1 files changed, 311 insertions, 54 deletions

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 6ba4aab2db0b..bf91dc9e7a79 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -60,7 +60,7 @@ atomic_long_t nr_swap_pages;
 EXPORT_SYMBOL_GPL(nr_swap_pages);
 /* protected with swap_lock. reading in vm_swap_full() doesn't need lock */
 long total_swap_pages;
-static int least_priority;
+static int least_priority = -1;
 
 static const char Bad_file[] = "Bad swap file entry ";
 static const char Unused_file[] = "Unused swap file entry ";
@@ -85,7 +85,7 @@ PLIST_HEAD(swap_active_head);
  * is held and the locking order requires swap_lock to be taken
  * before any swap_info_struct->lock.
  */
-static PLIST_HEAD(swap_avail_head);
+struct plist_head *swap_avail_heads;
 static DEFINE_SPINLOCK(swap_avail_lock);
 
 struct swap_info_struct *swap_info[MAX_SWAPFILES];
@@ -96,6 +96,8 @@ static DECLARE_WAIT_QUEUE_HEAD(proc_poll_wait);
 /* Activity counter to indicate that a swapon or swapoff has occurred */
 static atomic_t proc_poll_event = ATOMIC_INIT(0);
 
+atomic_t nr_rotate_swap = ATOMIC_INIT(0);
+
 static inline unsigned char swap_count(unsigned char ent)
 {
 	return ent & ~SWAP_HAS_CACHE;	/* may include SWAP_HAS_CONT flag */
@@ -265,6 +267,16 @@ static inline void cluster_set_null(struct swap_cluster_info *info)
 	info->data = 0;
 }
 
+static inline bool cluster_is_huge(struct swap_cluster_info *info)
+{
+	return info->flags & CLUSTER_FLAG_HUGE;
+}
+
+static inline void cluster_clear_huge(struct swap_cluster_info *info)
+{
+	info->flags &= ~CLUSTER_FLAG_HUGE;
+}
+
 static inline struct swap_cluster_info *lock_cluster(struct swap_info_struct *si,
 						     unsigned long offset)
 {
@@ -580,6 +592,21 @@ new_cluster:
 	return found_free;
 }
 
+static void __del_from_avail_list(struct swap_info_struct *p)
+{
+	int nid;
+
+	for_each_node(nid)
+		plist_del(&p->avail_lists[nid], &swap_avail_heads[nid]);
+}
+
+static void del_from_avail_list(struct swap_info_struct *p)
+{
+	spin_lock(&swap_avail_lock);
+	__del_from_avail_list(p);
+	spin_unlock(&swap_avail_lock);
+}
+
 static void swap_range_alloc(struct swap_info_struct *si, unsigned long offset,
 			     unsigned int nr_entries)
 {
@@ -593,10 +620,20 @@ static void swap_range_alloc(struct swap_info_struct *si, unsigned long offset,
 	if (si->inuse_pages == si->pages) {
 		si->lowest_bit = si->max;
 		si->highest_bit = 0;
-		spin_lock(&swap_avail_lock);
-		plist_del(&si->avail_list, &swap_avail_head);
-		spin_unlock(&swap_avail_lock);
+		del_from_avail_list(si);
+	}
+}
+
+static void add_to_avail_list(struct swap_info_struct *p)
+{
+	int nid;
+
+	spin_lock(&swap_avail_lock);
+	for_each_node(nid) {
+		WARN_ON(!plist_node_empty(&p->avail_lists[nid]));
+		plist_add(&p->avail_lists[nid], &swap_avail_heads[nid]);
 	}
+	spin_unlock(&swap_avail_lock);
 }
 
 static void swap_range_free(struct swap_info_struct *si, unsigned long offset,
@@ -611,13 +648,8 @@ static void swap_range_free(struct swap_info_struct *si, unsigned long offset,
 		bool was_full = !si->highest_bit;
 
