Hello.
On Mon, Jul 29, 2024 at 10:58:24AM GMT, Xiu Jianfeng <xiujianfeng@xxxxxxxxxxxxxxx> wrote:
> To address this issue, only the cgroups from 'pids_over_limit' to root
> will have their PIDCG_MAX counter increased and event notifications
> generated.
>
For completeness here
Fixes: 385a635cacfe0 ("cgroup/pids: Make event counters hierarchical")
> Signed-off-by: Xiu Jianfeng <xiujianfeng@xxxxxxxxxx>
> ---
> kernel/cgroup/pids.c | 13 ++++---------
> 1 file changed, 4 insertions(+), 9 deletions(-)
> @@ -257,15 +256,11 @@ static void pids_event(struct pids_cgroup *pids_forking,
> cgrp_dfl_root.flags & CGRP_ROOT_PIDS_LOCAL_EVENTS)
> return;
>
> - for (; parent_pids(p); p = parent_pids(p)) {
> - if (p == pids_over_limit) {
> - limit = true;
> - atomic64_inc(&p->events_local[PIDCG_MAX]);
> - cgroup_file_notify(&p->events_local_file);
> - }
> - if (limit)
> - atomic64_inc(&p->events[PIDCG_MAX]);
> + atomic64_inc(&pids_over_limit->events_local[PIDCG_MAX]);
> + cgroup_file_notify(&pids_over_limit->events_local_file);
>
> + for (p = pids_over_limit; parent_pids(p); p = parent_pids(p)) {
> + atomic64_inc(&p->events[PIDCG_MAX]);
> cgroup_file_notify(&p->events_file);
> }
When I look at it applied altogther, there's one extra notification
(heritage of forkfail events), it should be fixed with:
--- a/kernel/cgroup/pids.c
+++ b/kernel/cgroup/pids.c
@@ -251,10 +251,11 @@ static void pids_event(struct pids_cgroup *pids_forking,
pr_cont_cgroup_path(p->css.cgroup);
pr_cont("\n");
}
- cgroup_file_notify(&p->events_local_file);
if (!cgroup_subsys_on_dfl(pids_cgrp_subsys) ||
- cgrp_dfl_root.flags & CGRP_ROOT_PIDS_LOCAL_EVENTS)
+ cgrp_dfl_root.flags & CGRP_ROOT_PIDS_LOCAL_EVENTS) {
+ cgroup_file_notify(&p->events_local_file);
return;
+ }
atomic64_inc(&pids_over_limit->events_local[PIDCG_MAX]);
cgroup_file_notify(&pids_over_limit->events_local_file);
Besides that it makes sense to me.
Thanks,
Michal
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