diff options
| -rw-r--r-- | fs/hugetlbfs/inode.c | 74 | ||||
| -rw-r--r-- | include/linux/hugetlb.h | 8 | ||||
| -rw-r--r-- | mm/hugetlb.c | 136 |
3 files changed, 154 insertions, 64 deletions
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index b3519528994..1a1c2fcb782 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -56,48 +56,10 @@ static void huge_pagevec_release(struct pagevec *pvec) pagevec_reinit(pvec); } -/* - * huge_pages_needed tries to determine the number of new huge pages that - * will be required to fully populate this VMA. This will be equal to - * the size of the VMA in huge pages minus the number of huge pages - * (covered by this VMA) that are found in the page cache. - * - * Result is in bytes to be compatible with is_hugepage_mem_enough() - */ -static unsigned long -huge_pages_needed(struct address_space *mapping, struct vm_area_struct *vma) -{ - int i; - struct pagevec pvec; - unsigned long start = vma->vm_start; - unsigned long end = vma->vm_end; - unsigned long hugepages = (end - start) >> HPAGE_SHIFT; - pgoff_t next = vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT); - pgoff_t endpg = next + hugepages; - - pagevec_init(&pvec, 0); - while (next < endpg) { - if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) - break; - for (i = 0; i < pagevec_count(&pvec); i++) { - struct page *page = pvec.pages[i]; - if (page->index > next) - next = page->index; - if (page->index >= endpg) - break; - next++; - hugepages--; - } - huge_pagevec_release(&pvec); - } - return hugepages << HPAGE_SHIFT; -} - static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma) { struct inode *inode = file->f_dentry->d_inode; - struct address_space *mapping = inode->i_mapping; - unsigned long bytes; + struct hugetlbfs_inode_info *info = HUGETLBFS_I(inode); loff_t len, vma_len; int ret; @@ -113,10 +75,6 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma) if (vma->vm_end - vma->vm_start < HPAGE_SIZE) return -EINVAL; - bytes = huge_pages_needed(mapping, vma); - if (!is_hugepage_mem_enough(bytes)) - return -ENOMEM; - vma_len = (loff_t)(vma->vm_end - vma->vm_start); mutex_lock(&inode->i_mutex); @@ -129,6 +87,10 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma) if (!(vma->vm_flags & VM_WRITE) && len > inode->i_size) goto out; + if (vma->vm_flags & VM_MAYSHARE) + if (hugetlb_extend_reservation(info, len >> HPAGE_SHIFT) != 0) + goto out; + ret = 0; hugetlb_prefault_arch_hook(vma->vm_mm); if (inode->i_size < len) @@ -227,13 +189,18 @@ static void truncate_huge_page(struct page *page) put_page(page); } -static void truncate_hugepages(struct address_space *mapping, loff_t lstart) +static void truncate_hugepages(struct inode *inode, loff_t lstart) { + struct address_space *mapping = &inode->i_data; const pgoff_t start = lstart >> HPAGE_SHIFT; struct pagevec pvec; pgoff_t next; int i; + hugetlb_truncate_reservation(HUGETLBFS_I(inode), + lstart >> HPAGE_SHIFT); + if (!mapping->nrpages) + return; pagevec_init(&pvec, 0); next = start; while (1) { @@ -262,8 +229,7 @@ static void truncate_hugepages(struct address_space *mapping, loff_t lstart) static void hugetlbfs_delete_inode(struct inode *inode) { - if (inode->i_data.nrpages) - truncate_hugepages(&inode->i_data, 0); + truncate_hugepages(inode, 0); clear_inode(inode); } @@ -296,8 +262,7 @@ static void hugetlbfs_forget_inode(struct inode *inode) inode->i_state |= I_FREEING; inodes_stat.nr_inodes--; spin_unlock(&inode_lock); - if (inode->i_data.nrpages) - truncate_hugepages(&inode->i_data, 0); + truncate_hugepages(inode, 0); clear_inode(inode); destroy_inode(inode); } @@ -356,7 +321,7 @@ static int hugetlb_vmtruncate(struct inode *inode, loff_t offset) if (!prio_tree_empty(&mapping->i_mmap)) hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff); spin_unlock(&mapping->i_mmap_lock); - truncate_hugepages(mapping, offset); + truncate_hugepages(inode, offset); return 0; } @@ -573,6 +538,7 @@ static struct inode *hugetlbfs_alloc_inode(struct super_block *sb) hugetlbfs_inc_free_inodes(sbinfo); return NULL; } + p->prereserved_hpages = 0; return &p->vfs_inode; } @@ -805,9 +771,6 @@ struct file *hugetlb_zero_setup(size_t size) if (!can_do_hugetlb_shm()) return ERR_PTR(-EPERM); - if (!is_hugepage_mem_enough(size)) - return ERR_PTR(-ENOMEM); - if (!user_shm_lock(size, current->user)) return ERR_PTR(-ENOMEM); @@ -831,6 +794,11 @@ struct file *hugetlb_zero_setup(size_t size) if (!inode) goto out_file; + error = -ENOMEM; + if (hugetlb_extend_reservation(HUGETLBFS_I(inode), + size >> HPAGE_SHIFT) != 0) + goto out_inode; + d_instantiate(dentry, inode); inode->i_size = size; inode->i_nlink = 0; @@ -841,6 +809,8 @@ struct file *hugetlb_zero_setup(size_t size) file->f_mode = FMODE_WRITE | FMODE_READ; return file; +out_inode: + iput(inode); out_file: put_filp(file); out_dentry: diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index fa83836b63d..cafe73eecb0 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -20,7 +20,6 @@ void unmap_hugepage_range(struct vm_area_struct *, unsigned long, unsigned long) int hugetlb_prefault(struct address_space *, struct vm_area_struct *); int hugetlb_report_meminfo(char *); int hugetlb_report_node_meminfo(int, char *); -int is_hugepage_mem_enough(size_t); unsigned long hugetlb_total_pages(void); struct page *alloc_huge_page(struct vm_area_struct *, unsigned long); void free_huge_page(struct page *); @@ -89,7 +88,6 @@ static inline unsigned long hugetlb_total_pages(void) #define copy_hugetlb_page_range(src, dst, vma) ({ BUG(); 0; }) #define hugetlb_prefault(mapping, vma) ({ BUG(); 0; }) #define unmap_hugepage_range(vma, start, end) BUG() -#define is_hugepage_mem_enough(size) 0 #define hugetlb_report_meminfo(buf) 0 #define hugetlb_report_node_meminfo(n, buf) 0 #define follow_huge_pmd(mm, addr, pmd, write) NULL @@ -132,6 +130,8 @@ struct hugetlbfs_sb_info { struct hugetlbfs_inode_info { struct shared_policy policy; + /* Protected by the (global) hugetlb_lock */ + unsigned long prereserved_hpages; struct inode vfs_inode; }; @@ -148,6 +148,10 @@ static inline struct hugetlbfs_sb_info *HUGETLBFS_SB(struct super_block *sb) extern struct file_operations hugetlbfs_file_operations; extern struct vm_operations_struct hugetlb_vm_ops; struct file *hugetlb_zero_setup(size_t); +int hugetlb_extend_reservation(struct hugetlbfs_inode_info *info, + unsigned long atleast_hpages); +void hugetlb_truncate_reservation(struct hugetlbfs_inode_info *info, + unsigned long atmost_hpages); int hugetlb_get_quota(struct address_space *mapping); void hugetlb_put_quota(struct address_space *mapping); diff --git a/mm/hugetlb.c b/mm/hugetlb.c index d5987a87bbe..27fad5d9bcf 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -22,7 +22,7 @@ #include "internal.h" const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; -static unsigned long nr_huge_pages, free_huge_pages; +static unsigned long nr_huge_pages, free_huge_pages, reserved_huge_pages; unsigned long max_huge_pages; static struct list_head hugepage_freelists[MAX_NUMNODES]; static unsigned int nr_huge_pages_node[MAX_NUMNODES]; @@ -120,17 +120,136 @@ void free_huge_page(struct page *page) struct page *alloc_huge_page(struct vm_area_struct *vma, unsigned long addr) { + struct inode *inode = vma->vm_file->f_dentry->d_inode; struct page *page; + int use_reserve = 0; + unsigned long idx; spin_lock(&hugetlb_lock); - page = dequeue_huge_page(vma, addr); - if (!page) { - spin_unlock(&hugetlb_lock); - return NULL; + + if (vma->vm_flags & VM_MAYSHARE) { + + /* idx = radix tree index, i.e. offset into file in + * HPAGE_SIZE units */ + idx = ((addr - vma->vm_start) >> HPAGE_SHIFT) + + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT)); + + /* The hugetlbfs specific inode info stores the number + * of "guaranteed available" (huge) pages. That is, + * the first 'prereserved_hpages' pages of the inode + * are either already