From: chenqiwu <chenqiwu@xxxxxxxxxx> Subject: mm/page_alloc: simplify page_is_buddy() for better code readability Simplify page_is_buddy() to reduce the redundant code for better code readability. Link: http://lkml.kernel.org/r/1583853751-5525-1-git-send-email-qiwuchen55@xxxxxxxxx Signed-off-by: chenqiwu <chenqiwu@xxxxxxxxxx> Reviewed-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx> Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx> Acked-by: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 33 +++++++++++++-------------------- 1 file changed, 13 insertions(+), 20 deletions(-) --- a/mm/page_alloc.c~mm-page_alloc-simplify-page_is_buddy-for-better-code-readability +++ a/mm/page_alloc.c @@ -792,32 +792,25 @@ static inline void set_page_order(struct * * For recording page's order, we use page_private(page). */ -static inline int page_is_buddy(struct page *page, struct page *buddy, +static inline bool page_is_buddy(struct page *page, struct page *buddy, unsigned int order) { - if (page_is_guard(buddy) && page_order(buddy) == order) { - if (page_zone_id(page) != page_zone_id(buddy)) - return 0; + if (!page_is_guard(buddy) && !PageBuddy(buddy)) + return false; - VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); + if (page_order(buddy) != order) + return false; - return 1; - } + /* + * zone check is done late to avoid uselessly calculating + * zone/node ids for pages that could never merge. + */ + if (page_zone_id(page) != page_zone_id(buddy)) + return false; - if (PageBuddy(buddy) && page_order(buddy) == order) { - /* - * zone check is done late to avoid uselessly - * calculating zone/node ids for pages that could - * never merge. - */ - if (page_zone_id(page) != page_zone_id(buddy)) - return 0; + VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); - VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy); - - return 1; - } - return 0; + return true; } #ifdef CONFIG_COMPACTION _
