Re: [PATCH 1/2] bcachefs: do not use PF_MEMALLOC_NORECLAIM

Matthew Wilcox
2024-08-26T19:41:47Z

On Mon, Aug 26, 2024 at 03:39:47PM -0400, Kent Overstreet wrote:
> Given the amount of plumbing required here, it's clear that passing gfp
> flags is the less safe way of doing it, and this really does belong in
> the allocation context.
>
> Failure to pass gfp flags correctly (which we know is something that
> happens today, e.g. vmalloc -> pte allocation) means you're introducing
> a deadlock.

The problem with vmalloc is that the page table allocation _doesn't_
take a GFP parameter.