On Mon, Feb 21, 2022 at 04:45:29PM +0800, Huang Ying wrote: > If the NUMA balancing isn't used to optimize the page placement among > sockets but only among memory types, the hot pages in the fast memory > node couldn't be migrated (promoted) to anywhere. So it's unnecessary > to scan the pages in the fast memory node via changing their PTE/PMD > mapping to be PROT_NONE. So that the page faults could be avoided > too. > > In the test, if only the memory tiering NUMA balancing mode is enabled, the > number of the NUMA balancing hint faults for the DRAM node is reduced to > almost 0 with the patch. While the benchmark score doesn't change > visibly. > > Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx> > Suggested-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> > Tested-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> > Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> > Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Michal Hocko <mhocko@xxxxxxxx> > Cc: Rik van Riel <riel@xxxxxxxxxxx> > Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Cc: Yang Shi <shy828301@xxxxxxxxx> > Cc: Zi Yan <ziy@xxxxxxxxxx> > Cc: Wei Xu <weixugc@xxxxxxxxxx> > Cc: Oscar Salvador <osalvador@xxxxxxx> > Cc: Shakeel Butt <shakeelb@xxxxxxxxxx> > Cc: zhongjiang-ali <zhongjiang-ali@xxxxxxxxxxxxxxxxx> > Cc: linux-kernel@xxxxxxxxxxxxxxx > Cc: linux-mm@xxxxxxxxx Reviewed-by: Oscar Salvador <osalvador@xxxxxxx> -- Oscar Salvador SUSE Labs
