Commit e37deb24 authored by Keisuke Nishimura's avatar Keisuke Nishimura Committed by Zheng Zucheng
Browse files

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

mainline inclusion
from mainline-v6.9-rc1
commit 23d04d8c6b8ec339057264659b7834027f3e6a63
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAE7OO

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=23d04d8c6b8ec339057264659b7834027f3e6a63



--------------------------------

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: 9fe1f127 ("sched/fair: Merge select_idle_core/cpu()")
Signed-off-by: default avatarKeisuke Nishimura <keisuke.nishimura@inria.fr>
Signed-off-by: default avatarJulia Lawall <julia.lawall@inria.fr>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240110131707.437301-2-keisuke.nishimura@inria.fr



Conflicts:
	kernel/sched/fair.c
Signed-off-by: default avatarZheng Zucheng <zhengzucheng@huawei.com>
parent 2d2a1b21

kernel/sched/fair.c

+2 −6
Original line number Diff line number Diff line
@@ -7223,11 +7223,7 @@ 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) {

#ifdef CONFIG_TASK_PLACEMENT_BY_CPU_RANGE

				if (sched_idle_cpu(cpu) && cpumask_test_cpu(cpu, p->select_cpus)) {

#else

				if (sched_idle_cpu(cpu) && cpumask_test_cpu(cpu, p->cpus_ptr)) {

#endif

				if (sched_idle_cpu(cpu) && cpumask_test_cpu(cpu, cpus)) {

					*idle_cpu = cpu;

					break;

				}
@@ -7235,7 +7231,7 @@ 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;

	}