On Wed, 17 Aug 2022 13:57:00 -0700
Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> The quilt patch titled
> Subject: mm: re-allow pinning of zero pfns (again)
> has been removed from the -mm tree. Its filename was
> mm-re-allow-pinning-of-zero-pfns-again.patch
>
> This patch was dropped because it was merged into the mm-hotfixes-stable branch
> of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
>
> ------------------------------------------------------
> From: Alex Williamson <alex.williamson@xxxxxxxxxx>
> Subject: mm: re-allow pinning of zero pfns (again)
> Date: Wed, 10 Aug 2022 10:53:59 -0600
>
> The below referenced commit makes the same error as 1c563432588d ("mm: fix
> is_pinnable_page against a cma page"), re-interpreting the logic to
> exclude pinning of the zero page, which breaks device assignment with
> vfio.
>
> To avoid further subtle mistakes, split the logic into discrete tests.
>
> Link: https://lkml.kernel.org/r/166015037385.760108.16881097713975517242.stgit@omen
> Link: https://lore.kernel.org/all/165490039431.944052.12458624139225785964.stgit@omen
> Fixes: f25cbb7a95a2 ("mm: add zone device coherent type memory support")
> Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
> Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
> Suggested-by: Felix Kuehling <felix.kuehling@xxxxxxx>
> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
> Cc: Alex Sierra <alex.sierra@xxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Alistair Popple <apopple@xxxxxxxxxx>
> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> ---
>
> include/linux/mm.h | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> --- a/include/linux/mm.h~mm-re-allow-pinning-of-zero-pfns-again
> +++ a/include/linux/mm.h
> @@ -1544,9 +1544,8 @@ static inline bool is_longterm_pinnable_
> if (mt == MIGRATE_CMA || mt == MIGRATE_ISOLATE)
> return false;
> #endif
> - return !(is_device_coherent_page(page) ||
> - is_zone_movable_page(page) ||
> - is_zero_pfn(page_to_pfn(page)));
> + return !(is_device_coherent_page(page) || is_zone_movable_page(page)) ||
> + is_zero_pfn(page_to_pfn(page));
> }
> #else
> static inline bool is_longterm_pinnable_page(struct page *page)
Something is off here, this is the v1 patch with the v2 commit log,
including link to the v2 posting. Thanks,
Alex
