From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f49.google.com (mail-pa0-f49.google.com [209.85.220.49]) by kanga.kvack.org (Postfix) with ESMTP id 342D06B0255 for ; Thu, 27 Aug 2015 08:55:55 -0400 (EDT) Received: by pacgr6 with SMTP id gr6so7377114pac.3 for ; Thu, 27 Aug 2015 05:55:55 -0700 (PDT) Received: from m12-14.163.com (m12-14.163.com. [220.181.12.14]) by mx.google.com with ESMTP id so1si3581843pbc.33.2015.08.27.05.55.52 for ; Thu, 27 Aug 2015 05:55:54 -0700 (PDT) From: Yaowei Bai Subject: [PATCH v3] mm/page_alloc: add a helper function to check page before alloc/free Date: Thu, 27 Aug 2015 20:51:57 +0800 Message-Id: <1440679917-3507-1-git-send-email-bywxiaobai@163.com> Sender: owner-linux-mm@kvack.org List-ID: 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 The major portion of check_new_page() and free_pages_check() are same, introduce a helper function check_one_page() for simplification. Change in v3: - add the missed __PG_HWPOISON check per Michal Hocko Change in v2: - use bad_flags as parameter directly per Michal Hocko Signed-off-by: Yaowei Bai --- mm/page_alloc.c | 54 +++++++++++++++++++++++------------------------------- 1 file changed, 23 insertions(+), 31 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 5b5240b..0c9c82a 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 +717,16 @@ 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 (bad_flags == PAGE_FLAGS_CHECK_AT_PREP) { + if (unlikely(page->flags & bad_flags)) + bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set"; + if (unlikely(page->flags & __PG_HWPOISON)) { + bad_reason = "HWPoisoned (hardware-corrupted)"; + bad_flags = __PG_HWPOISON; + } + } else if (bad_flags == PAGE_FLAGS_CHECK_AT_FREE) { + if (unlikely(page->flags & bad_flags)) + bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag set"; } #ifdef CONFIG_MEMCG if (unlikely(page->mem_cgroup)) @@ -730,6 +736,17 @@ 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 +1304,7 @@ 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, 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