From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753718AbcD0MB3 (ORCPT ); Wed, 27 Apr 2016 08:01:29 -0400 Received: from mx2.suse.de ([195.135.220.15]:51471 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753072AbcD0MB0 (ORCPT ); Wed, 27 Apr 2016 08:01:26 -0400 From: Vlastimil Babka To: Mel Gorman , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Jesper Dangaard Brouer , Vlastimil Babka Subject: [PATCH 3/3] mm, page_alloc: don't duplicate code in free_pcp_prepare Date: Wed, 27 Apr 2016 14:01:16 +0200 Message-Id: <1461758476-450-3-git-send-email-vbabka@suse.cz> X-Mailer: git-send-email 2.8.1 In-Reply-To: <1461758476-450-1-git-send-email-vbabka@suse.cz> References: <5720A987.7060507@suse.cz> <1461758476-450-1-git-send-email-vbabka@suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The new free_pcp_prepare() function shares a lot of code with free_pages_prepare(), which makes this a maintenance risk when some future patch modifies only one of them. We should be able to achieve the same effect (skipping free_pages_check() from !DEBUG_VM configs) by adding a parameter to free_pages_prepare() and making it inline, so the checks (and the order != 0 parts) are eliminated from the call from free_pcp_prepare(). !DEBUG_VM: bloat-o-meter reports no difference, as my gcc was already inlining free_pages_prepare() and the elimination seems to work as expected DEBUG_VM bloat-o-meter: add/remove: 0/1 grow/shrink: 2/0 up/down: 1035/-778 (257) function old new delta __free_pages_ok 297 1060 +763 free_hot_cold_page 480 752 +272 free_pages_prepare 778 - -778 Here inlining didn't occur before, and added some code, but it's ok for a debug option. Signed-off-by: Vlastimil Babka --- mm/page_alloc.c | 34 ++++++---------------------------- 1 file changed, 6 insertions(+), 28 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 163d08ea43f0..b23f641348ab 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -990,7 +990,8 @@ static int free_tail_pages_check(struct page *head_page, struct page *page) return ret; } -static bool free_pages_prepare(struct page *page, unsigned int order) +static __always_inline bool free_pages_prepare(struct page *page, unsigned int order, + bool check_free) { int bad = 0; @@ -1023,7 +1024,7 @@ static bool free_pages_prepare(struct page *page, unsigned int order) } if (PageAnonHead(page)) page->mapping = NULL; - if (free_pages_check(page)) { + if (check_free && free_pages_check(page)) { bad++; } else { page_cpupid_reset_last(page); @@ -1050,7 +1051,7 @@ static bool free_pages_prepare(struct page *page, unsigned int order) #ifdef CONFIG_DEBUG_VM static inline bool free_pcp_prepare(struct page *page) { - return free_pages_prepare(page, 0); + return free_pages_prepare(page, 0, true); } static inline bool bulkfree_pcp_prepare(struct page *page) @@ -1060,30 +1061,7 @@ static inline bool bulkfree_pcp_prepare(struct page *page) #else static bool free_pcp_prepare(struct page *page) { - VM_BUG_ON_PAGE(PageTail(page), page); - - trace_mm_page_free(page, 0); - kmemcheck_free_shadow(page, 0); - kasan_free_pages(page, 0); - - if (PageAnonHead(page)) - page->mapping = NULL; - - reset_page_owner(page, 0); - - if (!PageHighMem(page)) { - debug_check_no_locks_freed(page_address(page), - PAGE_SIZE); - debug_check_no_obj_freed(page_address(page), - PAGE_SIZE); - } - arch_free_page(page, 0); - kernel_poison_pages(page, 0, 0); - kernel_map_pages(page, 0, 0); - - page_cpupid_reset_last(page); - page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; - return true; + return free_pages_prepare(page, 0, false); } static bool bulkfree_pcp_prepare(struct page *page) @@ -1260,7 +1238,7 @@ static void __free_pages_ok(struct page *page, unsigned int order) int migratetype; unsigned long pfn = page_to_pfn(page); - if (!free_pages_prepare(page, order)) + if (!free_pages_prepare(page, order, true)) return; migratetype = get_pfnblock_migratetype(page, pfn); -- 2.8.