Re: [PATCH 4.20 71/92] Revert "mm: slowly shrink slabs with a relatively small number of objects"

[Sasha Levin]

On Mon, Feb 18, 2019 at 10:30:44AM -0500, Rik van Riel wrote:
> On Mon, 2019-02-18 at 14:43 +0100, Greg Kroah-Hartman wrote:
> > 4.20-stable review patch.  If anyone has any objections, please let
> > me know.
> >
> > ------------------
> >
> > From: Dave Chinner <dchinner@xxxxxxxxxx>
> >
> > commit a9a238e83fbb0df31c3b9b67003f8f9d1d1b6c96 upstream.
> >
> > This reverts commit 172b06c32b9497 ("mm: slowly shrink slabs with a
> > relatively small number of objects").
>
> This revert will result in the slab caches of dead
> cgroups with a small number of remaining objects never
> getting reclaimed, which can be a memory leak in some
> configurations.

What's the "right" choice though? we get either leaky cgroups or hanging
xfs.

> But hey, that's your tradeoff to make.

I don't think that any decision was made here, the stable tree simply
follows upstream with regards to fixes and bugs such as these: we remain
"bug compatible" with upstream in these scenarios, there was no decision
made to prefer either bug.

--
Thanks,
Sasha