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Diffstat (limited to 'mm')
-rw-r--r--mm/hugetlb.c111
-rw-r--r--mm/migrate.c3
2 files changed, 96 insertions, 18 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 360765156c7c..f260ffa26363 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -34,6 +34,7 @@
 #include <linux/hugetlb_cgroup.h>
 #include <linux/node.h>
 #include <linux/userfaultfd_k.h>
+#include <linux/page_owner.h>
 #include "internal.h"
 
 int hugetlb_max_hstate __read_mostly;
@@ -1219,6 +1220,28 @@ static void clear_page_huge_active(struct page *page)
 	ClearPagePrivate(&page[1]);
 }
 
+/*
+ * Internal hugetlb specific page flag. Do not use outside of the hugetlb
+ * code
+ */
+static inline bool PageHugeTemporary(struct page *page)
+{
+	if (!PageHuge(page))
+		return false;
+
+	return (unsigned long)page[2].mapping == -1U;
+}
+
+static inline void SetPageHugeTemporary(struct page *page)
+{
+	page[2].mapping = (void *)-1U;
+}
+
+static inline void ClearPageHugeTemporary(struct page *page)
+{
+	page[2].mapping = NULL;
+}
+
 void free_huge_page(struct page *page)
 {
 	/*
@@ -1253,7 +1276,11 @@ void free_huge_page(struct page *page)
 	if (restore_reserve)
 		h->resv_huge_pages++;
 
-	if (h->surplus_huge_pages_node[nid]) {
+	if (PageHugeTemporary(page)) {
+		list_del(&page->lru);
+		ClearPageHugeTemporary(page);
+		update_and_free_page(h, page);
+	} else if (h->surplus_huge_pages_node[nid]) {
 		/* remove the page from active list */
 		list_del(&page->lru);
 		update_and_free_page(h, page);
@@ -1507,7 +1534,10 @@ int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn)
 	return rc;
 }
 
-static struct page *__alloc_buddy_huge_page(struct hstate *h, gfp_t gfp_mask,
+/*
+ * Allocates a fresh surplus page from the page allocator.
+ */
+static struct page *__alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask,
 		int nid, nodemask_t *nmask)
 {
 	struct page *page;
@@ -1571,6 +1601,28 @@ static struct page *__alloc_buddy_huge_page(struct hstate *h, gfp_t gfp_mask,
 	return page;
 }
 
+static struct page *__alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask,
+		int nid, nodemask_t *nmask)
+{
+	struct page *page;
+
+	if (hstate_is_gigantic(h))
+		return NULL;
+
+	page = __hugetlb_alloc_buddy_huge_page(h, gfp_mask, nid, nmask);
+	if (!page)
+		return NULL;
+
+	/*
+	 * We do not account these pages as surplus because they are only
+	 * temporary and will be released properly on the last reference
+	 */
+	prep_new_huge_page(h, page, page_to_nid(page));
+	SetPageHugeTemporary(page);
+
+	return page;
+}
+
 /*
  * Use the VMA's mpolicy to allocate a huge page from the buddy.
  */
@@ -1585,17 +1637,13 @@ struct page *__alloc_buddy_huge_page_with_mpol(struct hstate *h,
 	nodemask_t *nodemask;
 
 	nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask);
-	page = __alloc_buddy_huge_page(h, gfp_mask, nid, nodemask);
+	page = __alloc_surplus_huge_page(h, gfp_mask, nid, nodemask);
 	mpol_cond_put(mpol);
 
 	return page;
 }
 
-/*
- * This allocation function is useful in the context where vma is irrelevant.
- * E.g. soft-offlining uses this function because it only cares physical
- * address of error page.
- */
+/* page migration callback function */
 struct page *alloc_huge_page_node(struct hstate *h, int nid)
 {
 	gfp_t gfp_mask = htlb_alloc_mask(h);
@@ -1610,12 +1658,12 @@ struct page *alloc_huge_page_node(struct hstate *h, int nid)
 	spin_unlock(&hugetlb_lock);
 
 	if (!page)
-		page = __alloc_buddy_huge_page(h, gfp_mask, nid, NULL);
+		page = __alloc_migrate_huge_page(h, gfp_mask, nid, NULL);
 
 	return page;
 }
 
-
+/* page migration callback function */
 struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid,
 		nodemask_t *nmask)
 {
@@ -1633,9 +1681,7 @@ struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid,
 	}
 	spin_unlock(&hugetlb_lock);
 
