[PATCH v2 06/10] sched/psi: save percpu memory when !psi_cgroups_enabled
From: Chengming Zhou
Date: Mon Aug 08 2022 - 07:05:28 EST
We won't use cgroup psi_group when !psi_cgroups_enabled, so don't
bother to alloc percpu memory and init for it.
Also don't need to migrate task PSI stats between cgroups in
cgroup_move_task().
Signed-off-by: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
---
kernel/sched/psi.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index 974471f212a3..595a6c8230b7 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -205,6 +205,7 @@ void __init psi_init(void)
{
if (!psi_enable) {
static_branch_enable(&psi_disabled);
+ static_branch_disable(&psi_cgroups_enabled);
return;
}
@@ -952,7 +953,7 @@ void psi_memstall_leave(unsigned long *flags)
#ifdef CONFIG_CGROUPS
int psi_cgroup_alloc(struct cgroup *cgroup)
{
- if (static_branch_likely(&psi_disabled))
+ if (!static_branch_likely(&psi_cgroups_enabled))
return 0;
cgroup->psi.pcpu = alloc_percpu(struct psi_group_cpu);
@@ -964,7 +965,7 @@ int psi_cgroup_alloc(struct cgroup *cgroup)
void psi_cgroup_free(struct cgroup *cgroup)
{
- if (static_branch_likely(&psi_disabled))
+ if (!static_branch_likely(&psi_cgroups_enabled))
return;
cancel_delayed_work_sync(&cgroup->psi.avgs_work);
@@ -991,7 +992,7 @@ void cgroup_move_task(struct task_struct *task, struct css_set *to)
struct rq_flags rf;
struct rq *rq;
- if (static_branch_likely(&psi_disabled)) {
+ if (!static_branch_likely(&psi_cgroups_enabled)) {
/*
* Lame to do this here, but the scheduler cannot be locked
* from the outside, so we move cgroups from inside sched/.
--
2.36.1