By initializing the root cgroup's psi field to psi_system, we can
consistently obtain the psi information for all cgroups from the struct
cgroup.
Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
---
include/linux/psi.h | 2 +-
kernel/cgroup/cgroup.c | 5 ++++-
2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/include/linux/psi.h b/include/linux/psi.h
index e074587..8f2db51 100644
--- a/include/linux/psi.h
+++ b/include/linux/psi.h
@@ -34,7 +34,7 @@ __poll_t psi_trigger_poll(void **trigger_ptr, struct file *file,
#ifdef CONFIG_CGROUPS
static inline struct psi_group *cgroup_psi(struct cgroup *cgrp)
{
- return cgroup_ino(cgrp) == 1 ? &psi_system : cgrp->psi;
+ return cgrp->psi;
}
int psi_cgroup_alloc(struct cgroup *cgrp);
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 8f3cef1..07c7747 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -164,7 +164,10 @@ struct cgroup_subsys *cgroup_subsys[] = {
static DEFINE_PER_CPU(struct cgroup_rstat_cpu, cgrp_dfl_root_rstat_cpu);
/* the default hierarchy */
-struct cgroup_root cgrp_dfl_root = { .cgrp.rstat_cpu = &cgrp_dfl_root_rstat_cpu };
+struct cgroup_root cgrp_dfl_root = {
+ .cgrp.rstat_cpu = &cgrp_dfl_root_rstat_cpu,
+ .cgrp.psi = &psi_system,
+};
EXPORT_SYMBOL_GPL(cgrp_dfl_root);
/*
--
1.8.3.1
