Re: [PATCH V2 2/3] mm: page_alloc: correct high atomic reserve calculations

From: Mel Gorman
Date: Fri Nov 17 2023 - 11:20:04 EST


On Thu, Nov 16, 2023 at 01:52:26PM +0100, Michal Hocko wrote:
> On Thu 16-11-23 09:59:01, Mel Gorman wrote:
> [...]
> > This patch in isolation seems fine with the caveat that such a small
> > system may find the atomic reserves to be borderline useless.
>
> Yes, exactly what I had in mind. Would it make sense to reserve the the
> pageblock only if it really is less than 1% of available memory?

I'd have no objection with the caveat that we need to watch out for new
bugs related to high-order atomic failures. If ths risk is noted in the
changelog and that it's a revert candidate then any bisection should
trivially find it.

--
Mel Gorman
SUSE Labs