Re: [PATCH RFC 5/5] non-mm: discourage the usage of __GFP_NOFAIL and encourage GFP_NOFAIL

Michal Hocko
2024-07-24T13:21:19Z

On Wed 24-07-24 06:13:31, Christoph Hellwig wrote:
> On Wed, Jul 24, 2024 at 11:53:49AM +0200, Vlastimil Babka wrote:
> > GFP_KERNEL_NOFAIL which is GFP_KERNEL | __GFP_NOFAIL
> >
> > And probably also GFP_NOFS_NOFAIL and GFP_NOIO_NOFAIL (sigh).
>
> Let's not add these and force people to use the scope API which
> we're trying to move to. I think we should be able to simply
> have GFP_NOFAIL which includes GFP_KERNEL and no variant.

Scope API is tricky here. Exactly because the scope itself could have
opportunistic GFP_NOWAIT allocations. It just takes a library function
to call from a scope that could become a risk because it doesn't know
about potential scopes it can live in.

--
Michal Hocko
SUSE Labs