Re: [PATCH v4 1/5] cgroup: move rstat base stat objects into their own struct

[Yosry Ahmed <yosry.ahmed@linux.dev>]

On Thu, Apr 03, 2025 at 06:10:46PM -0700, JP Kobryn wrote:
> This non-functional change serves as preparation for moving to
> subsystem-based rstat trees. The base stats are not an actual subsystem,
> but in future commits they will have exclusive rstat trees just as other
> subsystems will.
> 
> Moving the base stat objects into a new struct allows the cgroup_rstat_cpu
> struct to become more compact since it now only contains the minimum amount
> of pointers needed for rstat participation. Subsystems will (in future
> commits) make use of the compact cgroup_rstat_cpu struct while avoiding the
> memory overhead of the base stat objects which they will not use.
> 
> An instance of the new struct cgroup_rstat_base_cpu was placed on the
> cgroup struct so it can retain ownership of these base stats common to all
> cgroups. A helper function was added for looking up the cpu-specific base
> stats of a given cgroup. Finally, initialization and variable names were
> adjusted where applicable.
> 
> Signed-off-by: JP Kobryn <inwardvessel@gmail.com>

Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>