From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752222AbbCWAKw (ORCPT ); Sun, 22 Mar 2015 20:10:52 -0400 Received: from mail-pd0-f176.google.com ([209.85.192.176]:35858 "EHLO mail-pd0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751951AbbCWAKt (ORCPT ); Sun, 22 Mar 2015 20:10:49 -0400 Date: Sun, 22 Mar 2015 17:10:46 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@eggly.anvils To: "Kirill A. Shutemov" cc: Andrew Morton , Andrea Arcangeli , Hugh Dickins , Dave Hansen , Mel Gorman , Rik van Riel , Vlastimil Babka , Christoph Lameter , Naoya Horiguchi , Steve Capper , "Aneesh Kumar K.V" , Johannes Weiner , Michal Hocko , Jerome Marchand , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 01/16] mm: consolidate all page-flags helpers in In-Reply-To: <1426784902-125149-2-git-send-email-kirill.shutemov@linux.intel.com> Message-ID: References: <1426784902-125149-1-git-send-email-kirill.shutemov@linux.intel.com> <1426784902-125149-2-git-send-email-kirill.shutemov@linux.intel.com> User-Agent: Alpine 2.11 (LSU 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 19 Mar 2015, Kirill A. Shutemov wrote: > We have page-flags helper function declarations/definitions spread over > several header files. Let's consolidate them in . > > Signed-off-by: Kirill A. Shutemov Acked-by: Hugh Dickins I find this one helpful (assuming it builds fine everywhere). I've several times recently found myself wanting to use PageAnon tests at a low level, and been frustrated by its positioning in linux/mm.h (see my 10/24). > --- > include/linux/hugetlb.h | 7 ---- > include/linux/ksm.h | 17 -------- > include/linux/mm.h | 81 -------------------------------------- > include/linux/page-flags.h | 96 ++++++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 96 insertions(+), 105 deletions(-) > > diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h > index 7b5785032049..1a782733a420 100644 > --- a/include/linux/hugetlb.h > +++ b/include/linux/hugetlb.h > @@ -41,8 +41,6 @@ extern int hugetlb_max_hstate __read_mostly; > struct hugepage_subpool *hugepage_new_subpool(long nr_blocks); > void hugepage_put_subpool(struct hugepage_subpool *spool); > > -int PageHuge(struct page *page); > - > void reset_vma_resv_huge_pages(struct vm_area_struct *vma); > int hugetlb_sysctl_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *); > int hugetlb_overcommit_handler(struct ctl_table *, int, void __user *, size_t *, loff_t *); > @@ -109,11 +107,6 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma, > > #else /* !CONFIG_HUGETLB_PAGE */ > > -static inline int PageHuge(struct page *page) > -{ > - return 0; > -} > - > static inline void reset_vma_resv_huge_pages(struct vm_area_struct *vma) > { > } > diff --git a/include/linux/ksm.h b/include/linux/ksm.h > index 3be6bb18562d..7ae216a39c9e 100644 > --- a/include/linux/ksm.h > +++ b/include/linux/ksm.h > @@ -35,18 +35,6 @@ static inline void ksm_exit(struct mm_struct *mm) > __ksm_exit(mm); > } > > -/* > - * A KSM page is one of those write-protected "shared pages" or "merged pages" > - * which KSM maps into multiple mms, wherever identical anonymous page content > - * is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any > - * anon_vma, but to that page's node of the stable tree. > - */ > -static inline int PageKsm(struct page *page) > -{ > - return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == > - (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM); > -} > - > static inline struct stable_node *page_stable_node(struct page *page) > { > return PageKsm(page) ? page_rmapping(page) : NULL; > @@ -87,11 +75,6 @@ static inline void ksm_exit(struct mm_struct *mm) > { > } > > -static inline int PageKsm(struct page *page) > -{ > - return 0; > -} > - > #ifdef CONFIG_MMU > static inline int ksm_madvise(struct vm_area_struct *vma, unsigned long start, > unsigned long end, int advice, unsigned long *vm_flags) > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 