(cpu) && cpumask_test_cpu(cpu, p->cpus_ptr)) {
+				if (sched_idle_cpu(cpu) && cpumask_test_cpu(cpu, cpus)) {
 					*idle_cpu = cpu;
 					break;
 				}
@@ -7297,7 +7297,7 @@  static int select_idle_core(struct task_struct *p, int core, struct cpumask *cpu
 			}
 			break;
 		}
-		if (*idle_cpu == -1 && cpumask_test_cpu(cpu, p->cpus_ptr))
+		if (*idle_cpu == -1 && cpumask_test_cpu(cpu, cpus))
 			*idle_cpu = cpu;
 	}