On 12/7/2021 10:27 AM, 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> 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: osalvador <osalvador@xxxxxxx> Cc: Shakeel Butt <shakeelb@xxxxxxxxxx> Cc: Hasan Al Maruf <hasanalmaruf@xxxxxx> Cc: linux-kernel@xxxxxxxxxxxxxxx Cc: linux-mm@xxxxxxxxx ---
LGTM. Please feel free to add: Tested-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
