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-rw-r--r--mm/hugetlb.c135
1 files changed, 108 insertions, 27 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index b1c314877334..afa057a1d3fe 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -53,6 +53,84 @@ static unsigned long __initdata default_hstate_size;
*/
static DEFINE_SPINLOCK(hugetlb_lock);
+static inline void unlock_or_release_subpool(struct hugepage_subpool *spool)
+{
+ bool free = (spool->count == 0) && (spool->used_hpages == 0);
+
+ spin_unlock(&spool->lock);
+
+ /* If no pages are used, and no other handles to the subpool
+ * remain, free the subpool the subpool remain */
+ if (free)
+ kfree(spool);
+}
+
+struct hugepage_subpool *hugepage_new_subpool(long nr_blocks)
+{
+ struct hugepage_subpool *spool;
+
+ spool = kmalloc(sizeof(*spool), GFP_KERNEL);
+ if (!spool)
+ return NULL;
+
+ spin_lock_init(&spool->lock);
+ spool->count = 1;
+ spool->max_hpages = nr_blocks;
+ spool->used_hpages = 0;
+
+ return spool;
+}
+
+void hugepage_put_subpool(struct hugepage_subpool *spool)
+{
+ spin_lock(&spool->lock);
+ BUG_ON(!spool->count);
+ spool->count--;
+ unlock_or_release_subpool(spool);
+}
+
+static int hugepage_subpool_get_pages(struct hugepage_subpool *spool,
+ long delta)
+{
+ int ret = 0;
+
+ if (!spool)
+ return 0;
+
+ spin_lock(&spool->lock);
+ if ((spool->used_hpages + delta) <= spool->max_hpages) {
+ spool->used_hpages += delta;
+ } else {
+ ret = -ENOMEM;
+ }
+ spin_unlock(&spool->lock);
+
+ return ret;
+}
+
+static void hugepage_subpool_put_pages(struct hugepage_subpool *spool,
+ long delta)
+{
+ if (!spool)
+ return;
+
+ spin_lock(&spool->lock);
+ spool->used_hpages -= delta;
+ /* If hugetlbfs_put_super couldn't free spool due to
+ * an outstanding quota reference, free it now. */
+ unlock_or_release_subpool(spool);
+}
+
+static inline struct hugepage_subpool *subpool_inode(struct inode *inode)
+{
+ return HUGETLBFS_SB(inode->i_sb)->spool;
+}
+
+static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma)
+{
+ return subpool_inode(vma->vm_file->f_dentry->d_inode);
+}
+
/*
* Region tracking -- allows tracking of reservations and instantiated pages
* across the pages in a mapping.
@@ -540,9 +618,9 @@ static void free_huge_page(struct page *page)
*/
struct hstate *h = page_hstate(page);
int nid = page_to_nid(page);
- struct address_space *mapping;
+ struct hugepage_subpool *spool =
+ (struct hugepage_subpool *)page_private(page);
- mapping = (struct address_space *) page_private(page);
set_page_private(page, 0);
page->mapping = NULL;
BUG_ON(page_count(page));
@@ -558,8 +636,7 @@ static void free_huge_page(struct page *page)
enqueue_huge_page(h, page);
}
spin_unlock(&hugetlb_lock);
- if (mapping)
- hugetlb_put_quota(mapping, 1);
+ hugepage_subpool_put_pages(spool, 1);
}
static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
@@ -977,11 +1054,12 @@ static void return_unused_surplus_pages(struct hstate *h,
/*
* 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.
+ * reservation and actually increase subpool usage 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 allocated from the subpool and instantiated the change should
+ * be committed via vma_commit_reservation. No action is required on
+ * failure.
*/
static long vma_needs_reservation(struct hstate *h,
struct vm_area_struct *vma, unsigned long addr)
@@ -1030,24 +1108,24 @@ static void vma_commit_reservation(struct hstate *h,
static struct page *alloc_huge_page(struct vm_area_struct *vma,
unsigned long addr, int avoid_reserve)
{
+ struct hugepage_subpool *spool = subpool_vma(vma);
struct hstate *h = hstate_vma(vma);
struct page *page;
- struct address_space *mapping = vma->vm_file->f_mapping;
- struct inode *inode = mapping->host;
long 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.
