Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755552AbbHYNcF (ORCPT ); Tue, 25 Aug 2015 09:32:05 -0400 Received: from m12-11.163.com ([220.181.12.11]:52050 "EHLO m12-11.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753715AbbHYNcD (ORCPT ); Tue, 25 Aug 2015 09:32:03 -0400 From: Yaowei Bai To: akpm@linux-foundation.org, mgorman@suse.de, vbabka@suse.cz, mhocko@kernel.org, js1304@gmail.com, hannes@cmpxchg.org, alexander.h.duyck@redhat.com, sasha.levin@oracle.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] mm/page_alloc: add a helper function to check page before alloc/free Date: Tue, 25 Aug 2015 21:26:30 +0800 Message-Id: <1440509190-3622-1-git-send-email-bywxiaobai@163.com> X-Mailer: git-send-email 1.9.1 X-CM-TRANSID: C8CowEB5xkZ_bdxVE0xSAg--.2013S3 X-Coremail-Antispam: 1Uf129KBjvJXoWxAw17Jr4kKF4kKFy5ZrWkWFg_yoW5Cw45pa 1xJas7Aa1rtF98Krs7tr1DuF1rArn3trWxAa43Gwn5tFyavr4YyFyIkF1Fvr1furWxAryj qF47Jr1ru3W5C3JanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07jDKsUUUUUU= X-Originating-IP: [114.216.26.218] X-CM-SenderInfo: xe1z5x5dretxi6rwjhhfrp/1tbiuwZhT1O-vuzhRAAAsI Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3281 Lines: 103 The major portion of check_new_page() and free_pages_check() are same, introduce a helper function check_one_page() for simplification. Change in v2: - use bad_flags as parameter directly per Michal Hocko Signed-off-by: Yaowei Bai --- mm/page_alloc.c | 49 ++++++++++++++++++------------------------------- 1 file changed, 18 insertions(+), 31 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 5b5240b..0a0acdb 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -707,10 +707,9 @@ out: zone->free_area[order].nr_free++; } -static inline int free_pages_check(struct page *page) +static inline int check_one_page(struct page *page, unsigned long bad_flags) { const char *bad_reason = NULL; - unsigned long bad_flags = 0; if (unlikely(page_mapcount(page))) bad_reason = "nonzero mapcount"; @@ -718,9 +717,11 @@ static inline int free_pages_check(struct page *page) bad_reason = "non-NULL mapping"; if (unlikely(atomic_read(&page->_count) != 0)) bad_reason = "nonzero _count"; - if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) { - bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set"; - bad_flags = PAGE_FLAGS_CHECK_AT_FREE; + if (unlikely(page->flags & bad_flags)) { + if (bad_flags == PAGE_FLAGS_CHECK_AT_PREP) + bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set"; + else if (bad_flags == PAGE_FLAGS_CHECK_AT_FREE) + bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag set"; } #ifdef CONFIG_MEMCG if (unlikely(page->mem_cgroup)) @@ -730,6 +731,17 @@ static inline int free_pages_check(struct page *page) bad_page(page, bad_reason, bad_flags); return 1; } + return 0; +} + +static inline int free_pages_check(struct page *page) +{ + int ret = 0; + + ret = check_one_page(page, PAGE_FLAGS_CHECK_AT_FREE); + if (ret) + return ret; + page_cpupid_reset_last(page); if (page->flags & PAGE_FLAGS_CHECK_AT_PREP) page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; @@ -1287,32 +1299,7 @@ static inline void expand(struct zone *zone, struct page *page, */ static inline int check_new_page(struct page *page) { - const char *bad_reason = NULL; - unsigned long bad_flags = 0; - - if (unlikely(page_mapcount(page))) - bad_reason = "nonzero mapcount"; - if (unlikely(page->mapping != NULL)) - bad_reason = "non-NULL mapping"; - if (unlikely(atomic_read(&page->_count) != 0)) - bad_reason = "nonzero _count"; - if (unlikely(page->flags & __PG_HWPOISON)) { - bad_reason = "HWPoisoned (hardware-corrupted)"; - bad_flags = __PG_HWPOISON; - } - if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) { - bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set"; - bad_flags = PAGE_FLAGS_CHECK_AT_PREP; - } -#ifdef CONFIG_MEMCG - if (unlikely(page->mem_cgroup)) - bad_reason = "page still charged to cgroup"; -#endif - if (unlikely(bad_reason)) { - bad_page(page, bad_reason, bad_flags); - return 1; - } - return 0; + return check_one_page(page, PAGE_FLAGS_CHECK_AT_PREP); } static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags, -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/