Re: [PATCH v3 0/4] make vmalloc gfp flags usage more apparent

Christoph Hellwig
2025-11-21T07:29:50Z

On Wed, Nov 19, 2025 at 10:55:21AM -0800, Vishal Moola (Oracle) wrote:
> > Unexpected gfp: 0x1000000 (__GFP_NOLOCKDEP). Fixing up to gfp: 0x2dc0 (GFP_KERNEL|__GFP_ZERO|__GFP_NOWARN). Fix your code!
> >
> > I suspect __GFP_NOLOCKDEP should also be permitted by vmalloc.
>
> As far as I can tell, theres only 1 caller of this.
> Christoph started using vmalloc for this xfs call in commit
> e2874632a621 ("xfs: use vmalloc instead of vm_map_area for buffer backing memory").
>
> Looks like xfs uses the flag to prevent false positives. Do
> we want to continue this? If so, I'll send a patch adding the flag to
> the whitelist.

I'm not a fan of __GFP_NOLOCKDEP, but it is a valid hint for the
allocator, so it should be supported.