On Sun, Mar 08, 2026 at 08:30:47PM -0700, JP Kobryn (Meta) wrote: > On 3/8/26 12:24 PM, Usama Arif wrote: > > On Fri, 6 Mar 2026 20:55:20 -0800 "JP Kobryn (Meta)" <[email protected]> > > wrote: > [...] > >> +static void mpol_count_numa_alloc(struct mempolicy *pol, int intended_nid, > >> + struct page *page, unsigned int order) > >> +{ > >> + int actual_nid = page_to_nid(page); > >> + long nr_pages = 1L << order; > >> + enum node_stat_item hit_idx; > >> + struct mem_cgroup *memcg; > >> + struct lruvec *lruvec; > >> + bool is_hit; > >> + > >> + if (!root_mem_cgroup || mem_cgroup_disabled()) > >> + return; > > > > Hello JP! > > > > The stats are exposed via /proc/vmstat and are guarded by CONFIG_NUMA, not > > CONFIG_MEMCG. Early returning overhere would make it inaccuate. Does > > it make sense to use mod_node_page_state if memcg is not available, > > so that these global counters work regardless of cgroup configuration. > > > > Good call. I can instead do: > > if (!mem_cgroup_disabled() && root_mem_cgroup) { > struct mem_cgroup *memcg; > struct lruvec *lruvec; > /* use lruvec for updating stats */ > } else { > /* use node for updating stats */ > } > > This should also take care of the bot warning on mem_cgroup_from_task() > not being available.
mem_cgroup_lruvec() and mod_lruvec_state() already do the right thing for !CONFIG_MEMCG. Add a dummy for mem_cgroup_from_task() and you can do a single, shared sequence for both configs.
