On 2/18/26 23:26, JP Kobryn (Meta) wrote: > From: JP Kobryn <[email protected]> > > There are situations where reclaim kicks in on a system with free memory. > One possible cause is a NUMA imbalance scenario where one or more nodes are > under pressure. It would help if we could easily identify such nodes. > > Move the pgscan, pgsteal, and pgrefill counters from vm_event_item to > node_stat_item to provide per-node reclaim visibility. With these counters > as node stats, the values are now displayed in the per-node section of > /proc/zoneinfo, which allows for quick identification of the affected > nodes. > > /proc/vmstat continues to report the same counters, aggregated across all > nodes. But the ordering of these items within the readout changes as they > move from the vm events section to the node stats section. > > Memcg accounting of these counters is preserved. The relocated counters > remain visible in memory.stat alongside the existing aggregate pgscan and > pgsteal counters. > > However, this change affects how the global counters are accumulated. > Previously, the global event count update was gated on !cgroup_reclaim(), > excluding memcg-based reclaim from /proc/vmstat. Now that > mod_lruvec_state() is being used to update the counters, the global > counters will include all reclaim. This is consistent with how pgdemote > counters are already tracked. > > Finally, the virtio_balloon driver is updated to use > global_node_page_state() to fetch the counters, as they are no longer > accessible through the vm_events array. > > Signed-off-by: JP Kobryn <[email protected]> > Suggested-by: Johannes Weiner <[email protected]> > Acked-by: Michael S. Tsirkin <[email protected]>
Reviewed-by: Vlastimil Babka (SUSE) <[email protected]>
