On Fri, Feb 05, 2021 at 08:41:24PM +0000, Joao Martins wrote: > Add an helper that iterates over head pages in a list of pages. It > essentially counts the tails until the next page to process has a > different head that the current. This is going to be used by > unpin_user_pages() family of functions, to batch the head page refcount > updates once for all passed consecutive tail pages. > > Suggested-by: Jason Gunthorpe <jgg@xxxxxxxxxx> > Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx> > Reviewed-by: John Hubbard <jhubbard@xxxxxxxxxx> > --- > mm/gup.c | 26 ++++++++++++++++++++++++++ > 1 file changed, 26 insertions(+) Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx> This can be used for check_and_migrate_cma_pages() too (there is a series around to change this logic though, not sure if it is landed yet) Jason
