The following commit has been merged into the sched/psi branch of tip: Commit-ID: e2ad8ab04c5cdfc8dc2f382c45d248ab01dee991 Gitweb: https://git.kernel.org/tip/e2ad8ab04c5cdfc8dc2f382c45d248ab01dee991 Author: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx> AuthorDate: Fri, 26 Aug 2022 00:41:04 +08:00 Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx> CommitterDate: Fri, 09 Sep 2022 11:08:31 +02:00 sched/psi: Save percpu memory when !psi_cgroups_enabled 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> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20220825164111.29534-4-zhouchengming@xxxxxxxxxxxxx --- 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 39463dc..77d53c0 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -201,6 +201,7 @@ void __init psi_init(void) { if (!psi_enable) { static_branch_enable(&psi_disabled); + static_branch_disable(&psi_cgroups_enabled); return; } @@ -950,7 +951,7 @@ 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 = kzalloc(sizeof(struct psi_group), GFP_KERNEL); @@ -968,7 +969,7 @@ 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); @@ -996,7 +997,7 @@ 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/.