Re: [PATCH v11 4/9] block: add check when merging zone device pages

Chaitanya Kulkarni
2022-10-25T01:16:35Z

On 10/21/22 10:41, Logan Gunthorpe wrote:
> Consecutive zone device pages should not be merged into the same sgl
> or bvec segment with other types of pages or if they belong to different
> pgmaps. Otherwise getting the pgmap of a given segment is not possible
> without scanning the entire segment. This helper returns true either if
> both pages are not zone device pages or both pages are zone device
> pages with the same pgmap.
>
> Add a helper to determine if zone device pages are mergeable and use
> this helper in page_is_mergeable().
>
> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: John Hubbard <jhubbard@nvidia.com>
> ---
> block/bio.c | 2 ++
> include/linux/mmzone.h | 24 ++++++++++++++++++++++++
> 2 files changed, 26 insertions(+)
>

Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

-ck