X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=mm%2Fhugetlb.c;h=02561175ca078341bbf3ecb7ea448864ddf2ef7e;hb=refs%2Fheads%2Fvserver;hp=2894563b76aa1085157f778c969ea343097cd45d;hpb=43bc926fffd92024b46cafaf7350d669ba9ca884;p=linux-2.6.git diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 2894563b7..02561175c 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -23,7 +23,7 @@ #include "internal.h" const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL; -static unsigned long nr_huge_pages, free_huge_pages, reserved_huge_pages; +static unsigned long nr_huge_pages, free_huge_pages, resv_huge_pages; unsigned long max_huge_pages; static struct list_head hugepage_freelists[MAX_NUMNODES]; static unsigned int nr_huge_pages_node[MAX_NUMNODES]; @@ -45,14 +45,14 @@ static void clear_huge_page(struct page *page, unsigned long addr) } static void copy_huge_page(struct page *dst, struct page *src, - unsigned long addr) + unsigned long addr, struct vm_area_struct *vma) { int i; might_sleep(); for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) { cond_resched(); - copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE); + copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma); } } @@ -73,8 +73,8 @@ static struct page *dequeue_huge_page(struct vm_area_struct *vma, struct zone **z; for (z = zonelist->zones; *z; z++) { - nid = (*z)->zone_pgdat->node_id; - if (cpuset_zone_allowed(*z, GFP_HIGHUSER) && + nid = zone_to_nid(*z); + if (cpuset_zone_allowed_softwall(*z, GFP_HIGHUSER) && !list_empty(&hugepage_freelists[nid])) break; } @@ -110,7 +110,7 @@ static int alloc_fresh_huge_page(void) if (nid == MAX_NUMNODES) nid = first_node(node_online_map); if (page) { - page[1].lru.next = (void *)free_huge_page; /* dtor */ + set_compound_page_dtor(page, free_huge_page); spin_lock(&hugetlb_lock); nr_huge_pages++; nr_huge_pages_node[page_to_nid(page)]++; @@ -124,39 +124,13 @@ static int alloc_fresh_huge_page(void) static 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); - - 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--; - } + if (vma->vm_flags & VM_MAYSHARE) + resv_huge_pages--; + else if (free_huge_pages <= resv_huge_pages) + goto fail; page = dequeue_huge_page(vma, addr); if (!page) @@ -166,96 +140,11 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma, set_page_refcounted(page); return page; - fail: - WARN_ON(use_reserve); /* reserved allocations shouldn't fail */ +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) { unsigned long i; @@ -289,7 +178,7 @@ static void update_and_free_page(struct page *page) { int i; nr_huge_pages--; - nr_huge_pages_node[page_zone(page)->zone_pgdat->node_id]--; + nr_huge_pages_node[page_to_nid(page)]--; for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) { page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced | 1 << PG_dirty | 1 << PG_active | 1 << PG_reserved | @@ -303,7 +192,8 @@ static void update_and_free_page(struct page *page) #ifdef CONFIG_HIGHMEM static void try_to_free_low(unsigned long count) { - int i, nid; + int i; + for (i = 0; i < MAX_NUMNODES; ++i) { struct page *page, *next; list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) { @@ -311,9 +201,8 @@ static void try_to_free_low(unsigned long count) continue; list_del(&page->lru); update_and_free_page(page); - nid = page_zone(page)->zone_pgdat->node_id; free_huge_pages--; - free_huge_pages_node[nid]--; + free_huge_pages_node[page_to_nid(page)]--; if (count >= nr_huge_pages) return; } @@ -335,7 +224,7 @@ static unsigned long set_max_huge_pages(unsigned long count) return nr_huge_pages; spin_lock(&hugetlb_lock); - count = max(count, reserved_huge_pages); + count = max(count, resv_huge_pages); try_to_free_low(count); while (count < nr_huge_pages) { struct page *page = dequeue_huge_page(NULL, 0); @@ -362,11 +251,11 @@ int hugetlb_report_meminfo(char *buf) return