-	/* No reservations, try to overcommit */
-
-	return __alloc_buddy_huge_page(h, gfp_mask, preferred_nid, nmask);
+	return __alloc_migrate_huge_page(h, gfp_mask, preferred_nid, nmask);
 }
 
 /*
@@ -1663,7 +1709,7 @@ static int gather_surplus_pages(struct hstate *h, int delta)
 retry:
 	spin_unlock(&hugetlb_lock);
 	for (i = 0; i < needed; i++) {
-		page = __alloc_buddy_huge_page(h, htlb_alloc_mask(h),
+		page = __alloc_surplus_huge_page(h, htlb_alloc_mask(h),
 				NUMA_NO_NODE, NULL);
 		if (!page) {
 			alloc_ok = false;
@@ -2260,7 +2306,7 @@ static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count,
 	 * First take pages out of surplus state.  Then make up the
 	 * remaining difference by allocating fresh huge pages.
 	 *
-	 * We might race with __alloc_buddy_huge_page() here and be unable
+	 * We might race with __alloc_surplus_huge_page() here and be unable
 	 * to convert a surplus huge page to a normal huge page. That is
 	 * not critical, though, it just means the overall size of the
 	 * pool might be one hugepage larger than it needs to be, but
@@ -2303,7 +2349,7 @@ static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count,
 	 * By placing pages into the surplus state independent of the
 	 * overcommit value, we are allowing the surplus pool size to
 	 * exceed overcommit. There are few sane options here. Since
-	 * __alloc_buddy_huge_page() is checking the global counter,
+	 * __alloc_surplus_huge_page() is checking the global counter,
 	 * though, we'll note that we're not allowed to exceed surplus
 	 * and won't grow the pool anywhere else. Not until one of the
 	 * sysctls are changed, or the surplus pages go out of use.
@@ -4779,3 +4825,36 @@ void putback_active_hugepage(struct page *page)
 	spin_unlock(&hugetlb_lock);
 	put_page(page);
 }
+
+void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason)
+{
+	struct hstate *h = page_hstate(oldpage);
+
+	hugetlb_cgroup_migrate(oldpage, newpage);
+	set_page_owner_migrate_reason(newpage, reason);
+
+	/*
+	 * transfer temporary state of the new huge page. This is
+	 * reverse to other transitions because the newpage is going to
+	 * be final while the old one will be freed so it takes over
+	 * the temporary status.
+	 *
+	 * Also note that we have to transfer the per-node surplus state
+	 * here as well otherwise the global surplus count will not match
+	 * the per-node's.
+	 */
+	if (PageHugeTemporary(newpage)) {
+		int old_nid = page_to_nid(oldpage);
+		int new_nid = page_to_nid(newpage);
+
+		SetPageHugeTemporary(oldpage);
+		ClearPageHugeTemporary(newpage);
+
+		spin_lock(&hugetlb_lock);
+		if (h->surplus_huge_pages_node[old_nid]) {
+			h->surplus_huge_pages_node[old_nid]--;
+			h->surplus_huge_pages_node[new_nid]++;
+		}
+		spin_unlock(&hugetlb_lock);
+	}
+}
diff --git a/mm/migrate.c b/mm/migrate.c
index 4d0be47a322a..1e5525a25691 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1323,9 +1323,8 @@ put_anon:
 		put_anon_vma(anon_vma);
 
 	if (rc == MIGRATEPAGE_SUCCESS) {
-		hugetlb_cgroup_migrate(hpage, new_hpage);
+		move_hugetlb_state(hpage, new_hpage, reason);
 		put_new_page = NULL;
-		set_page_owner_migrate_reason(new_hpage, reason);
 	}
 
 	unlock_page(hpage);