Re: [PATCH v3 28/30 fix 1/2] mm: memcontrol: fix lruvec_stats->state_local reparenting

[Shakeel Butt]

On Tue, Jan 20, 2026 at 03:19:00PM +0800, Muchun Song wrote:
> 
> 
> >> No reparenting local stats for v2.
> > 
> > It seems that lruvec_stats->state_local (non-hierarchical) needs to be
> > relocated in both v1 and v2.
> 
> Here we might need to elaborate a bit. Specifically, in the function
> `count_shadow_nodes`, the use of `lruvec_page_state_local` to obtain
> LRU and SLAB pages seems to also require these logics to work correctly.
> For SLAB, it appears that the statistics here have already been
> problematic for a while since SLAB pages have been reparented, right?
> 

Thanks a lot, now it is clear and yes it seems like SLAB is problematic
but now I am wondering if it is really worth fixing. For LRU pages, how
about using lruvec_lru_size() defined in vmscan.c. That would at least
keep count_shadow_nodes() working irrespective of LRU reparenting.