6571dd78e984..fb1fc38b01ce 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -494,15 +494,6 @@ static inline int page_count(struct page *page) > return atomic_read(&compound_head(page)->_count); > } > > -#ifdef CONFIG_HUGETLB_PAGE > -extern int PageHeadHuge(struct page *page_head); > -#else /* CONFIG_HUGETLB_PAGE */ > -static inline int PageHeadHuge(struct page *page_head) > -{ > - return 0; > -} > -#endif /* CONFIG_HUGETLB_PAGE */ > - > static inline bool __compound_tail_refcounted(struct page *page) > { > return !PageSlab(page) && !PageHeadHuge(page); > @@ -571,53 +562,6 @@ static inline void init_page_count(struct page *page) > atomic_set(&page->_count, 1); > } > > -/* > - * PageBuddy() indicate that the page is free and in the buddy system > - * (see mm/page_alloc.c). > - * > - * PAGE_BUDDY_MAPCOUNT_VALUE must be <= -2 but better not too close to > - * -2 so that an underflow of the page_mapcount() won't be mistaken > - * for a genuine PAGE_BUDDY_MAPCOUNT_VALUE. -128 can be created very > - * efficiently by most CPU architectures. > - */ > -#define PAGE_BUDDY_MAPCOUNT_VALUE (-128) > - > -static inline int PageBuddy(struct page *page) > -{ > - return atomic_read(&page->_mapcount) == PAGE_BUDDY_MAPCOUNT_VALUE; > -} > - > -static inline void __SetPageBuddy(struct page *page) > -{ > - VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page); > - atomic_set(&page->_mapcount, PAGE_BUDDY_MAPCOUNT_VALUE); > -} > - > -static inline void __ClearPageBuddy(struct page *page) > -{ > - VM_BUG_ON_PAGE(!PageBuddy(page), page); > - atomic_set(&page->_mapcount, -1); > -} > - > -#define PAGE_BALLOON_MAPCOUNT_VALUE (-256) > - > -static inline int PageBalloon(struct page *page) > -{ > - return atomic_read(&page->_mapcount) == PAGE_BALLOON_MAPCOUNT_VALUE; > -} > - > -static inline void __SetPageBalloon(struct page *page) > -{ > - VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page); > - atomic_set(&page->_mapcount, PAGE_BALLOON_MAPCOUNT_VALUE); > -} > - > -static inline void __ClearPageBalloon(struct page *page) > -{ > - VM_BUG_ON_PAGE(!PageBalloon(page), page); > - atomic_set(&page->_mapcount, -1); > -} > - > void put_page(struct page *page); > void put_pages_list(struct list_head *pages); > > @@ -1006,26 +950,6 @@ void page_address_init(void); > #define page_address_init() do { } while(0) > #endif > > -/* > - * On an anonymous page mapped into a user virtual memory area, > - * page->mapping points to its anon_vma, not to a struct address_space; > - * with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h. > - * > - * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled, > - * the PAGE_MAPPING_KSM bit may be set along with the PAGE_MAPPING_ANON bit; > - * and then page->mapping points, not to an anon_vma, but to a private > - * structure which KSM associates with that merged page. See ksm.h. > - * > - * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is currently never used. > - * > - * Please note that, confusingly, "page_mapping" refers to the inode > - * address_space which maps the page from disk; whereas "page_mapped" > - * refers to user virtual address space into which the page is mapped. > - */ > -#define PAGE_MAPPING_ANON 1 > -#define PAGE_MAPPING_KSM 2 > -#define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM) > - > extern struct address_space *page_mapping(struct page *page); > > /* Neutral page->mapping pointer to address_space or anon_vma or other */ > @@ -1045,11 +969,6 @@ struct address_space *page_file_mapping(struct page *page) > return page->mapping; > } > > -static inline int PageAnon(struct page *page) > -{ > - return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0; > -} > - > /* > * Return the pagecache index of the passed page. Regular pagecache pages > * use ->index whereas swapcache pages use ->private > diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h > index c851ff92d5b3..84d10b65cec6 100644 > --- a/include/linux/page-flags.h > +++ b/include/linux/page-flags.h > @@ -289,6 +289,47 @@ PAGEFLAG_FALSE(HWPoison) > #define __PG_HWPOISON 0 > #endif > > +/* > + * On an anonymous page mapped into a user virtual memory area, > + * page->mapping points to its anon_vma, not to a struct address_space; > + * with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h. > + * > + * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled, > + * the PAGE_MAPPING_KSM bit may be set along with the PAGE_MAPPING_ANON bit; > + * and then page->mapping points, not to an anon_vma, but to a private > + * structure which KSM associates with that merged page. See ksm.h. > + * > + * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is currently never used. > + * > + * Please note that, confusingly, "page_mapping" refers to the inode > + * address_space which maps the page from disk; whereas "page_mapped" > + * refers to user virtual address space into which the page is mapped. > + */ > +#define PAGE_MAPPING_ANON 1 > +#define PAGE_MAPPING_KSM 2 > +#define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM) > + > +static inline int PageAnon(struct page *page) > +{ > + return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0; > +} > + > +#ifdef CONFIG_KSM > +/* > + * A KSM page is one of those write-protected "shared pages" or "merged pages" > + * which KSM maps into multiple mms, wherever identical anonymous page content > + * is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any > + * anon_vma, but to that page's node of the stable tree. > + */ > +static inline int PageKsm(struct page *page) > +{ > + return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == > + (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM); > +} > +#else > +TESTPAGEFLAG_FALSE(Ksm) > +#endif > + > u64 stable_page_flags(struct page *page); > > static inline int PageUptodate(struct page *page) > @@ -426,6 +467,14 @@ static inline void ClearPageCompound(struct page *page) > > #endif /* !PAGEFLAGS_EXTENDED */ > > +#ifdef CONFIG_HUGETLB_PAGE > +int PageHuge(struct page *page); > +int PageHeadHuge(struct page *page); > +#else > +TESTPAGEFLAG_FALSE(Huge) > +TESTPAGEFLAG_FALSE(HeadHuge) > +#endif > + > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > /* > * PageHuge() only returns true for hugetlbfs pages, but not for > @@ -480,6 +529,53 @@ static inline int PageTransTail(struct page *page) > #endif > > /* > + * PageBuddy() indicate that the page is free and in the buddy system > + * (see mm/page_alloc.c). > + * > + * PAGE_BUDDY_MAPCOUNT_VALUE must be <= -2 but better not too close to > + * -2 so that an underflow of the page_mapcount() won't be mistaken > + * for a genuine PAGE_BUDDY_MAPCOUNT_VALUE. -128 can be created very > + * efficiently by most CPU architectures. > + */ > +#define PAGE_BUDDY_MAPCOUNT_VALUE (-128) > + > +static inline int PageBuddy(struct page *page) > +{ > + return atomic_read(&page->_mapcount) == PAGE_BUDDY_MAPCOUNT_VALUE; > +} > + > +static inline void __SetPageBuddy(struct page *page) > +{ > + VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page); > + atomic_set(&page->_mapcount, PAGE_BUDDY_MAPCOUNT_VALUE); > +} > + > +static inline void __ClearPageBuddy(struct page *page) > +{ > + VM_BUG_ON_PAGE(!PageBuddy(page), page); > + atomic_set(&page->_mapcount, -1); > +} > + > +#define PAGE_BALLOON_MAPCOUNT_VALUE (-256) > + > +static inline int PageBalloon(struct page *page) > +{ > + return atomic_read(&page->_mapcount) == PAGE_BALLOON_MAPCOUNT_VALUE; > +} > + > +static inline void __SetPageBalloon(struct page *page) > +{ > + VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page); > + atomic_set(&page->_mapcount, PAGE_BALLOON_MAPCOUNT_VALUE); > +} > + > +static inline void __ClearPageBalloon(struct page *page) > +{ > + VM_BUG_ON_PAGE(!PageBalloon(page), page); > + atomic_set(&page->_mapcount, -1); > +} > + > +/* > * If network-based swap is enabled, sl*b must keep track of whether pages > * were allocated from pfmemalloc reserves. > */ > -- > 2.1.4