Hello, On Fri, Dec 22, 2023 at 11:30:59AM +0000, Yafang Shao wrote: > 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; > } How have you tested this change? Looking at the code there are other references to psi_system, e.g. to show it under /proc/pressure/* and to exempt it from CPU FULL accounting. I don't see how the above change would be sufficient. Thanks. -- tejun