From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: mm/swap: optimise get_shadow_from_swap_cache There's no need to get a reference to the page, just load the entry and see if it's a shadow entry. Link: https://lkml.kernel.org/r/20201112212641.27837-4-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Cc: Dave Chinner <dchinner@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Jan Kara <jack@xxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: William Kucharski <william.kucharski@xxxxxxxxxx> Cc: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/swap_state.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) --- a/mm/swap_state.c~mm-swap-optimise-get_shadow_from_swap_cache +++ a/mm/swap_state.c @@ -87,11 +87,9 @@ void *get_shadow_from_swap_cache(swp_ent pgoff_t idx = swp_offset(entry); struct page *page; - page = find_get_entry(address_space, idx); + page = xa_load(&address_space->i_pages, idx); if (xa_is_value(page)) return page; - if (page) - put_page(page); return NULL; } _
