static struct resv_map *vma_resv_map(struct vm_area_struct *vma)
{
VM_BUG_ON(!is_vm_hugetlb_page(vma));
- if (!(vma->vm_flags & VM_SHARED))
+ if (!(vma->vm_flags & VM_MAYSHARE))
return (struct resv_map *)(get_vma_private_data(vma) &
~HPAGE_RESV_MASK);
return NULL;
static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map)
{
VM_BUG_ON(!is_vm_hugetlb_page(vma));
- VM_BUG_ON(vma->vm_flags & VM_SHARED);
+ VM_BUG_ON(vma->vm_flags & VM_MAYSHARE);
set_vma_private_data(vma, (get_vma_private_data(vma) &
HPAGE_RESV_MASK) | (unsigned long)map);
static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags)
{
VM_BUG_ON(!is_vm_hugetlb_page(vma));
- VM_BUG_ON(vma->vm_flags & VM_SHARED);
+ VM_BUG_ON(vma->vm_flags & VM_MAYSHARE);
set_vma_private_data(vma, get_vma_private_data(vma) | flags);
}
if (vma->vm_flags & VM_NORESERVE)
return;
- if (vma->vm_flags & VM_SHARED) {
+ if (vma->vm_flags & VM_MAYSHARE) {
/* Shared mappings always use reserves */
h->resv_huge_pages--;
} else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
{
VM_BUG_ON(!is_vm_hugetlb_page(vma));
- if (!(vma->vm_flags & VM_SHARED))
+ if (!(vma->vm_flags & VM_MAYSHARE))
vma->vm_private_data = (void *)0;
}
/* Returns true if the VMA has associated reserve pages */
static int vma_has_reserves(struct vm_area_struct *vma)
{
- if (vma->vm_flags & VM_SHARED)
+ if (vma->vm_flags & VM_MAYSHARE)
return 1;
if (is_vma_resv_set(vma, HPAGE_RESV_OWNER))
return 1;
* an instantiated the change should be committed via vma_commit_reservation.
* No action is required on failure.
*/
-static int vma_needs_reservation(struct hstate *h,
+static long vma_needs_reservation(struct hstate *h,
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) {
+ if (vma->vm_flags & VM_MAYSHARE) {
pgoff_t idx = vma_hugecache_offset(h, vma, addr);
return region_chg(&inode->i_mapping->private_list,
idx, idx + 1);
return 1;
} else {
- int err;
+ long err;
pgoff_t idx = vma_hugecache_offset(h, vma, addr);
struct resv_map *reservations = vma_resv_map(vma);
struct address_space *mapping = vma->vm_file->f_mapping;
struct inode *inode = mapping->host;
- if (vma->vm_flags & VM_SHARED) {
+ if (vma->vm_flags & VM_MAYSHARE) {
pgoff_t idx = vma_hugecache_offset(h, vma, addr);
region_add(&inode->i_mapping->private_list, idx, idx + 1);
struct page *page;
struct address_space *mapping = vma->vm_file->f_mapping;
struct inode *inode = mapping->host;
- unsigned int chg;
+ long chg;
/*
* Processes that did not create the mapping will have no reserves and
* at the time of fork() could consume its reserves on COW instead
* of the full address range.
*/
- if (!(vma->vm_flags & VM_SHARED) &&
+ if (!(vma->vm_flags & VM_MAYSHARE) &&
is_vma_resv_set(vma, HPAGE_RESV_OWNER) &&
old_page != pagecache_page)
outside_reserve = 1;
clear_huge_page(page, address, huge_page_size(h));
__SetPageUptodate(page);
- if (vma->vm_flags & VM_SHARED) {
+ if (vma->vm_flags & VM_MAYSHARE) {
int err;
struct inode *inode = mapping->host;
goto out_mutex;
}
- if (!(vma->vm_flags & VM_SHARED))
+ if (!(vma->vm_flags & VM_MAYSHARE))
pagecache_page = hugetlbfs_pagecache_page(h,
vma, address);
}
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
* called to make the mapping read-write. Assume !vma is a shm mapping
*/
- if (!vma || vma->vm_flags & VM_SHARED)
+ if (!vma || vma->vm_flags & VM_MAYSHARE)
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;
}
- 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);
- }
+ /*
+ * 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_MAYSHARE)
+ region_add(&inode->i_mapping->private_list, from, to);
return 0;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff