From e8c6158fef15a1532bd5242a0cd88565eedabe61 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Wed, 15 Apr 2015 16:13:08 -0700 Subject: mm: consolidate all page-flags helpers in Currently we take a naive approach to page flags on compound pages - we set the flag on the page without consideration if the flag makes sense for tail page or for compound page in general. This patchset try to sort this out by defining per-flag policy on what need to be done if page-flag helper operate on compound page. The last patch in the patchset also sanitizes usege of page->mapping for tail pages. We don't define the meaning of page->mapping for tail pages. Currently it's always NULL, which can be inconsistent with head page and potentially lead to problems. For now I caught one case of illegal usage of page flags or ->mapping: sound subsystem allocates pages with __GFP_COMP and maps them with PTEs. It leads to setting dirty bit on tail pages and access to tail_page's ->mapping. I don't see any bad behaviour caused by this, but worth fixing anyway. This patchset makes more sense if you take my THP refcounting into account: we will see more compound pages mapped with PTEs and we need to define behaviour of flags on compound pages to avoid bugs. This patch (of 16): We have page-flags helper function declarations/definitions spread over several header files. Let's consolidate them in . Signed-off-by: Kirill A. Shutemov Cc: Andrea Arcangeli Acked-by: Hugh Dickins Cc: Dave Hansen Cc: Mel Gorman Cc: Rik van Riel Cc: Vlastimil Babka Cc: Christoph Lameter Cc: Naoya Horiguchi Cc: Steve Capper Cc: "Aneesh Kumar K.V" Cc: Johannes Weiner Cc: Michal Hocko Cc: Jerome Marchand Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/hugetlb.h | 7 ------- 1 file changed, 7 deletions(-) (limited to 'include/linux/hugetlb.h') 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) { } -- cgit v1.2.3 From c6a918200c4f4ebf74b7e1ae4fea9115c7b297f8 Mon Sep 17 00:00:00 2001 From: Mike Kravetz Date: Wed, 15 Apr 2015 16:13:36 -0700 Subject: hugetlbfs: add minimum size tracking fields to subpool structure hugetlbfs allocates huge pages from the global pool as needed. Even if the global pool contains a sufficient number pages for the filesystem size at mount time, those global pages could be grabbed for some other use. As a result, filesystem huge page allocations may fail due to lack of pages. Applications such as a database want to use huge pages for performance reasons. hugetlbfs filesystem semantics with ownership and modes work well to manage access to a pool of huge pages. However, the application would like some reasonable assurance that allocations will not fail due to a lack of huge pages. At application startup time, the application would like to configure itself to use a specific number of huge pages. Before starting, the application can check to make sure that enough huge pages exist in the system global pools. However, there are no guarantees that those pages will be available when needed by the application. What the application wants is exclusive use of a subset of huge pages. Add a new hugetlbfs mount option 'min_size=' to indicate that the specified number of pages will be available for use by the filesystem. At mount time, this number of huge pages will be reserved for exclusive use of the filesystem. If there is not a sufficient number of free pages, the mount will fail. As pages are allocated to and freeed from the filesystem, the number of reserved pages is adjusted so that the specified minimum is maintained. This patch (of 4): Add a field to the subpool structure to indicate the minimimum number of huge pages to always be used by this subpool. This minimum count includes allocated pages as well as reserved pages. If the minimum number of pages for the subpool have not been allocated, pages are reserved up to this minimum. An additional field (rsv_hpages) is used to track the number of pages reserved to meet this minimum size. The hstate pointer in the subpool is convenient to have when reserving and unreserving the pages. Signed-off-by: Mike Kravetz Cc: Davidlohr Bueso Cc: Aneesh Kumar Cc: Joonsoo Kim Cc: Andi Kleen Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/hugetlb.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'include/linux/hugetlb.h') diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 1a782733a420..d1a77b87408d 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -22,7 +22,13 @@ struct mmu_gather; struct hugepage_subpool { spinlock_t lock; long count; - long max_hpages, used_hpages; + long max_hpages; /* Maximum huge pages or -1 if no maximum. */ + long used_hpages; /* Used count against maximum, includes */ + /* both alloced and reserved pages. */ + struct hstate *hstate; + long min_hpages; /* Minimum huge pages or -1 if no minimum. */ + long rsv_hpages; /* Pages reserved against global pool to */ + /* sasitfy minimum size. */ }; struct resv_map { -- cgit v1.2.3 From 7ca02d0ae586fe7df59632966a64f3f1a756ef05 Mon Sep 17 00:00:00 2001 From: Mike Kravetz Date: Wed, 15 Apr 2015 16:13:42 -0700 Subject: hugetlbfs: accept subpool min_size mount option and setup accordingly Make 'min_size=' be an option when mounting a hugetlbfs. This option takes the same value as the 'size' option. min_size can be specified without specifying size. If both are specified, min_size must be less that or equal to size else the mount will fail. If min_size is specified, then at mount time an attempt is made to reserve min_size pages. If the reservation fails, the mount fails. At umount time, the reserved pages are released. Signed-off-by: Mike Kravetz Cc: Davidlohr Bueso Cc: Aneesh Kumar Cc: Joonsoo Kim Cc: Andi Kleen Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/hugetlb.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/hugetlb.h') diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index d1a77b87408d..5713c49a4a5c 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -44,7 +44,8 @@ extern int hugetlb_max_hstate __read_mostly; #define for_each_hstate(h) \ for ((h) = hstates; (h) < &hstates[hugetlb_max_hstate]; (h)++) -struct hugepage_subpool *hugepage_new_subpool(long nr_blocks); +struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages, + long min_hpages); void hugepage_put_subpool(struct hugepage_subpool *spool); void reset_vma_resv_huge_pages(struct vm_area_struct *vma); -- cgit v1.2.3 From 7e1f049efb86bd86c06b80eeac0ef80cdeb8c0e7 Mon Sep 17 00:00:00 2001 From: Naoya Horiguchi Date: Wed, 15 Apr 2015 16:14:41 -0700 Subject: mm: hugetlb: cleanup using paeg_huge_active() Now we have an easy access to hugepages' activeness, so existing helpers to get the information can be cleaned up. [akpm@linux-foundation.org: s/PageHugeActive/page_huge_active/] Signed-off-by: Naoya Horiguchi Cc: Hugh Dickins Reviewed-by: Michal Hocko Cc: Mel Gorman Cc: Johannes Weiner Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/hugetlb.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux/hugetlb.h') diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 5713c49a4a5c..205026175c42 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -84,7 +84,6 @@ void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed); int dequeue_hwpoisoned_huge_page(struct page *page); bool isolate_huge_page(struct page *page, struct list_head *list); void putback_active_hugepage(struct page *page); -bool is_hugepage_active(struct page *page); void free_huge_page(struct page *page); #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE @@ -152,7 +151,6 @@ static inline bool isolate_huge_page(struct page *page, struct list_head *list) return false; } #define putback_active_hugepage(p) do {} while (0) -#define is_hugepage_active(x) false static inline unsigned long hugetlb_change_protection(struct vm_area_struct *vma, unsigned long address, unsigned long end, pgprot_t newprot) -- cgit v1.2.3