+ * Processes that did not create the mapping will have no
+ * reserves and will not have accounted against subpool
+ * limit. Check that the subpool limit can be made before
+ * satisfying the allocation MAP_NORESERVE mappings may also
+ * need pages and subpool limit allocated allocated if no reserve
+ * mapping overlaps.
*/
chg = vma_needs_reservation(h, vma, addr);
if (chg < 0)
return ERR_PTR(-VM_FAULT_OOM);
if (chg)
- if (hugetlb_get_quota(inode->i_mapping, chg))
+ if (hugepage_subpool_get_pages(spool, chg))
return ERR_PTR(-VM_FAULT_SIGBUS);
spin_lock(&hugetlb_lock);
@@ -1057,12 +1135,12 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
if (!page) {
page = alloc_buddy_huge_page(h, NUMA_NO_NODE);
if (!page) {
- hugetlb_put_quota(inode->i_mapping, chg);
+ hugepage_subpool_put_pages(spool, chg);
return ERR_PTR(-VM_FAULT_SIGBUS);
}
}
- set_page_private(page, (unsigned long) mapping);
+ set_page_private(page, (unsigned long)spool);
vma_commit_reservation(h, vma, addr);
@@ -2083,6 +2161,7 @@ static void hugetlb_vm_op_close(struct vm_area_struct *vma)
{
struct hstate *h = hstate_vma(vma);
struct resv_map *reservations = vma_resv_map(vma);
+ struct hugepage_subpool *spool = subpool_vma(vma);
unsigned long reserve;
unsigned long start;
unsigned long end;
@@ -2098,7 +2177,7 @@ static void hugetlb_vm_op_close(struct vm_area_struct *vma)
if (reserve) {
hugetlb_acct_memory(h, -reserve);
- hugetlb_put_quota(vma->vm_file->f_mapping, reserve);
+ hugepage_subpool_put_pages(spool, reserve);
}
}
}
@@ -2331,7 +2410,7 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
*/
address = address & huge_page_mask(h);
pgoff = vma_hugecache_offset(h, vma, address);
- mapping = (struct address_space *)page_private(page);
+ mapping = vma->vm_file->f_dentry->d_inode->i_mapping;
/*
* Take the mapping lock for the duration of the table walk. As
@@ -2884,11 +2963,12 @@ int hugetlb_reserve_pages(struct inode *inode,
{
long ret, chg;
struct hstate *h = hstate_inode(inode);
+ struct hugepage_subpool *spool = subpool_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
+ * without using reserves
*/
if (vm_flags & VM_NORESERVE)
return 0;
@@ -2915,17 +2995,17 @@ int hugetlb_reserve_pages(struct inode *inode,
if (chg < 0)
return chg;
- /* There must be enough filesystem quota for the mapping */
- if (hugetlb_get_quota(inode->i_mapping, chg))
+ /* There must be enough pages in the subpool for the mapping */
+ if (hugepage_subpool_get_pages(spool, chg))
return -ENOSPC;
/*
* Check enough hugepages are available for the reservation.
- * Hand back the quota if there are not
+ * Hand the pages back to the subpool if there are not
*/
ret = hugetlb_acct_memory(h, chg);
if (ret < 0) {
- hugetlb_put_quota(inode->i_mapping, chg);
+ hugepage_subpool_put_pages(spool, chg);
return ret;
}
@@ -2949,12 +3029,13 @@ void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed)
{
struct hstate *h = hstate_inode(inode);
long chg = region_truncate(&inode->i_mapping->private_list, offset);
+ struct hugepage_subpool *spool = subpool_inode(inode);
spin_lock(&inode->i_lock);
inode->i_blocks -= (blocks_per_huge_page(h) * freed);
spin_unlock(&inode->i_lock);
- hugetlb_put_quota(inode->i_mapping, (chg - freed));
+ hugepage_subpool_put_pages(spool, (chg - freed));
hugetlb_acct_memory(h, -(chg - freed));
}