Re: [PATCH 0/2 v2] remove PF_MEMALLOC_NORECLAIM

From: Kent Overstreet
Date: Mon Sep 02 2024 - 05:54:24 EST


On Mon, Sep 02, 2024 at 11:51:48AM GMT, Michal Hocko wrote:
> The previous version has been posted in [1]. Based on the review feedback
> I have sent v2 of patches in the same threat but it seems that the
> review has mostly settled on these patches. There is still an open
> discussion on whether having a NORECLAIM allocator semantic (compare to
> atomic) is worthwhile or how to deal with broken GFP_NOFAIL users but
> those are not really relevant to this particular patchset as it 1)
> doesn't aim to implement either of the two and 2) it aims at spreading
> PF_MEMALLOC_NORECLAIM use while it doesn't have a properly defined
> semantic now that it is not widely used and much harder to fix.
>
> I have collected Reviewed-bys and reposting here. These patches are
> touching bcachefs, VFS and core MM so I am not sure which tree to merge
> this through but I guess going through Andrew makes the most sense.
>
> Changes since v1;
> - compile fixes
> - rather than dropping PF_MEMALLOC_NORECLAIM alone reverted eab0af905bfc
> ("mm: introduce PF_MEMALLOC_NORECLAIM, PF_MEMALLOC_NOWARN") suggested
> by Matthew.

To reiterate:

This is a trainwreck of bad ideas. Nack.