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f69.google.com (mail-wm0-f69.google.com [74.125.82.69]) by kanga.kvack.org (Postfix) with ESMTP id 8EEE66B025E for ; Wed, 27 Apr 2016 08:01:39 -0400 (EDT) Received: by mail-wm0-f69.google.com with SMTP id s63so36665514wme.2 for ; Wed, 27 Apr 2016 05:01:39 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id qc8si4074565wjc.37.2016.04.27.05.01.25 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 27 Apr 2016 05:01:26 -0700 (PDT) From: Vlastimil Babka Subject: [PATCH 3/3] mm, page_alloc: don't duplicate code in free_pcp_prepare Date: Wed, 27 Apr 2016 14:01:16 +0200 Message-Id: <1461758476-450-3-git-send-email-vbabka@suse.cz> In-Reply-To: <1461758476-450-1-git-send-email-vbabka@suse.cz> References: <5720A987.7060507@suse.cz> <1461758476-450-1-git-send-email-vbabka@suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Jesper Dangaard Brouer , Vlastimil Babka The new free_pcp_prepare() function shares a lot of code with free_pages_prepare(), which makes this a maintenance risk when some future patch modifies only one of them. We should be able to achieve the same effect (skipping free_pages_check() from !DEBUG_VM configs) by adding a parameter to free_pages_prepare() and making it inline, so the checks (and the order != 0 parts) are eliminated from the call from free_pcp_prepare(). !DEBUG_VM: bloat-o-meter reports no difference, as my gcc was already inlining free_pages_prepare() and the elimination seems to work as expected DEBUG_VM bloat-o-meter: add/remove: 0/1 grow/shrink: 2/0 up/down: 1035/-778 (257) function old new delta __free_pages_ok 297 1060 +763 free_hot_cold_page 480 752 +272 free_pages_prepare 778 - -778 Here inlining didn't occur before, and added some code, but it's ok for a debug option. Signed-off-by: Vlastimil Babka --- mm/page_alloc.c | 34 ++++++---------------------------- 1 file changed, 6 insertions(+), 28 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 163d08ea43f0..b23f641348ab 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -990,7 +990,8 @@ static int free_tail_pages_check(struct page *head_page, struct page *page) return ret; } -static bool free_pages_prepare(struct page *page, unsigned int order) +static __always_inline bool free_pages_prepare(struct page *page, unsigned int order, + bool check_free) { int bad = 0; @@ -1023,7 +1024,7 @@ static bool free_pages_prepare(struct page *page, unsigned int order) } if (PageAnonHead(page)) page->mapping = NULL; - if (free_pages_check(page)) { + if (check_free && free_pages_check(page)) { bad++; } else { page_cpupid_reset_last(page); @@ -1050,7 +1051,7 @@ static bool free_pages_prepare(struct page *page, unsigned int order) #ifdef CONFIG_DEBUG_VM static inline bool free_pcp_prepare(struct page *page) { - return free_pages_prepare(page, 0); + return free_pages_prepare(page, 0, true); } static inline bool bulkfree_pcp_prepare(struct page *page) @@ -1060,30 +1061,7 @@ static inline bool bulkfree_pcp_prepare(struct page *page) #else static bool free_pcp_prepare(struct page *page) { - VM_BUG_ON_PAGE(PageTail(page), page); - - trace_mm_page_free(page, 0); - kmemcheck_free_shadow(page, 0); - kasan_free_pages(page, 0); - - if (PageAnonHead(page)) - page->mapping = NULL; - - reset_page_owner(page, 0); - - if (!PageHighMem(page)) { - debug_check_no_locks_freed(page_address(page), - PAGE_SIZE); - debug_check_no_obj_freed(page_address(page), - PAGE_SIZE); - } - arch_free_page(page, 0); - kernel_poison_pages(page, 0, 0); - kernel_map_pages(page, 0, 0); - - page_cpupid_reset_last(page); - page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; - return true; + return free_pages_prepare(page, 0, false); } static bool bulkfree_pcp_prepare(struct page *page) @@ -1260,7 +1238,7 @@ static void __free_pages_ok(struct page *page, unsigned int order) int migratetype; unsigned long pfn = page_to_pfn(page); - if (!free_pages_prepare(page, order)) + if (!free_pages_prepare(page, order, true)) return; migratetype = get_pfnblock_migratetype(page, pfn); -- 2.8.1 -- 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