sprintf(buf, "HugePages_Total: %5lu\n" "HugePages_Free: %5lu\n" - "HugePages_Rsvd: %5lu\n" + "HugePages_Rsvd: %5lu\n" "Hugepagesize: %5lu kB\n", nr_huge_pages, free_huge_pages, - reserved_huge_pages, + resv_huge_pages, HPAGE_SIZE/1024); } @@ -456,7 +345,6 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src, entry = *src_pte; ptepage = pte_page(entry); get_page(ptepage); - add_mm_counter(dst, file_rss, HPAGE_SIZE / PAGE_SIZE); set_huge_pte_at(dst, addr, dst_pte, entry); } spin_unlock(&src->page_table_lock); @@ -468,40 +356,68 @@ nomem: return -ENOMEM; } -void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, - unsigned long end) +void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, + unsigned long end) { struct mm_struct *mm = vma->vm_mm; unsigned long address; pte_t *ptep; pte_t pte; struct page *page; + struct page *tmp; + /* + * A page gathering list, protected by per file i_mmap_lock. The + * lock is used to avoid list corruption from multiple unmapping + * of the same page since we are using page->lru. + */ + LIST_HEAD(page_list); WARN_ON(!is_vm_hugetlb_page(vma)); BUG_ON(start & ~HPAGE_MASK); BUG_ON(end & ~HPAGE_MASK); spin_lock(&mm->page_table_lock); - - /* Update high watermark before we lower rss */ - update_hiwater_rss(mm); - for (address = start; address < end; address += HPAGE_SIZE) { ptep = huge_pte_offset(mm, address); if (!ptep) continue; + if (huge_pmd_unshare(mm, &address, ptep)) + continue; + pte = huge_ptep_get_and_clear(mm, address, ptep); if (pte_none(pte)) continue; page = pte_page(pte); - put_page(page); - add_mm_counter(mm, file_rss, (int) -(HPAGE_SIZE / PAGE_SIZE)); + if (pte_dirty(pte)) + set_page_dirty(page); + list_add(&page->lru, &page_list); } - spin_unlock(&mm->page_table_lock); flush_tlb_range(vma, start, end); + list_for_each_entry_safe(page, tmp, &page_list, lru) { + list_del(&page->lru); + put_page(page); + } +} + +void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, + unsigned long end) +{ + /* + * It is undesirable to test vma->vm_file as it should be non-null + * for valid hugetlb area. However, vm_file will be NULL in the error + * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails, + * do_mmap_pgoff() nullifies vma->vm_file before calling this function + * to clean up. Since no pte has actually been setup, it is safe to + * do nothing in this case. + */ + if (vma->vm_file) { + spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); + __unmap_hugepage_range(vma, start, end); + spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); + } } static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, @@ -529,7 +445,7 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, } spin_unlock(&mm->page_table_lock); - copy_huge_page(new_page, old_page, address); + copy_huge_page(new_page, old_page, address, vma); spin_lock(&mm->page_table_lock); ptep = huge_pte_offset(mm, address & HPAGE_MASK); @@ -566,6 +482,9 @@ int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, retry: page = find_lock_page(mapping, idx); if (!page) { + size = i_size_read(mapping->host) >> HPAGE_SHIFT; + if (idx >= size) + goto out; if (hugetlb_get_quota(mapping)) goto out; page = alloc_huge_page(vma, address); @@ -600,7 +519,6 @@ retry: if (!pte_none(*ptep)) goto backout; - add_mm_counter(mm, file_rss, HPAGE_SIZE / PAGE_SIZE); new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE) && (vma->vm_flags & VM_SHARED))); set_huge_pte_at(mm, address, ptep, new_pte); @@ -738,11 +656,14 @@ void hugetlb_change_protection(struct vm_area_struct *vma, BUG_ON(address >= end); flush_cache_range(vma, address, end); + spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); spin_lock(&mm->page_table_lock); for (; address < end; address += HPAGE_SIZE) { ptep = huge_pte_offset(mm, address); if (!ptep) continue; + if (huge_pmd_unshare(mm, &address, ptep)) + continue; if (!pte_none(*ptep)) { pte = huge_ptep_get_and_clear(mm, address, ptep); pte = pte_mkhuge(pte_modify(pte, newprot)); @@ -751,7 +672,161 @@ void hugetlb_change_protection(struct vm_area_struct *vma, } } spin_unlock(&mm->page_table_lock); + spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); flush_tlb_range(vma, start, end); } +struct file_region { + struct list_head link; + long from; + long to; +}; + +static long region_add(struct list_head *head, long f, long t) +{ + struct file_region *rg, *nrg, *trg; + + /* Locate the region we are either in or before. */ + list_for_each_entry(rg, head, link) + if (f <= rg->to) + break; + + /* Round our left edge to the current segment if it encloses us. */ + if (f > rg->from) + f = rg->from; + + /* Check for and consume any regions we now overlap with. */ + nrg = rg; + list_for_each_entry_safe(rg, trg, rg->link.prev, link) { + if (&rg->link == head) + break; + if (rg->from > t) + break; + + /* If this area reaches higher then extend our area to + * include it completely. If this is not the first area + * which we intend to reuse, free it. */ + if (rg->to > t) + t = rg->to; + if (rg != nrg) { + list_del(&rg->link); + kfree(rg); + } + } + nrg->from = f; + nrg->to = t; + return 0; +} + +static long region_chg(struct list_head *head, long f, long t) +{ + struct file_region *rg, *nrg; + long chg = 0; + + /* Locate the region we are before or in. */ + list_for_each_entry(rg, head, link) + if (f <= rg->to) + break; + + /* If we are below the current region then a new region is required. + * Subtle, allocate a new region at the position but make it zero + * size such that we can guarentee to record the reservation. */ + if (&rg->link == head || t < rg->from) { + nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); + if (nrg == 0) + return -ENOMEM; + nrg->from = f; + nrg->to = f; + INIT_LIST_HEAD(&nrg->link); + list_add(&nrg->link, rg->link.prev); + + return t - f; + } + + /* Round our left edge to the current segment if it encloses us. */ + if (f > rg->from) + f = rg->from; + chg = t - f; + + /* Check for and consume any regions we now overlap with. */ + list_for_each_entry(rg, rg->link.prev, link) { + if (&rg->link == head) + break; + if (rg->from > t) + return chg; + + /* We overlap with this area, if it extends futher than + * us then we must extend ourselves. Account for its + * existing reservation. */ + if (rg->to > t) { + chg += rg->to - t; + t = rg->to; + } + chg -= rg->to - rg->from; + } + return chg; +} + +static long region_truncate(struct list_head *head, long end) +{ + struct file_region *rg, *trg; + long chg = 0; + + /* Locate the region we are either in or before. */ + list_for_each_entry(rg, head, link) + if (end <= rg->to) + break; + if (&rg->link == head) + return 0; + + /* If we are in the middle of a region then adjust it. */ + if (end > rg->from) { + chg = rg->to - end; + rg->to = end; + rg = list_entry(rg->link.next, typeof(*rg), link); + } + + /* Drop any remaining regions. */ + list_for_each_entry_safe(rg, trg, rg->link.prev, link) { + if (&rg->link == head) + break; + chg += rg->to - rg->from; + list_del(&rg->link); + kfree(rg); + } + return chg; +} + +static int hugetlb_acct_memory(long delta) +{ + int ret = -ENOMEM; + + spin_lock(&hugetlb_lock); + if ((delta + resv_huge_pages) <= free_huge_pages) { + resv_huge_pages += delta; + ret = 0; + } + spin_unlock(&hugetlb_lock); + return ret; +} + +int hugetlb_reserve_pages(struct inode *inode, long from, long to) +{ + long ret, chg; + + chg = region_chg(&inode->i_mapping->private_list, from, to); + if (chg < 0) + return chg; + ret = hugetlb_acct_memory(chg); + if (ret < 0) + return ret; + region_add(&inode->i_mapping->private_list, from, to); + return 0; +} + +void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed) +{ + long chg = region_truncate(&inode->i_mapping->private_list, offset); + hugetlb_acct_memory(freed - chg); +}