instantiated, or have been + * pre-reserved (by hugetlb_reserve_for_inode()). Here + * we're in the process of instantiating the page, so + * we use this to determine whether to draw from the + * pre-reserved pool or the truly free pool. */ + if (idx < HUGETLBFS_I(inode)->prereserved_hpages) + use_reserve = 1; + } + + if (!use_reserve) { + if (free_huge_pages <= reserved_huge_pages) + goto fail; + } else { + BUG_ON(reserved_huge_pages == 0); + reserved_huge_pages--; } + + page = dequeue_huge_page(vma, addr); + if (!page) + goto fail; + spin_unlock(&hugetlb_lock); set_page_refcounted(page); return page; + + fail: + WARN_ON(use_reserve); /* reserved allocations shouldn't fail */ + spin_unlock(&hugetlb_lock); + return NULL; +} + +/* hugetlb_extend_reservation() + * + * Ensure that at least 'atleast' hugepages are, and will remain, + * available to instantiate the first 'atleast' pages of the given + * inode. If the inode doesn't already have this many pages reserved + * or instantiated, set aside some hugepages in the reserved pool to + * satisfy later faults (or fail now if there aren't enough, rather + * than getting the SIGBUS later). + */ +int hugetlb_extend_reservation(struct hugetlbfs_inode_info *info, + unsigned long atleast) +{ + struct inode *inode = &info->vfs_inode; + unsigned long change_in_reserve = 0; + int ret = 0; + + spin_lock(&hugetlb_lock); + read_lock_irq(&inode->i_mapping->tree_lock); + + if (info->prereserved_hpages >= atleast) + goto out; + + /* Because we always call this on shared mappings, none of the + * pages beyond info->prereserved_hpages can have been + * instantiated, so we need to reserve all of them now. */ + change_in_reserve = atleast - info->prereserved_hpages; + + if ((reserved_huge_pages + change_in_reserve) > free_huge_pages) { + ret = -ENOMEM; + goto out; + } + + reserved_huge_pages += change_in_reserve; + info->prereserved_hpages = atleast; + + out: + read_unlock_irq(&inode->i_mapping->tree_lock); + spin_unlock(&hugetlb_lock); + + return ret; +} + +/* hugetlb_truncate_reservation() + * + * This returns pages reserved for the given inode to the general free + * hugepage pool. If the inode has any pages prereserved, but not + * instantiated, beyond offset (atmost << HPAGE_SIZE), then release + * them. + */ +void hugetlb_truncate_reservation(struct hugetlbfs_inode_info *info, + unsigned long atmost) +{ + struct inode *inode = &info->vfs_inode; + struct address_space *mapping = inode->i_mapping; + unsigned long idx; + unsigned long change_in_reserve = 0; + struct page *page; + + spin_lock(&hugetlb_lock); + read_lock_irq(&inode->i_mapping->tree_lock); + + if (info->prereserved_hpages <= atmost) + goto out; + + /* Count pages which were reserved, but not instantiated, and + * which we can now release. */ + for (idx = atmost; idx < info->prereserved_hpages; idx++) { + page = radix_tree_lookup(&mapping->page_tree, idx); + if (!page) + /* Pages which are already instantiated can't + * be unreserved (and in fact have already + * been removed from the reserved pool) */ + change_in_reserve++; + } + + BUG_ON(reserved_huge_pages < change_in_reserve); + reserved_huge_pages -= change_in_reserve; + info->prereserved_hpages = atmost; + + out: + read_unlock_irq(&inode->i_mapping->tree_lock); + spin_unlock(&hugetlb_lock); } static int __init hugetlb_init(void) @@ -238,9 +357,11 @@ int hugetlb_report_meminfo(char *buf) return sprintf(buf, "HugePages_Total: %5lu\n" "HugePages_Free: %5lu\n" + "HugePages_Rsvd: %5lu\n" "Hugepagesize: %5lu kB\n", nr_huge_pages, free_huge_pages, + reserved_huge_pages, HPAGE_SIZE/1024); } @@ -253,11 +374,6 @@ int hugetlb_report_node_meminfo(int nid, char *buf) nid, free_huge_pages_node[nid]); } -int is_hugepage_mem_enough(size_t size) -{ - return (size + ~HPAGE_MASK)/HPAGE_SIZE <= free_huge_pages; -} - /* Return the number pages of memory we physically have, in PAGE_SIZE units. */ unsigned long hugetlb_total_pages(void) { |