X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Fhugetlb.c;h=dcacc811e70ede9cda49d4d2cf56a6d5d5404a56;hb=348e1e04b5229a481891699ce86da009b793f29e;hp=d9a380312467d7d13f70064c50b6c718e38f55a6;hpb=03054de1e0b90b33e9974107d84dabd2509f5898;p=pandora-kernel.git

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index d9a380312467..dcacc811e70e 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -24,14 +24,15 @@
 const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL;
 static unsigned long nr_huge_pages, free_huge_pages, resv_huge_pages;
 static unsigned long surplus_huge_pages;
+static unsigned long nr_overcommit_huge_pages;
 unsigned long max_huge_pages;
+unsigned long sysctl_overcommit_huge_pages;
 static struct list_head hugepage_freelists[MAX_NUMNODES];
 static unsigned int nr_huge_pages_node[MAX_NUMNODES];
 static unsigned int free_huge_pages_node[MAX_NUMNODES];
 static unsigned int surplus_huge_pages_node[MAX_NUMNODES];
 static gfp_t htlb_alloc_mask = GFP_HIGHUSER;
 unsigned long hugepages_treat_as_movable;
-unsigned long nr_overcommit_huge_pages;
 static int hugetlb_next_nid;
 
 /*
@@ -70,7 +71,25 @@ static void enqueue_huge_page(struct page *page)
 	free_huge_pages_node[nid]++;
 }
 
-static struct page *dequeue_huge_page(struct vm_area_struct *vma,
+static struct page *dequeue_huge_page(void)
+{
+	int nid;
+	struct page *page = NULL;
+
+	for (nid = 0; nid < MAX_NUMNODES; ++nid) {
+		if (!list_empty(&hugepage_freelists[nid])) {
+			page = list_entry(hugepage_freelists[nid].next,
+					  struct page, lru);
+			list_del(&page->lru);
+			free_huge_pages--;
+			free_huge_pages_node[nid]--;
+			break;
+		}
+	}
+	return page;
+}
+
+static struct page *dequeue_huge_page_vma(struct vm_area_struct *vma,
 				unsigned long address)
 {
 	int nid;
@@ -119,6 +138,7 @@ static void free_huge_page(struct page *page)
 	struct address_space *mapping;
 
 	mapping = (struct address_space *) page_private(page);
+	set_page_private(page, 0);
 	BUG_ON(page_count(page));
 	INIT_LIST_HEAD(&page->lru);
 
@@ -133,7 +153,6 @@ static void free_huge_page(struct page *page)
 	spin_unlock(&hugetlb_lock);
 	if (mapping)
 		hugetlb_put_quota(mapping, 1);
-	set_page_private(page, 0);
 }
 
 /*
@@ -295,8 +314,10 @@ static int gather_surplus_pages(int delta)
 	int needed, allocated;
 
 	needed = (resv_huge_pages + delta) - free_huge_pages;
-	if (needed <= 0)
+	if (needed <= 0) {
+		resv_huge_pages += delta;
 		return 0;
+	}
 
 	allocated = 0;
 	INIT_LIST_HEAD(&surplus_list);
@@ -334,9 +355,12 @@ retry:
 	 * The surplus_list now contains _at_least_ the number of extra pages
 	 * needed to accomodate the reservation.  Add the appropriate number
 	 * of pages to the hugetlb pool and free the extras back to the buddy
-	 * allocator.
+	 * allocator.  Commit the entire reservation here to prevent another
+	 * process from stealing the pages as they are added to the pool but
+	 * before they are reserved.
 	 */
 	needed += allocated;
+	resv_huge_pages += delta;
 	ret = 0;
 free:
 	list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
@@ -370,6 +394,9 @@ static void return_unused_surplus_pages(unsigned long unused_resv_pages)
 	struct page *page;
 	unsigned long nr_pages;
 
+	/* Uncommit the reservation */
+	resv_huge_pages -= unused_resv_pages;
+
 	nr_pages = min(unused_resv_pages, surplus_huge_pages);
 
 	while (nr_pages) {
@@ -401,7 +428,7 @@ static struct page *alloc_huge_page_shared(struct vm_area_struct *vma,
 	struct page *page;
 
 	spin_lock(&hugetlb_lock);
-	page = dequeue_huge_page(vma, addr);
+	page = dequeue_huge_page_vma(vma, addr);
 	spin_unlock(&hugetlb_lock);
 	return page ? page : ERR_PTR(-VM_FAULT_OOM);
 }
@@ -416,7 +443,7 @@ static struct page *alloc_huge_page_private(struct vm_area_struct *vma,
 
 	spin_lock(&hugetlb_lock);
 	if (free_huge_pages > resv_huge_pages)
-		page = dequeue_huge_page(vma, addr);
+		page = dequeue_huge_page_vma(vma, addr);
 	spin_unlock(&hugetlb_lock);
 	if (!page) {
 		page = alloc_buddy_huge_page(vma, addr);
@@ -569,7 +596,7 @@ static unsigned long set_max_huge_pages(unsigned long count)
 	min_count = max(count, min_count);
 	try_to_free_low(min_count);
 	while (min_count < persistent_huge_pages) {
-		struct page *page = dequeue_huge_page(NULL, 0);
+		struct page *page = dequeue_huge_page();
 		if (!page)
 			break;
 		update_and_free_page(page);
@@ -609,8 +636,9 @@ int hugetlb_overcommit_handler(struct ctl_table *table, int write,
 			struct file *file, void __user *buffer,
 			size_t *length, loff_t *ppos)
 {
-	spin_lock(&hugetlb_lock);
 	proc_doulongvec_minmax(table, write, file, buffer, length, ppos);
+	spin_lock(&hugetlb_lock);
+	nr_overcommit_huge_pages = sysctl_overcommit_huge_pages;
 	spin_unlock(&hugetlb_lock);
 	return 0;
 }
@@ -1203,12 +1231,13 @@ static int hugetlb_acct_memory(long delta)
 		if (gather_surplus_pages(delta) < 0)
 			goto out;
 
-		if (delta > cpuset_mems_nr(free_huge_pages_node))
+		if (delta > cpuset_mems_nr(free_huge_pages_node)) {
+			return_unused_surplus_pages(delta);
 			goto out;
+		}
 	}
 
 	ret = 0;
-	resv_huge_pages += delta;
 	if (delta < 0)
 		return_unused_surplus_pages((unsigned long) -delta);