Re: [linux-next:master] [mm] 0fa2857d23: WARNING:at_mm/page_alloc.c:#__alloc_pages_noprof

[Yosry Ahmed]

On Mon, Jun 24, 2024 at 1:49 AM kernel test robot <oliver.sang@xxxxxxxxx> wrote:
>
>
>
> Hello,
>
> kernel test robot noticed "WARNING:at_mm/page_alloc.c:#__alloc_pages_noprof" on:
>
> commit: 0fa2857d23aa170e5e28d13c467b303b0065aad8 ("mm: store zero pages to be swapped out in a bitmap")
> https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master

This is coming from WARN_ON_ONCE_GFP(order > MAX_PAGE_ORDER, gfp), and
is triggered by the new bitmap_zalloc() call in the swapon path. For a
sufficiently large swapfile, bitmap_zalloc() (which uses kmalloc()
under the hood) cannot be used to allocate the bitmap.

Usama, I think we want to use a variant of kvmalloc() here.