 		si->highest_bit = end;
-		if (was_full && (si->flags & SWP_WRITEOK)) {
-			spin_lock(&swap_avail_lock);
-			WARN_ON(!plist_node_empty(&si->avail_list));
-			if (plist_node_empty(&si->avail_list))
-				plist_add(&si->avail_list, &swap_avail_head);
-			spin_unlock(&swap_avail_lock);
-		}
+		if (was_full && (si->flags & SWP_WRITEOK))
+			add_to_avail_list(si);
 	}
 	atomic_long_add(nr_entries, &nr_swap_pages);
 	si->inuse_pages -= nr_entries;
@@ -846,7 +878,7 @@ static int swap_alloc_cluster(struct swap_info_struct *si, swp_entry_t *slot)
 	offset = idx * SWAPFILE_CLUSTER;
 	ci = lock_cluster(si, offset);
 	alloc_cluster(si, idx);
-	cluster_set_count_flag(ci, SWAPFILE_CLUSTER, 0);
+	cluster_set_count_flag(ci, SWAPFILE_CLUSTER, CLUSTER_FLAG_HUGE);
 
 	map = si->swap_map + offset;
 	for (i = 0; i < SWAPFILE_CLUSTER; i++)
@@ -898,6 +930,7 @@ int get_swap_pages(int n_goal, bool cluster, swp_entry_t swp_entries[])
 	struct swap_info_struct *si, *next;
 	long avail_pgs;
 	int n_ret = 0;
+	int node;
 
 	/* Only single cluster request supported */
 	WARN_ON_ONCE(n_goal > 1 && cluster);
@@ -917,14 +950,15 @@ int get_swap_pages(int n_goal, bool cluster, swp_entry_t swp_entries[])
 	spin_lock(&swap_avail_lock);
 
 start_over:
-	plist_for_each_entry_safe(si, next, &swap_avail_head, avail_list) {
+	node = numa_node_id();
+	plist_for_each_entry_safe(si, next, &swap_avail_heads[node], avail_lists[node]) {
 		/* requeue si to after same-priority siblings */
-		plist_requeue(&si->avail_list, &swap_avail_head);
+		plist_requeue(&si->avail_lists[node], &swap_avail_heads[node]);
 		spin_unlock(&swap_avail_lock);
 		spin_lock(&si->lock);
 		if (!si->highest_bit || !(si->flags & SWP_WRITEOK)) {
 			spin_lock(&swap_avail_lock);
-			if (plist_node_empty(&si->avail_list)) {
+			if (plist_node_empty(&si->avail_lists[node])) {
 				spin_unlock(&si->lock);
 				goto nextsi;
 			}
@@ -934,13 +968,14 @@ start_over:
 			WARN(!(si->flags & SWP_WRITEOK),
 			     "swap_info %d in list but !SWP_WRITEOK\n",
 			     si->type);
-			plist_del(&si->avail_list, &swap_avail_head);
+			__del_from_avail_list(si);
 			spin_unlock(&si->lock);
 			goto nextsi;
 		}
-		if (cluster)
-			n_ret = swap_alloc_cluster(si, swp_entries);
-		else
+		if (cluster) {
+			if (!(si->flags & SWP_FILE))
+				n_ret = swap_alloc_cluster(si, swp_entries);
+		} else
 			n_ret = scan_swap_map_slots(si, SWAP_HAS_CACHE,
 						    n_goal, swp_entries);
 		spin_unlock(&si->lock);
@@ -962,7 +997,7 @@ nextsi:
 		 * swap_avail_head list then try it, otherwise start over
 		 * if we have not gotten any slots.
 		 */
-		if (plist_node_empty(&next->avail_list))
+		if (plist_node_empty(&next->avail_lists[node]))
 			goto start_over;
 	}
 
@@ -1168,22 +1203,57 @@ static void swapcache_free_cluster(swp_entry_t entry)
 	struct swap_cluster_info *ci;
 	struct swap_info_struct *si;
 	unsigned char *map;
-	unsigned int i;
+	unsigned int i, free_entries = 0;
+	unsigned char val;
 
