Re: [PATCH v2 0/2] mm: gup: cleanup gup_fast call chain

[Aristeu Rozanski <aris@ruivo.org>]

On Thu, Aug 27, 2026 at 12:01:17PM +0200, David Hildenbrand (Arm) wrote:
> CI flagged that some test cases fail:
> 
> https://github.com/linux-mm/linux-mm/actions/runs/33031249149/job/98384037627?pr=3620
> 
> ==========================================
> ✗ memory failure test failed:
> # not ok 1 memory_failure.madv_hard.anon
> # not ok 2 memory_failure.madv_hard.clean_pagecache
> # not ok 3 memory_failure.madv_hard.dirty_pagecache
> # not ok 4 memory_failure.madv_soft.anon
> # not ok 5 memory_failure.madv_soft.clean_pagecache
> # not ok 6 memory_failure.madv_soft.dirty_pagecache
> 
> and I can reproduce locally.
> 
> They do use get_user_pages_fast(), so it checks out.
> 
> The following fixes most issues for me (there is still one failure on my machine
> but it reproduces even without your patches, so might be specific to my machine):
> 
> diff --git a/mm/gup.c b/mm/gup.c
> index 9b68242b6b602..a4036c02e2137 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -3010,7 +3010,7 @@ static unsigned long gup_fast_pmd_range(pud_t *pudp, pud_t
> pud,
>                 unsigned long addr, unsigned long end,
>                 unsigned int flags, struct page **pages)
>  {
> -       unsigned long next, nr_pages, chunk_nr_pages;
> +       unsigned long next, nr_pages = 0, chunk_nr_pages;
>         pmd_t *pmdp;
> 
>         pmdp = pmd_offset_lockless(pudp, pud, addr);

oof. You want me to post a v3, followup, or you fixed it already?

-- 
Aristeu