On Thu, Feb 06, 2020 at 07:37:27PM -0800, John Hubbard wrote: > An upcoming patch requires subtracting a large chunk of refcounts from > a page, and checking what the resulting refcount is. This is a little > different than the usual "check for zero refcount" that many of the > page ref functions already do. However, it is similar to a few other > routines that (like this one) are generally useful for things such as > 1-based refcounting. > > Add page_ref_sub_return(), that subtracts a chunk of refcounts > atomically, and returns an atomic snapshot of the result. > > Reviewed-by: Jan Kara <jack@xxxxxxx> > Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx> Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> -- Kirill A. Shutemov
