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@xxxxxxxxxxxx> > Reviewed-by: Christoph Hellwig <hch@xxxxxx> > Reviewed-by: John Hubbard <jhubbard@xxxxxxxxxx> > --- > block/bio.c | 2 ++ > include/linux/mmzone.h | 24 ++++++++++++++++++++++++ > 2 files changed, 26 insertions(+) > Reviewed-by: Chaitanya Kulkarni <kch@xxxxxxxxxx> -ck