---

yaml
---
r: 127592
b: refs/heads/master
c: a7885eb
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 2733c06ac864ed40b9dfbbd5270f3f16949bd4a1
+refs/heads/master: a7885eb8ad465ec9db99ac5b5e6680f0ca8e11c8

trunk/Documentation/controllers/memory.txt

@@ -314,6 +314,15 @@ will be charged as a new owner of it.
 	showing for better debug please see the code for meanings.
 
 
+5.3 swappiness
+  Similar to /proc/sys/vm/swappiness, but affecting a hierarchy of groups only.
+
+  Following cgroup's swapiness can't be changed.
+  - root cgroup (uses /proc/sys/vm/swappiness).
+  - a cgroup which uses hierarchy and it has child cgroup.
+  - a cgroup which uses hierarchy and not the root of hierarchy.
+
+
 6. Hierarchy support
 
 The memory controller supports a deep hierarchy and hierarchical accounting.

trunk/include/linux/swap.h

@@ -214,7 +214,8 @@ static inline void lru_cache_add_active_file(struct page *page)
 extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
 					gfp_t gfp_mask);
 extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem,
-						gfp_t gfp_mask, bool noswap);
+						  gfp_t gfp_mask, bool noswap,
+						  unsigned int swappiness);
 extern int __isolate_lru_page(struct page *page, int mode, int file);
 extern unsigned long shrink_all_memory(unsigned long nr_pages);
 extern int vm_swappiness;

trunk/mm/memcontrol.c

@@ -164,6 +164,9 @@ struct mem_cgroup {
 	int		obsolete;
 	atomic_t	refcnt;
 
+	unsigned int	swappiness;
+
+
 	unsigned int inactive_ratio;
 
 	/*
@@ -636,6 +639,22 @@ static bool mem_cgroup_check_under_limit(struct mem_cgroup *mem)
 	return false;
 }
 
+static unsigned int get_swappiness(struct mem_cgroup *memcg)
+{
+	struct cgroup *cgrp = memcg->css.cgroup;
+	unsigned int swappiness;
+
+	/* root ? */
+	if (cgrp->parent == NULL)
+		return vm_swappiness;
+
+	spin_lock(&memcg->reclaim_param_lock);
+	swappiness = memcg->swappiness;
+	spin_unlock(&memcg->reclaim_param_lock);
+
+	return swappiness;
+}
+
 /*
  * Dance down the hierarchy if needed to reclaim memory. We remember the
  * last child we reclaimed from, so that we don't end up penalizing
@@ -656,7 +675,8 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
 	 * but there might be left over accounting, even after children
 	 * have left.
 	 */
-	ret = try_to_free_mem_cgroup_pages(root_mem, gfp_mask, noswap);
+	ret = try_to_free_mem_cgroup_pages(root_mem, gfp_mask, noswap,
+					   get_swappiness(root_mem));
 	if (mem_cgroup_check_under_limit(root_mem))
 		return 0;
 	if (!root_mem->use_hierarchy)
@@ -672,7 +692,8 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
 			cgroup_unlock();
 			continue;
 		}
-		ret = try_to_free_mem_cgroup_pages(next_mem, gfp_mask, noswap);
+		ret = try_to_free_mem_cgroup_pages(next_mem, gfp_mask, noswap,
+						   get_swappiness(next_mem));
 		if (mem_cgroup_check_under_limit(root_mem))
 			return 0;
 		cgroup_lock();
@@ -1400,7 +1421,8 @@ int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask)
 	rcu_read_unlock();
 
 	do {
-		progress = try_to_free_mem_cgroup_pages(mem, gfp_mask, true);
+		progress = try_to_free_mem_cgroup_pages(mem, gfp_mask, true,
+							get_swappiness(mem));
 		progress += mem_cgroup_check_under_limit(mem);
 	} while (!progress && --retry);
 
@@ -1468,7 +1490,9 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
 			break;
 
 		progress = try_to_free_mem_cgroup_pages(memcg,
-				GFP_KERNEL, false);
+							GFP_KERNEL,
+							false,
+							get_swappiness(memcg));
   		if (!progress)			retry_count--;
 	}
 
@@ -1512,7 +1536,8 @@ int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
 			break;
 
 		oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
-		try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL, true);
+		try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL, true,
+					     get_swappiness(memcg));
 		curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
 		if (curusage >= oldusage)
 			retry_count--;
@@ -1643,8 +1668,8 @@ static int mem_cgroup_force_empty(struct mem_cgroup *mem, bool free_all)
 			ret = -EINTR;
 			goto out;
 		}
-		progress = try_to_free_mem_cgroup_pages(mem,
-						  GFP_KERNEL, false);
+		progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL,
+						false, get_swappiness(mem));
 		if (!progress) {
 			nr_retries--;
 			/* maybe some writeback is necessary */
@@ -1864,6 +1889,37 @@ static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
 	return 0;
 }
 
+static u64 mem_cgroup_swappiness_read(struct cgroup *cgrp, struct cftype *cft)
+{
+	struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+
+	return get_swappiness(memcg);
+}
+
+static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
+				       u64 val)
+{
+	struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
+	struct mem_cgroup *parent;
+	if (val > 100)
+		return -EINVAL;
+
+	if (cgrp->parent == NULL)
+		return -EINVAL;
+
+	parent = mem_cgroup_from_cont(cgrp->parent);
+	/* If under hierarchy, only empty-root can set this value */
+	if ((parent->use_hierarchy) ||
+	    (memcg->use_hierarchy && !list_empty(&cgrp->children)))
+		return -EINVAL;
+
+	spin_lock(&memcg->reclaim_param_lock);
+	memcg->swappiness = val;
+	spin_unlock(&memcg->reclaim_param_lock);
+
+	return 0;
+}
+
 
 static struct cftype mem_cgroup_files[] = {
 	{
@@ -1902,6 +1958,11 @@ static struct cftype mem_cgroup_files[] = {
 		.write_u64 = mem_cgroup_hierarchy_write,
 		.read_u64 = mem_cgroup_hierarchy_read,
 	},
+	{
+		.name = "swappiness",
+		.read_u64 = mem_cgroup_swappiness_read,
+		.write_u64 = mem_cgroup_swappiness_write,
+	},
 };
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
@@ -2093,6 +2154,9 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
 	mem->last_scanned_child = NULL;
 	spin_lock_init(&mem->reclaim_param_lock);
 
+	if (parent)
+		mem->swappiness = get_swappiness(parent);
+
 	return &mem->css;
 free_out:
 	for_each_node_state(node, N_POSSIBLE)

trunk/mm/vmscan.c

@@ -1707,14 +1707,15 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
 
 unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
-						gfp_t gfp_mask,
-					   bool noswap)
+					   gfp_t gfp_mask,
+					   bool noswap,
+					   unsigned int swappiness)
 {
 	struct scan_control sc = {
 		.may_writepage = !laptop_mode,
 		.may_swap = 1,
 		.swap_cluster_max = SWAP_CLUSTER_MAX,
-		.swappiness = vm_swappiness,
+		.swappiness = swappiness,
 		.order = 0,
 		.mem_cgroup = mem_cont,
 		.isolate_pages = mem_cgroup_isolate_pages,