Re: [PATCH] mm, swap: Make VMA based swap readahead configurable

From: Michal Hocko
Date: Wed Sep 27 2017 - 09:50:41 EST


On Wed 27-09-17 22:41:17, Minchan Kim wrote:
> On Wed, Sep 27, 2017 at 03:22:41PM +0200, Michal Hocko wrote:
[...]
> > simply cannot disable swap readahead when page-cluster is 0?
>
> That's was what I want really but Huang want to use two readahead
> algorithms in parallel so he wanted to keep two separated disable
> knobs.

If it breaks existing and documented behavior then it is a clear
regression and it should be fixed. I do not see why this should be
disputable at all.

Working around an issue with a config option sounds like the wrong way
to go because those who cannot do that unconditionally would still see a
regression.
--
Michal Hocko
SUSE Labs