-	si = swap_info_get(entry);
+	si = _swap_info_get(entry);
 	if (!si)
 		return;
 
 	ci = lock_cluster(si, offset);
+	VM_BUG_ON(!cluster_is_huge(ci));
 	map = si->swap_map + offset;
 	for (i = 0; i < SWAPFILE_CLUSTER; i++) {
-		VM_BUG_ON(map[i] != SWAP_HAS_CACHE);
-		map[i] = 0;
+		val = map[i];
+		VM_BUG_ON(!(val & SWAP_HAS_CACHE));
+		if (val == SWAP_HAS_CACHE)
+			free_entries++;
+	}
+	if (!free_entries) {
+		for (i = 0; i < SWAPFILE_CLUSTER; i++)
+			map[i] &= ~SWAP_HAS_CACHE;
 	}
+	cluster_clear_huge(ci);
 	unlock_cluster(ci);
-	mem_cgroup_uncharge_swap(entry, SWAPFILE_CLUSTER);
-	swap_free_cluster(si, idx);
-	spin_unlock(&si->lock);
+	if (free_entries == SWAPFILE_CLUSTER) {
+		spin_lock(&si->lock);
+		ci = lock_cluster(si, offset);
+		memset(map, 0, SWAPFILE_CLUSTER);
+		unlock_cluster(ci);
+		mem_cgroup_uncharge_swap(entry, SWAPFILE_CLUSTER);
+		swap_free_cluster(si, idx);
+		spin_unlock(&si->lock);
+	} else if (free_entries) {
+		for (i = 0; i < SWAPFILE_CLUSTER; i++, entry.val++) {
+			if (!__swap_entry_free(si, entry, SWAP_HAS_CACHE))
+				free_swap_slot(entry);
+		}
+	}
+}
+
+int split_swap_cluster(swp_entry_t entry)
+{
+	struct swap_info_struct *si;
+	struct swap_cluster_info *ci;
+	unsigned long offset = swp_offset(entry);
+
+	si = _swap_info_get(entry);
+	if (!si)
+		return -EBUSY;
+	ci = lock_cluster(si, offset);
+	cluster_clear_huge(ci);
+	unlock_cluster(ci);
+	return 0;
 }
 #else
 static inline void swapcache_free_cluster(swp_entry_t entry)
@@ -1332,29 +1402,161 @@ out:
 	return count;
 }
 
