From: Kemeng Shi shikemeng@huaweicloud.com
mainline inclusion from mainline-v6.7-rc1 commit 27e0db3c21aaf1422980e64b77956e15b839306f category: cleanup bugzilla: https://gitee.com/openeuler/kernel/issues/IBC4T0
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Patch series "Two minor cleanups to break_down_buddy_pages", v2.
Two minor cleanups to break_down_buddy_pages.
This patch (of 2):
1. We always have target in range started with next_page and full free range started with current_buddy.
2. The last split range size is 1 << low and low should be >= 0, then size >= 1. So page + size != page is always true (because size > 0). As summary, current_page will not equal to target page.
Link: https://lkml.kernel.org/r/20230927103514.98281-1-shikemeng@huaweicloud.com Link: https://lkml.kernel.org/r/20230927103514.98281-2-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi shikemeng@huaweicloud.com Acked-by: Naoya Horiguchi naoya.horiguchi@nec.com Cc: Matthew Wilcox (Oracle) willy@infradead.org Cc: Oscar Salvador osalvador@suse.de Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Liu Shixin liushixin2@huawei.com --- mm/page_alloc.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 36cd38df0614..fb6008b30b48 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6955,10 +6955,8 @@ static void break_down_buddy_pages(struct zone *zone, struct page *page, if (set_page_guard(zone, current_buddy, high, migratetype)) continue;
- if (current_buddy != target) { - add_to_free_list(current_buddy, zone, high, migratetype); - set_buddy_order(current_buddy, high); - } + add_to_free_list(current_buddy, zone, high, migratetype); + set_buddy_order(current_buddy, high); } }