Re: [PATCH 5/9] mm: don't avoid high-priority reclaim on unreclaimable nodes

[Hillf Danton]

On March 01, 2017 5:40 AM Johannes Weiner wrote:
> 
> 246e87a93934 ("memcg: fix get_scan_count() for small targets") sought
> to avoid high reclaim priorities for kswapd by forcing it to scan a
> minimum amount of pages when lru_pages >> priority yielded nothing.
> 
> b95a2f2d486d ("mm: vmscan: convert global reclaim to per-memcg LRU
> lists"), due to switching global reclaim to a round-robin scheme over
> all cgroups, had to restrict this forceful behavior to unreclaimable
> zones in order to prevent massive overreclaim with many cgroups.
> 
> The latter patch effectively neutered the behavior completely for all
> but extreme memory pressure. But in those situations we might as well
> drop the reclaimers to lower priority levels. Remove the check.
> 
> Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
> ---
>  mm/vmscan.c | 19 +++++--------------
>  1 file changed, 5 insertions(+), 14 deletions(-)
> 
Acked-by: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx>