Re: [PATCH 01/11] cgroup: move rstat pointers into struct of their own

Shakeel Butt
2025-02-19T01:23:36Z

On Tue, Feb 18, 2025 at 05:05:52PM -0800, Shakeel Butt wrote:
> Thanks JP for awesome work. I am doing a quick first iteration and later
> will do the deep review.
>
> On Mon, Feb 17, 2025 at 07:14:38PM -0800, JP Kobryn wrote:
> > struct cgroup_freezer_state {
> > /* Should the cgroup and its descendants be frozen. */
> > bool freeze;
> > @@ -517,23 +445,9 @@ struct cgroup {
> > struct cgroup *old_dom_cgrp; /* used while enabling threaded */
> >
> > /* per-cpu recursive resource statistics */
> > - struct cgroup_rstat_cpu __percpu *rstat_cpu;
> > + struct cgroup_rstat rstat;
> > struct list_head rstat_css_list;
>
> You might want to place rstat after rstat_css_list just to keep
> (hopefully) on the same cacheline as before other this will put
> rstat_css_list with rstat_flush_next which the current padding is trying
> to avoid. This is just to be safe. Later we might want to reevaluate the
> padding and right cacheline alignments of the fields of struct cgroup.
>

Ah I see later you can removed rstat_css_list as you moved the rstat
state from cgroup to css and you don't need rstat_css_list anymore.