From: Jan Kara <jack@xxxxxxx> Subject: mm/migrate.c: cleanup expected_page_refs() Andrea has noted that page migration code propagates page_mapping(page) through the whole migration stack down to migrate_page() function so it seems stupid to then use page_mapping(page) in expected_page_refs() instead of passed down 'mapping' argument. I agree so let's make expected_page_refs() more in line with the rest of the migration stack. Link: http://lkml.kernel.org/r/20190207112314.24872-1-jack@xxxxxxx Signed-off-by: Jan Kara <jack@xxxxxxx> Suggested-by: Andrea Arcangeli <aarcange@xxxxxxxxxx> Reviewed-by: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/migrate.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/mm/migrate.c~mm-cleanup-expected_page_refs +++ a/mm/migrate.c @@ -374,7 +374,7 @@ unlock: } #endif -static int expected_page_refs(struct page *page) +static int expected_page_refs(struct address_space *mapping, struct page *page) { int expected_count = 1; @@ -384,7 +384,7 @@ static int expected_page_refs(struct pag */ expected_count += is_device_private_page(page); expected_count += is_device_public_page(page); - if (page_mapping(page)) + if (mapping) expected_count += hpage_nr_pages(page) + page_has_private(page); return expected_count; @@ -405,7 +405,7 @@ int migrate_page_move_mapping(struct add XA_STATE(xas, &mapping->i_pages, page_index(page)); struct zone *oldzone, *newzone; int dirty; - int expected_count = expected_page_refs(page) + extra_count; + int expected_count = expected_page_refs(mapping, page) + extra_count; if (!mapping) { /* Anonymous page without mapping */ @@ -750,7 +750,7 @@ static int __buffer_migrate_page(struct return migrate_page(mapping, newpage, page, mode); /* Check whether page does not have extra refs before we do more work */ - expected_count = expected_page_refs(page); + expected_count = expected_page_refs(mapping, page); if (page_count(page) != expected_count) return -EAGAIN; _
