On Thu, Dec 03, 2020 at 11:25:50AM +0100, Peter Zijlstra wrote: > On Wed, Dec 02, 2020 at 11:40:54AM +0000, Mel Gorman wrote: > > On Wed, Dec 02, 2020 at 04:42:32PM +0800, Huang Ying wrote: > > > Now, NUMA balancing can only optimize the page placement among the > > > NUMA nodes if the default memory policy is used. Because the memory > > > policy specified explicitly should take precedence. But this seems > > > too strict in some situations. For example, on a system with 4 NUMA > > > nodes, if the memory of an application is bound to the node 0 and 1, > > > NUMA balancing can potentially migrate the pages between the node 0 > > > and 1 to reduce cross-node accessing without breaking the explicit > > > memory binding policy. > > > > > > > Ok, I think this part is ok and while the test case is somewhat > > superficial, it at least demonstrated that the NUMA balancing overhead > > did not offset any potential benefit > > > > Acked-by: Mel Gorman <mgorman@xxxxxxx> > > Who do we expect to merge this, me through tip/sched/core or akpm ? I would expect akpm, it's much more on the mm side because it affects the semantics of memory policies. It should also have more mm-orientated review than just mine because it affects user-visible semantics and the ability to detect whether the feature is available or not needs to be treated with care. -- Mel Gorman SUSE Labs
