Re: [PATCH v2 6/8] selftests/mm: fix faulting-in code in pagemap_ioctl test

David Hildenbrand (Red Hat)
2026-01-19T11:09:12Z

On 1/7/26 17:48, Kevin Brodsky wrote:
> One of the pagemap_ioctl tests attempts to fault in pages by
> memcpy()'ing them to an unused buffer. This probably worked
> originally, but since commit 46036188ea1f ("selftests/mm: build with
> -O2") the compiler is free to optimise away that unused buffer and
> the memcpy() with it. As a result there might not be any resident
> page in the mapping and the test may fail.

Yes, I assume so. Using FORCE_READ() etc is the way to go.

Should we add

Fixes: 46036188ea1f ("selftests/mm: build with -O2")

?

Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>

--
Cheers

David