From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f71.google.com (mail-wm0-f71.google.com [74.125.82.71]) by kanga.kvack.org (Postfix) with ESMTP id 11B8C6B0038 for ; Fri, 16 Dec 2016 07:00:28 -0500 (EST) Received: by mail-wm0-f71.google.com with SMTP id y16so7216569wmd.6 for ; Fri, 16 Dec 2016 04:00:28 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id w4si6690730wja.236.2016.12.16.04.00.26 for (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 16 Dec 2016 04:00:26 -0800 (PST) From: Vlastimil Babka Subject: [PATCH v2 2/2] mm, page_alloc: avoid page_to_pfn() when merging buddies Date: Fri, 16 Dec 2016 13:00:09 +0100 Message-Id: <20161216120009.20064-2-vbabka@suse.cz> In-Reply-To: <20161216120009.20064-1-vbabka@suse.cz> References: <20161216120009.20064-1-vbabka@suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Joonsoo Kim , Michal Hocko , Mel Gorman , "Kirill A. Shutemov" , Johannes Weiner , Vlastimil Babka On architectures that allow memory holes, page_is_buddy() has to perform page_to_pfn() to check for the memory hole. After the previous patch, we have the pfn already available in __free_one_page(), which is the only caller of page_is_buddy(), so move the check there and avoid page_to_pfn(). Signed-off-by: Vlastimil Babka Acked-by: Mel Gorman --- mm/page_alloc.c | 10 +++++----- mm/page_isolation.c | 2 +- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 771fc8e18736..f546eeea24d6 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -714,7 +714,7 @@ static inline void rmv_page_order(struct page *page) /* * This function checks whether a page is free && is the buddy * we can do coalesce a page and its buddy if - * (a) the buddy is not in a hole && + * (a) the buddy is not in a hole (check before calling!) && * (b) the buddy is in the buddy system && * (c) a page and its buddy have the same order && * (d) a page and its buddy are in the same zone. @@ -729,9 +729,6 @@ static inline void rmv_page_order(struct page *page) static inline int page_is_buddy(struct page *page, struct page *buddy, unsigned int order) { - if (!pfn_valid_within(page_to_pfn(buddy))) - return 0; - if (page_is_guard(buddy) && page_order(buddy) == order) { if (page_zone_id(page) != page_zone_id(buddy)) return 0; @@ -808,6 +805,9 @@ static inline void __free_one_page(struct page *page, while (order < max_order - 1) { buddy_pfn = __find_buddy_pfn(pfn, order); buddy = page + (buddy_pfn - pfn); + + if (!pfn_valid_within(buddy_pfn)) + goto done_merging; if (!page_is_buddy(page, buddy, order)) goto done_merging; /* @@ -862,7 +862,7 @@ static inline void __free_one_page(struct page *page, * so it's less likely to be used soon and more likely to be merged * as a higher order page */ - if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) { + if ((order < MAX_ORDER-2) && pfn_valid_within(buddy_pfn)) { struct page *higher_page, *higher_buddy; combined_pfn = buddy_pfn & pfn; higher_page = page + (combined_pfn - pfn); diff --git a/mm/page_isolation.c b/mm/page_isolation.c index dadb7e74d7d6..f4e17a57926a 100644 --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -106,7 +106,7 @@ static void unset_migratetype_isolate(struct page *page, unsigned migratetype) buddy_pfn = __find_buddy_pfn(pfn, order); buddy = page + (buddy_pfn - pfn); - if (pfn_valid_within(page_to_pfn(buddy)) && + if (pfn_valid_within(buddy_pfn) && !is_migrate_isolate_page(buddy)) { __isolate_free_page(page, order); isolated_page = true; -- 2.11.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org