Re: [PATCH v2 5/7] mm, page_alloc: cache pageset high and batch in struct zone

[Oscar Salvador <osalvador@suse.de>]

On Thu, Oct 08, 2020 at 07:55:02PM +0200, Vlastimil Babka wrote:
> Right, here's updated patch:
> 
> ----8<----
> From 6ab0f03762d122a896349d5e568f75c20875eb42 Mon Sep 17 00:00:00 2001
> From: Vlastimil Babka <vbabka@suse.cz>
> Date: Mon, 7 Sep 2020 14:20:08 +0200
> Subject: [PATCH v2 5/7] mm, page_alloc: cache pageset high and batch in struct
>  zone
> 
> All per-cpu pagesets for a zone use the same high and batch values, that are
> duplicated there just for performance (locality) reasons. This patch adds the
> same variables also to struct zone as a shared copy.
> 
> This will be useful later for making possible to disable pcplists temporarily
> by setting high value to 0, while remembering the values for restoring them
> later. But we can also immediately benefit from not updating pagesets of all
> possible cpus in case the newly recalculated values (after sysctl change or
> memory online/offline) are actually unchanged from the previous ones.
> 
> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
> Acked-by: Michal Hocko <mhocko@suse.com>

LGTM,

Reviewed-by: Oscar Salvador <osalvador@suse.de>

-- 
Oscar Salvador
SUSE L3