Re: [PATCH RFC 00/19] mm: Add __GFP_UNMAPPED

[Vlastimil Babka (SUSE)]

On 2/25/26 17:34, Brendan Jackman wrote:
> .:: What? Why?
> .:: Why [RFC]?
> 
> I really wanted to stop sending RFC and start sending PATCHes but
> getting this series out has taken months longer than I expected, so it's
> time to get something on the list. The known issues here are:
> 
> 1. __GFP_UNMAPPED isn't useful yet until guest_memfd unmapping support
>    [0] gets merged.
> 
> 2. Apparently while implementing the mm-local region, I totally forgot
>    that KPTI existed on 32-bit systems. I expect the 0-day bot to fire a
>    failure on that patch.

I don't think you mentioned (at least in the cover letter) the mm resistance
to add new gfp flags due to number of them being uncomfortably close to 32
already. But I see you've put the new one behind a config. Together with
point 2 I wonder if this is where we can start making some flags and
associated functionality 64-bit only and change gfp_t to unsigned long?