On 21 Jul 2021, at 2:39, Huang Ying wrote:

> From: Dave Hansen <dave.hansen@linux.intel.com>
>
> Global reclaim aims to reduce the amount of memory used on a given node or
> set of nodes.  Migrating pages to another node serves this purpose.
>
> memcg reclaim is different.  Its goal is to reduce the total memory
> consumption of the entire memcg, across all nodes.  Migration does not
> assist memcg reclaim because it just moves page contents between nodes
> rather than actually reducing memory consumption.
>
> Link: https://lkml.kernel.org/r/20210715055145.195411-9-ying.huang@intel.com
> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
> Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
> Suggested-by: Yang Shi <yang.shi@linux.alibaba.com>
> Reviewed-by: Yang Shi <shy828301@gmail.com>
> Cc: Michal Hocko <mhocko@suse.com>
> Cc: Wei Xu <weixugc@google.com>
> Cc: Oscar Salvador <osalvador@suse.de>
> Cc: Zi Yan <ziy@nvidia.com>
> Cc: David Rientjes <rientjes@google.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Greg Thelen <gthelen@google.com>
> Cc: Keith Busch <kbusch@kernel.org>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
>  mm/vmscan.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)

LGTM. Reviewed-by: Zi Yan <ziy@nvidia.com>.

Should this be folded into Patch 4 when can_demote() is introduced?


—
Best Regards,
Yan, Zi