+#ifdef CONFIG_THP_SWAP
+static bool swap_page_trans_huge_swapped(struct swap_info_struct *si,
+					 swp_entry_t entry)
+{
+	struct swap_cluster_info *ci;
+	unsigned char *map = si->swap_map;
+	unsigned long roffset = swp_offset(entry);
+	unsigned long offset = round_down(roffset, SWAPFILE_CLUSTER);
+	int i;
+	bool ret = false;
+
+	ci = lock_cluster_or_swap_info(si, offset);
+	if (!ci || !cluster_is_huge(ci)) {
+		if (map[roffset] != SWAP_HAS_CACHE)
+			ret = true;
+		goto unlock_out;
+	}
+	for (i = 0; i < SWAPFILE_CLUSTER; i++) {
+		if (map[offset + i] != SWAP_HAS_CACHE) {
+			ret = true;
+			break;
+		}
+	}
+unlock_out:
+	unlock_cluster_or_swap_info(si, ci);
+	return ret;
+}
+
+static bool page_swapped(struct page *page)
+{
+	swp_entry_t entry;
+	struct swap_info_struct *si;
+
+	if (likely(!PageTransCompound(page)))
+		return page_swapcount(page) != 0;
+
+	page = compound_head(page);
+	entry.val = page_private(page);
+	si = _swap_info_get(entry);
+	if (si)
+		return swap_page_trans_huge_swapped(si, entry);
+	return false;
+}
+
+static int page_trans_huge_map_swapcount(struct page *page, int *total_mapcount,
+					 int *total_swapcount)
+{
+	int i, map_swapcount, _total_mapcount, _total_swapcount;
+	unsigned long offset = 0;
+	struct swap_info_struct *si;
+	struct swap_cluster_info *ci = NULL;
+	unsigned char *map = NULL;
+	int mapcount, swapcount = 0;
+
+	/* hugetlbfs shouldn't call it */
+	VM_BUG_ON_PAGE(PageHuge(page), page);
+
+	if (likely(!PageTransCompound(page))) {
+		mapcount = atomic_read(&page->_mapcount) + 1;
+		if (total_mapcount)
+			*total_mapcount = mapcount;
+		if (PageSwapCache(page))
+			swapcount = page_swapcount(page);
+		if (total_swapcount)
+			*total_swapcount = swapcount;
+		return mapcount + swapcount;
+	}
+
+	page = compound_head(page);
+
+	_total_mapcount = _total_swapcount = map_swapcount = 0;
+	if (PageSwapCache(page)) {
+		swp_entry_t entry;
+
+		entry.val = page_private(page);
+		si = _swap_info_get(entry);
+		if (si) {
+			map = si->swap_map;
+			offset = swp_offset(entry);
+		}
+	}
+	if (map)
+		ci = lock_cluster(si, offset);
+	for (i = 0; i < HPAGE_PMD_NR; i++) {
+		mapcount = atomic_read(&page[i]._mapcount) + 1;
+		_total_mapcount += mapcount;
+		if (map) {
+			swapcount = swap_count(map[offset + i]);
+			_total_swapcount += swapcount;
+		}
+		map_swapcount = max(map_swapcount, mapcount + swapcount);
+	}
+	unlock_cluster(ci);
+	if (PageDoubleMap(page)) {
+		map_swapcount -= 1;
+		_total_mapcount -= HPAGE_PMD_NR;
+	}
+	mapcount = compound_mapcount(page);
+	map_swapcount += mapcount;
+	_total_mapcount += mapcount;
+	if (total_mapcount)
+		*total_mapcount = _total_mapcount;
+	if (total_swapcount)
+		*total_swapcount = _total_swapcount;
+
+	return map_swapcount;
+}
+#else
+#define swap_page_trans_huge_swapped(si, entry)	swap_swapcount(si, entry)
+#define page_swapped(page)			(page_swapcount(page) != 0)
+
+static int page_trans_huge_map_swapcount(struct page *page, int *total_mapcount,
+					 int *total_swapcount)
+{
+	int mapcount, swapcount = 0;
+
+	/* hugetlbfs shouldn't call it */
+	VM_BUG_ON_PAGE(PageHuge(page), page);
+
+	mapcount = page_trans_huge_mapcount(page, total_mapcount);
+	if (PageSwapCache(page))
+		swapcount = page_swapcount(page);
+	if (total_swapcount)
+		*total_swapcount = swapcount;
+	return mapcount + swapcount;
+}
+#endif
+
 /*
  * We can write to an anon page without COW if there are no other references
  * to it.  And as a side-effect, free up its swap: because the old content
  * on disk will never be read, and seeking back there to write new content
  * later would only waste time away from clustering.
  *
- * NOTE: total_mapcount should not be relied upon by the caller if
+ * NOTE: total_map_swapcount should not be relied upon by the caller if
  * reuse_swap_page() returns false, but it may be always overwritten
  * (see the other implementation for CONFIG_SWAP=n).
  */
-bool reuse_swap_page(struct page *page, int *total_mapcount)
+bool reuse_swap_page(struct page *page, int *total_map_swapcount)
 {
-	int count;
+	int count, total_mapcount, total_swapcount;
 
 	VM_BUG_ON_PAGE(!PageLocked(page), page);
 	if (unlikely(PageKsm(page)))
 		return false;
-	count = page_trans_huge_mapcount(page, total_mapcount);
-	if (count <= 1 && PageSwapCache(page)) {
-		count += page_swapcount(page);
-		if (count != 1)
-			goto out;
+	count = page_trans_huge_map_swapcount(page, &total_mapcount,
+					      &total_swapcount);
+	if (total_map_swapcount)
+		*total_map_swapcount = total_mapcount + total_swapcount;
+	if (count == 1 && PageSwapCache(page) &&
+	    (likely(!PageTransCompound(page)) ||
+	     /* The remaining swap count will be freed soon */
+	     total_swapcount == page_swapcount(page))) {
 		if (!PageWriteback(page)) {
+			page = compound_head(page);
 			delete_from_swap_cache(page);
 			SetPageDirty(page);
 		} else {
@@ -1370,7 +1572,7 @@ bool reuse_swap_page(struct page *page, int *total_mapcount)
 			spin_unlock(&p->lock);
 		}
 	}
-out:
+
 	return count <= 1;
 }
 
