On Wed 26-02-25 11:52:41, Michal Hocko wrote: > On Wed 26-02-25 18:00:26, Baoquan He wrote: > > On 02/26/25 at 07:54am, Michal Hocko wrote: > [...] > > > In any case 96a5c186efff seems incorrect because it assumes that the > > > protection has anything to do with how higher zone is populated while > > > the protection fundamentaly protects lower zone from higher zones > > > allocation. Those allocations are independent on the actual memory in > > > that zone. > > > > The protection value was introduced in non-NUMA time, and later adapted > > to NUMA system. While it still only reflects each zone with other zones > > within one specific node. We may need take this opportunity to > > reconsider it, e.g in the FALLBACK zonelists case it needs take crossing > > nodes into account. > > Are you suggesting zone fallback list to interleave nodes? I.e. > numa_zonelist_order we used to have in the past and that has been > removed by c9bff3eebc09 ("mm, page_alloc: rip out ZONELIST_ORDER_ZONE"). Btw. has 96a5c186efff tried to fix any actual runtime problem? The changelog doesn't say much about that. -- Michal Hocko SUSE Labs