Re: [PATCH] mm: Stop kswapd early when nothing's waiting for it to free pages

[Shakeel Butt]

On Tue, Feb 25, 2020 at 1:10 AM Michal Hocko <mhocko@xxxxxxxxxx> wrote:
>
[snip]
>
> The proper fix should, however, check the amount of reclaimable pages
> and back off if they cannot meet the target IMO. We cannot rely on the
> general reclaimability here because that could really be thrashing.
>

"check the amount of reclaimable pages" vs "cannot rely on the general
reclaimability"? Can you clarify?

BTW we are seeing a similar situation in our production environment.
We have swappiness=0, no swap from kswapd (because we don't swapout on
pressure, only on cold age) and too few file pages, the kswapd goes
crazy on shrink_slab and spends 100% cpu on it.

Shakeel