@@ -1386,7 +1588,7 @@ int try_to_free_swap(struct page *page)
 		return 0;
 	if (PageWriteback(page))
 		return 0;
-	if (page_swapcount(page))
+	if (page_swapped(page))
 		return 0;
 
 	/*
@@ -1407,6 +1609,7 @@ int try_to_free_swap(struct page *page)
 	if (pm_suspended_storage())
 		return 0;
 
+	page = compound_head(page);
 	delete_from_swap_cache(page);
 	SetPageDirty(page);
 	return 1;
@@ -1428,7 +1631,8 @@ int free_swap_and_cache(swp_entry_t entry)
 	p = _swap_info_get(entry);
 	if (p) {
 		count = __swap_entry_free(p, entry, 1);
-		if (count == SWAP_HAS_CACHE) {
+		if (count == SWAP_HAS_CACHE &&
+		    !swap_page_trans_huge_swapped(p, entry)) {
 			page = find_get_page(swap_address_space(entry),
 					     swp_offset(entry));
 			if (page && !trylock_page(page)) {
@@ -1445,7 +1649,8 @@ int free_swap_and_cache(swp_entry_t entry)
 		 */
 		if (PageSwapCache(page) && !PageWriteback(page) &&
 		    (!page_mapped(page) || mem_cgroup_swap_full(page)) &&
-		    !swap_swapcount(p, entry)) {
+		    !swap_page_trans_huge_swapped(p, entry)) {
+			page = compound_head(page);
 			delete_from_swap_cache(page);
 			SetPageDirty(page);
 		}
@@ -1999,7 +2204,7 @@ int try_to_unuse(unsigned int type, bool frontswap,
 				.sync_mode = WB_SYNC_NONE,
 			};
 
-			swap_writepage(page, &wbc);
+			swap_writepage(compound_head(page), &wbc);
 			lock_page(page);
 			wait_on_page_writeback(page);
 		}
@@ -2012,8 +2217,9 @@ int try_to_unuse(unsigned int type, bool frontswap,
 		 * delete, since it may not have been written out to swap yet.
 		 */
 		if (PageSwapCache(page) &&
-		    likely(page_private(page) == entry.val))
-			delete_from_swap_cache(page);
+		    likely(page_private(page) == entry.val) &&
+		    !page_swapped(page))
+			delete_from_swap_cache(compound_head(page));
 
 		/*
 		 * So we could skip searching mms once swap count went
@@ -2226,10 +2432,24 @@ static int setup_swap_extents(struct swap_info_struct *sis, sector_t *span)
 	return generic_swapfile_activate(sis, swap_file, span);
 }
 
+static int swap_node(struct swap_info_struct *p)
+{
+	struct block_device *bdev;
+
+	if (p->bdev)
+		bdev = p->bdev;
+	else
+		bdev = p->swap_file->f_inode->i_sb->s_bdev;
+
+	return bdev ? bdev->bd_disk->node_id : NUMA_NO_NODE;
+}
+
 static void _enable_swap_info(struct swap_info_struct *p, int prio,
 				unsigned char *swap_map,
 				struct swap_cluster_info *cluster_info)
 {
+	int i;
+
 	if (prio >= 0)
 		p->prio = prio;
 	else
@@ -2239,7 +2459,16 @@ static void _enable_swap_info(struct swap_info_struct *p, int prio,
 	 * low-to-high, while swap ordering is high-to-low
 	 */
 	p->list.prio = -p->prio;
-	p->avail_list.prio = -p->prio;
+	for_each_node(i) {
+		if (p->prio >= 0)
+			p->avail_lists[i].prio = -p->prio;
+		else {
+			if (swap_node(p) == i)
+				p->avail_lists[i].prio = 1;
+			else
+				p->avail_lists[i].prio = -p->prio;
+		}
+	}
 	p->swap_map = swap_map;
 	p->cluster_info = cluster_info;
 	p->flags |= SWP_WRITEOK;
@@ -2258,9 +2487,7 @@ static void _enable_swap_info(struct swap_info_struct *p, int prio,
 	 * swap_info_struct.
 	 */
 	plist_add(&p->list, &swap_active_head);
-	spin_lock(&swap_avail_lock);
-	plist_add(&p->avail_list, &swap_avail_head);
-	spin_unlock(&swap_avail_lock);
+	add_to_avail_list(p);
 }
 
