Re: [PATCH v3 0/4] mm: clarify nofail memory allocation

[Linus Torvalds <torvalds@linux-foundation.org>]

On Thu, 22 Aug 2024 at 17:33, Michal Hocko <mhocko@suse.com> wrote:
>
> Limiting NOFAIL semantic to SLUB and {kv}malloc allocators would make
> some sense then as it could enforce reasonable use more easily I guess.

If by "limit to SLUB" you mean "limit it to the kmalloc() cases that
can be done using the standard *SMALL* buckets, then maybe.

But even then it should probably be only if you don't ask for specific
nodes or other limitations on the allocation.

Because realize that "kmalloc()" and friends will fall back to other
things like __kmalloc_large_node_noprof(), and HELL NO those should
not honor NOFAIL.

And dammit, those kvmalloc() sizes need to be limited too. A number
like 24kB was mentioned. That sounds fine. Maybe even 64kB. But make
it *SMALL*.

And make it clear that it will return NULL if somebody misuses it.

            Linus