X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=blobdiff_plain;f=mm%2Fhugetlb.c;h=6f048fcc749ca48b3bae0a1a37a792f15e0c203d;hp=f10cc274a7d90b32287800ebcd614787ab9c5692;hb=8d65af789f3e2cf4cfbdbf71a0f7a61ebcd41d38;hpb=685f345708096ed21078aa44a6f4a6e6d1d1b580 diff --git a/mm/hugetlb.c b/mm/hugetlb.c index f10cc27..6f048fc 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1031,6 +1031,7 @@ int __weak alloc_bootmem_huge_page(struct hstate *h) NODE_DATA(h->next_nid_to_alloc), huge_page_size(h), huge_page_size(h), 0); + hstate_next_node_to_alloc(h); if (addr) { /* * Use the beginning of the huge page to store the @@ -1040,7 +1041,6 @@ int __weak alloc_bootmem_huge_page(struct hstate *h) m = addr; goto found; } - hstate_next_node_to_alloc(h); nr_nodes--; } return 0; @@ -1537,7 +1537,7 @@ static unsigned int cpuset_mems_nr(unsigned int *array) #ifdef CONFIG_SYSCTL int hugetlb_sysctl_handler(struct ctl_table *table, int write, - struct file *file, void __user *buffer, + void __user *buffer, size_t *length, loff_t *ppos) { struct hstate *h = &default_hstate; @@ -1548,7 +1548,7 @@ int hugetlb_sysctl_handler(struct ctl_table *table, int write, table->data = &tmp; table->maxlen = sizeof(unsigned long); - proc_doulongvec_minmax(table, write, file, buffer, length, ppos); + proc_doulongvec_minmax(table, write, buffer, length, ppos); if (write) h->max_huge_pages = set_max_huge_pages(h, tmp); @@ -1557,10 +1557,10 @@ int hugetlb_sysctl_handler(struct ctl_table *table, int write, } int hugetlb_treat_movable_handler(struct ctl_table *table, int write, - struct file *file, void __user *buffer, + void __user *buffer, size_t *length, loff_t *ppos) { - proc_dointvec(table, write, file, buffer, length, ppos); + proc_dointvec(table, write, buffer, length, ppos); if (hugepages_treat_as_movable) htlb_alloc_mask = GFP_HIGHUSER_MOVABLE; else @@ -1569,7 +1569,7 @@ int hugetlb_treat_movable_handler(struct ctl_table *table, int write, } int hugetlb_overcommit_handler(struct ctl_table *table, int write, - struct file *file, void __user *buffer, + void __user *buffer, size_t *length, loff_t *ppos) { struct hstate *h = &default_hstate; @@ -1580,7 +1580,7 @@ int hugetlb_overcommit_handler(struct ctl_table *table, int write, table->data = &tmp; table->maxlen = sizeof(unsigned long); - proc_doulongvec_minmax(table, write, file, buffer, length, ppos); + proc_doulongvec_minmax(table, write, buffer, length, ppos); if (write) { spin_lock(&hugetlb_lock); @@ -2016,6 +2016,26 @@ static struct page *hugetlbfs_pagecache_page(struct hstate *h, return find_lock_page(mapping, idx); } +/* + * Return whether there is a pagecache page to back given address within VMA. + * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. + */ +static bool hugetlbfs_pagecache_present(struct hstate *h, + struct vm_area_struct *vma, unsigned long address) +{ + struct address_space *mapping; + pgoff_t idx; + struct page *page; + + mapping = vma->vm_file->f_mapping; + idx = vma_hugecache_offset(h, vma, address); + + page = find_get_page(mapping, idx); + if (page) + put_page(page); + return page != NULL; +} + static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, pte_t *ptep, unsigned int flags) { @@ -2211,54 +2231,55 @@ follow_huge_pud(struct mm_struct *mm, unsigned long address, return NULL; } -static int huge_zeropage_ok(pte_t *ptep, int write, int shared) -{ - if (!ptep || write || shared) - return 0; - else - return huge_pte_none(huge_ptep_get(ptep)); -} - int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, struct page **pages, struct vm_area_struct **vmas, unsigned long *position, int *length, int i, - int write) + unsigned int flags) { unsigned long pfn_offset; unsigned long vaddr = *position; int remainder = *length; struct hstate *h = hstate_vma(vma); - int zeropage_ok = 0; - int shared = vma->vm_flags & VM_SHARED; spin_lock(&mm->page_table_lock); while (vaddr < vma->vm_end && remainder) { pte_t *pte; + int absent; struct page *page; /* * Some archs (sparc64, sh*) have multiple pte_ts to - * each hugepage. We have to make * sure we get the + * each hugepage. We have to make sure we get the * first, for the page indexing below to work. */ pte = huge_pte_offset(mm, vaddr & huge_page_mask(h)); - if (huge_zeropage_ok(pte, write, shared)) - zeropage_ok = 1; + absent = !pte || huge_pte_none(huge_ptep_get(pte)); + + /* + * When coredumping, it suits get_dump_page if we just return + * an error where there's an empty slot with no huge pagecache + * to back it. This way, we avoid allocating a hugepage, and + * the sparse dumpfile avoids allocating disk blocks, but its + * huge holes still show up with zeroes where they need to be. + */ + if (absent && (flags & FOLL_DUMP) && + !hugetlbfs_pagecache_present(h, vma, vaddr)) { + remainder = 0; + break; + } - if (!pte || - (huge_pte_none(huge_ptep_get(pte)) && !zeropage_ok) || - (write && !pte_write(huge_ptep_get(pte)))) { + if (absent || + ((flags & FOLL_WRITE) && !pte_write(huge_ptep_get(pte)))) { int ret; spin_unlock(&mm->page_table_lock); - ret = hugetlb_fault(mm, vma, vaddr, write); + ret = hugetlb_fault(mm, vma, vaddr, + (flags & FOLL_WRITE) ? FAULT_FLAG_WRITE : 0); spin_lock(&mm->page_table_lock); if (!(ret & VM_FAULT_ERROR)) continue; remainder = 0; - if (!i) - i = -EFAULT; break; } @@ -2266,10 +2287,7 @@ int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, page = pte_page(huge_ptep_get(pte)); same_page: if (pages) { - if (zeropage_ok) - pages[i] = ZERO_PAGE(0); - else - pages[i] = mem_map_offset(page, pfn_offset); + pages[i] = mem_map_offset(page, pfn_offset); get_page(pages[i]); } @@ -2293,7 +2311,7 @@ same_page: *length = remainder; *position = vaddr; - return i; + return i ? i : -EFAULT; } void hugetlb_change_protection(struct vm_area_struct *vma,