From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: mm/shmem: use pagevec_lookup in shmem_unlock_mapping The comment shows that the reason for using find_get_entries() is now stale; find_get_pages() will not return 0 if it hits a consecutive run of swap entries, and I don't believe it has since 2011. pagevec_lookup() is a simpler function to use than find_get_pages(), so use it instead. Link: https://lkml.kernel.org/r/20201112212641.27837-3-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Reviewed-by: Jan Kara <jack@xxxxxxx> Reviewed-by: William Kucharski <william.kucharski@xxxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Cc: Dave Chinner <dchinner@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/shmem.c | 11 +---------- 1 file changed, 1 insertion(+), 10 deletions(-) --- a/mm/shmem.c~mm-shmem-use-pagevec_lookup-in-shmem_unlock_mapping +++ a/mm/shmem.c @@ -842,7 +842,6 @@ unsigned long shmem_swap_usage(struct vm void shmem_unlock_mapping(struct address_space *mapping) { struct pagevec pvec; - pgoff_t indices[PAGEVEC_SIZE]; pgoff_t index = 0; pagevec_init(&pvec); @@ -850,16 +849,8 @@ void shmem_unlock_mapping(struct address * Minor point, but we might as well stop if someone else SHM_LOCKs it. */ while (!mapping_unevictable(mapping)) { - /* - * Avoid pagevec_lookup(): find_get_pages() returns 0 as if it - * has finished, if it hits a row of PAGEVEC_SIZE swap entries. - */ - pvec.nr = find_get_entries(mapping, index, - PAGEVEC_SIZE, pvec.pages, indices); - if (!pvec.nr) + if (!pagevec_lookup(&pvec, mapping, &index)) break; - index = indices[pvec.nr - 1] + 1; - pagevec_remove_exceptionals(&pvec); check_move_unevictable_pages(&pvec); pagevec_release(&pvec); cond_resched(); _
