Re: [PATCH] mm: thp: remove use_zero_page sysfs knob

From: Matthew Wilcox
Date: Sat Jul 21 2018 - 23:52:25 EST


On Fri, Jul 20, 2018 at 02:05:52PM -0700, David Rientjes wrote:
> The huge zero page can be reclaimed under memory pressure and, if it is,
> it is attempted to be allocted again with gfp flags that attempt memory
> compaction that can become expensive. If we are constantly under memory
> pressure, it gets freed and reallocated millions of times always trying to
> compact memory both directly and by kicking kcompactd in the background.
>
> It likely should also be per node.

Have you benchmarked making the non-huge zero page per-node?