Re: [PATCH v3] mm: gup: fix infinite loop within __get_longterm_locked

[David Hildenbrand]

On 22.01.25 02:26, zhaoyang.huang wrote:
> From: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
>
> We can run into an infinite loop in __get_longterm_locked() when
> collect_longterm_unpinnable_folios() finds only folios that are isolated
> from the LRU or were never added to the LRU. This can happen when all
> folios to be pinned are never added to the LRU, for example when
> vm_ops->fault allocated pages using cma_alloc() and never added them to
> the LRU.
>
> Fix it by simply taking a look at the list in the single caller, to see
> if anything was added.
>
> Fixes: 67e139b02d99 ("mm/gup.c: refactor check_and_migrate_movable_pages()")
>
> Reviewed-by: John Hubbard <jhubbard@xxxxxxxxxx>
> Suggested-by: David Hildenbrand <david@xxxxxxxxxx>

^ you should CC all people here. "git send-email" will usually try doing 
that automatically. :)



Acked-by: David Hildenbrand <david@xxxxxxxxxx>

--
Cheers,

David / dhildenb