 static void enable_swap_info(struct swap_info_struct *p, int prio,
@@ -2345,17 +2572,19 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 		spin_unlock(&swap_lock);
 		goto out_dput;
 	}
-	spin_lock(&swap_avail_lock);
-	plist_del(&p->avail_list, &swap_avail_head);
-	spin_unlock(&swap_avail_lock);
+	del_from_avail_list(p);
 	spin_lock(&p->lock);
 	if (p->prio < 0) {
 		struct swap_info_struct *si = p;
+		int nid;
 
 		plist_for_each_entry_continue(si, &swap_active_head, list) {
 			si->prio++;
 			si->list.prio--;
-			si->avail_list.prio--;
+			for_each_node(nid) {
+				if (si->avail_lists[nid].prio != 1)
+					si->avail_lists[nid].prio--;
+			}
 		}
 		least_priority++;
 	}
@@ -2387,6 +2616,9 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 	if (p->flags & SWP_CONTINUED)
 		free_swap_count_continuations(p);
 
+	if (!p->bdev || !blk_queue_nonrot(bdev_get_queue(p->bdev)))
+		atomic_dec(&nr_rotate_swap);
+
 	mutex_lock(&swapon_mutex);
 	spin_lock(&swap_lock);
 	spin_lock(&p->lock);
@@ -2596,6 +2828,7 @@ static struct swap_info_struct *alloc_swap_info(void)
 {
 	struct swap_info_struct *p;
 	unsigned int type;
+	int i;
 
 	p = kzalloc(sizeof(*p), GFP_KERNEL);
 	if (!p)
@@ -2631,7 +2864,8 @@ static struct swap_info_struct *alloc_swap_info(void)
 	}
 	INIT_LIST_HEAD(&p->first_swap_extent.list);
 	plist_node_init(&p->list, 0);
-	plist_node_init(&p->avail_list, 0);
+	for_each_node(i)
+		plist_node_init(&p->avail_lists[i], 0);
 	p->flags = SWP_USED;
 	spin_unlock(&swap_lock);
 	spin_lock_init(&p->lock);
@@ -2873,6 +3107,9 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
+	if (!swap_avail_heads)
+		return -ENOMEM;
+
 	p = alloc_swap_info();
 	if (IS_ERR(p))
 		return PTR_ERR(p);
@@ -2963,7 +3200,8 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 			cluster = per_cpu_ptr(p->percpu_cluster, cpu);
 			cluster_set_null(&cluster->index);
 		}
-	}
+	} else
+		atomic_inc(&nr_rotate_swap);
 
 	error = swap_cgroup_swapon(p->type, maxpages);
 	if (error)
@@ -3052,7 +3290,8 @@ bad_swap:
 	p->flags = 0;
 	spin_unlock(&swap_lock);
 	vfree(swap_map);
-	vfree(cluster_info);
+	kvfree(cluster_info);
+	kvfree(frontswap_map);
 	if (swap_file) {
 		if (inode && S_ISREG(inode->i_mode)) {
 			inode_unlock(inode);
@@ -3457,3 +3696,21 @@ static void free_swap_count_continuations(struct swap_info_struct *si)
 		}
 	}
 }
+
+static int __init swapfile_init(void)
+{
+	int nid;
+
+	swap_avail_heads = kmalloc_array(nr_node_ids, sizeof(struct plist_head),
+					 GFP_KERNEL);
+	if (!swap_avail_heads) {
+		pr_emerg("Not enough memory for swap heads, swap is disabled\n");
+		return -ENOMEM;
+	}
+
+	for_each_node(nid)
+		plist_head_init(&swap_avail_heads[nid]);
+
+	return 0;
+}
+subsys_initcall(swapfile_init);