diff options
| -rw-r--r-- | mm/hugetlb.c | 53 |
1 files changed, 33 insertions, 20 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 207464209546..107da3d809a8 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2272,10 +2272,18 @@ int hugetlb_reserve_pages(struct inode *inode, struct vm_area_struct *vma, int acctflag) { - long ret = 0, chg; + long ret, chg; struct hstate *h = hstate_inode(inode); /* + * Only apply hugepage reservation if asked. At fault time, an + * attempt will be made for VM_NORESERVE to allocate a page + * and filesystem quota without using reserves + */ + if (acctflag & 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 * to reserve the full area even if read-only as mprotect() may be @@ -2283,42 +2291,47 @@ int hugetlb_reserve_pages(struct inode *inode, */ if (!vma || vma->vm_flags & VM_SHARED) chg = region_chg(&inode->i_mapping->private_list, from, to); - else + else { + struct resv_map *resv_map = resv_map_alloc(); + if (!resv_map) + return -ENOMEM; + chg = to - from; + set_vma_resv_map(vma, resv_map); + set_vma_resv_flags(vma, HPAGE_RESV_OWNER); + } + if (chg < 0) return chg; + /* There must be enough filesystem quota for the mapping */ if (hugetlb_get_quota(inode->i_mapping, chg)) return -ENOSPC; /* - * Only apply hugepage reservation if asked. We still have to - * take the filesystem quota because it is an upper limit - * defined for the mount and not necessarily memory as a whole + * Check enough hugepages are available for the reservation. + * Hand back the quota if there are not */ - if (acctflag & VM_NORESERVE) { - reset_vma_resv_huge_pages(vma); - return 0; - } - ret = hugetlb_acct_memory(h, chg); if (ret < 0) { hugetlb_put_quota(inode->i_mapping, chg); return ret; } + + /* + * Account for the reservations made. Shared mappings record regions + * that have reservations as they are shared by multiple VMAs. + * When the last VMA disappears, the region map says how much + * the reservation was and the page cache tells how much of + * the reservation was consumed. Private mappings are per-VMA and + * only the consumed reservations are tracked. When the VMA + * disappears, the original reservation is the VMA size and the + * consumed reservations are stored in the map. Hence, nothing + * else has to be done for private mappings here + */ if (!vma || vma->vm_flags & VM_SHARED) region_add(&inode->i_mapping->private_list, from, to); - else { - struct resv_map *resv_map = resv_map_alloc(); - - if (!resv_map) - return -ENOMEM; - - set_vma_resv_map(vma, resv_map); - set_vma_resv_flags(vma, HPAGE_RESV_OWNER); - } - return 0; } |