diff options
| -rw-r--r-- | mm/hugetlb.c | 58 |
1 files changed, 53 insertions, 5 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 05bc9af..72acbb2 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -247,6 +247,9 @@ static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag) /* Decrement the reserved pages in the hugepage pool by one */ static void decrement_hugepage_resv_vma(struct vm_area_struct *vma) { + if (vma->vm_flags & VM_NORESERVE) + return; + if (vma->vm_flags & VM_SHARED) { /* Shared mappings always use reserves */ resv_huge_pages--; @@ -720,25 +723,65 @@ static void return_unused_surplus_pages(unsigned long unused_resv_pages) } } +/* + * Determine if the huge page at addr within the vma has an associated + * reservation. Where it does not we will need to logically increase + * reservation and actually increase quota before an allocation can occur. + * Where any new reservation would be required the reservation change is + * prepared, but not committed. Once the page has been quota'd allocated + * an instantiated the change should be committed via vma_commit_reservation. + * No action is required on failure. + */ +static int vma_needs_reservation(struct vm_area_struct *vma, unsigned long addr) +{ + struct address_space *mapping = vma->vm_file->f_mapping; + struct inode *inode = mapping->host; + + if (vma->vm_flags & VM_SHARED) { + pgoff_t idx = vma_pagecache_offset(vma, addr); + return region_chg(&inode->i_mapping->private_list, + idx, idx + 1); + + } else { + if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) + return 1; + } + + return 0; +} +static void vma_commit_reservation(struct vm_area_struct *vma, + unsigned long addr) +{ + struct address_space *mapping = vma->vm_file->f_mapping; + struct inode *inode = mapping->host; + + if (vma->vm_flags & VM_SHARED) { + pgoff_t idx = vma_pagecache_offset(vma, addr); + region_add(&inode->i_mapping->private_list, idx, idx + 1); + } +} + static struct page *alloc_huge_page(struct vm_area_struct *vma, unsigned long addr, int avoid_reserve) { struct page *page; struct address_space *mapping = vma->vm_file->f_mapping; struct inode *inode = mapping->host; - unsigned int chg = 0; + unsigned int chg; /* * Processes that did not create the mapping will have no reserves and * will not have accounted against quota. Check that the quota can be * made before satisfying the allocation + * MAP_NORESERVE mappings may also need pages and quota allocated + * if no reserve mapping overlaps. */ - if (!(vma->vm_flags & VM_SHARED) && - !is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { - chg = 1; + chg = vma_needs_reservation(vma, addr); + if (chg < 0) + return ERR_PTR(chg); + if (chg) if (hugetlb_get_quota(inode->i_mapping, chg)) return ERR_PTR(-ENOSPC); - } spin_lock(&hugetlb_lock); page = dequeue_huge_page_vma(vma, addr, avoid_reserve); @@ -755,6 +798,8 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma, set_page_refcounted(page); set_page_private(page, (unsigned long) mapping); + vma_commit_reservation(vma, addr); + return page; } @@ -1560,6 +1605,9 @@ int hugetlb_reserve_pages(struct inode *inode, { long ret, chg; + if (vma && vma->vm_flags & VM_NORESERVE) + return 0; + /* * Shared mappings base their reservation on the number of pages that * are already allocated on behalf of the file. Private mappings need |
