[PATCH v2 02/13] memcg: Kernel memory accounting infrastructure.

[Suleiman Souhlal]

Enabled with CONFIG_CGROUP_MEM_RES_CTLR_KMEM.

Adds the following files:
    - memory.kmem.independent_kmem_limit
    - memory.kmem.usage_in_bytes
    - memory.kmem.limit_in_bytes

Signed-off-by: Suleiman Souhlal <suleiman@xxxxxxxxxx>
---
 mm/memcontrol.c |  136 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 135 insertions(+), 1 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 37ad2cb..e6fd558 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -220,6 +220,10 @@ enum memcg_flags {
 				 */
 	MEMCG_MEMSW_IS_MINIMUM,	/* Set when res.limit == memsw.limit */
 	MEMCG_OOM_KILL_DISABLE,	/* OOM-Killer disable */
+	MEMCG_INDEPENDENT_KMEM_LIMIT,	/*
+					 * kernel memory is not counted in
+					 * memory.usage_in_bytes
+					 */
 };
 
 /*
@@ -244,6 +248,10 @@ struct mem_cgroup {
 	 */
 	struct res_counter memsw;
 	/*
+	 * the counter to account for kernel memory usage.
+	 */
+	struct res_counter kmem;
+	/*
 	 * Per cgroup active and inactive list, similar to the
 	 * per zone LRU lists.
 	 */
@@ -355,6 +363,7 @@ enum charge_type {
 #define _MEM			(0)
 #define _MEMSWAP		(1)
 #define _OOM_TYPE		(2)
+#define _KMEM			(3)
 #define MEMFILE_PRIVATE(x, val)	(((x) << 16) | (val))
 #define MEMFILE_TYPE(val)	(((val) >> 16) & 0xffff)
 #define MEMFILE_ATTR(val)	((val) & 0xffff)
@@ -371,6 +380,8 @@ enum charge_type {
 
 static void mem_cgroup_get(struct mem_cgroup *memcg);
 static void mem_cgroup_put(struct mem_cgroup *memcg);
+static void memcg_kmem_init(struct mem_cgroup *memcg,
+    struct mem_cgroup *parent);
 
 static inline bool
 mem_cgroup_test_flag(const struct mem_cgroup *memcg, enum memcg_flags flag)
@@ -1435,6 +1446,10 @@ done:
 		res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
 		res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
 		res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
+	printk(KERN_INFO "kmem: usage %llukB, limit %llukB, failcnt %llu\n",
+		res_counter_read_u64(&memcg->kmem, RES_USAGE) >> 10,
+		res_counter_read_u64(&memcg->kmem, RES_LIMIT) >> 10,
+		res_counter_read_u64(&memcg->kmem, RES_FAILCNT));
 }
 
 /*
@@ -3868,6 +3883,9 @@ static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
 		else
 			val = res_counter_read_u64(&memcg->memsw, name);
 		break;
+	case _KMEM:
+		val = res_counter_read_u64(&memcg->kmem, name);
+		break;
 	default:
 		BUG();
 		break;
@@ -3900,8 +3918,15 @@ static int mem_cgroup_write(struct cgroup *cont, struct cftype *cft,
 			break;
 		if (type == _MEM)
 			ret = mem_cgroup_resize_limit(memcg, val);
-		else
+		else if (type == _MEMSWAP)
 			ret = mem_cgroup_resize_memsw_limit(memcg, val);
+		else if (type == _KMEM) {
+			if (!mem_cgroup_test_flag(memcg,
+			    MEMCG_INDEPENDENT_KMEM_LIMIT))
+				return -EINVAL;
+			ret = res_counter_set_limit(&memcg->kmem, val);
+		} else
+			return -EINVAL;
 		break;
 	case RES_SOFT_LIMIT:
 		ret = res_counter_memparse_write_strategy(buffer, &val);
@@ -4606,8 +4631,56 @@ static int mem_control_numa_stat_open(struct inode *unused, struct file *file)
 #endif /* CONFIG_NUMA */
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+static u64
+mem_cgroup_independent_kmem_limit_read(struct cgroup *cgrp, struct cftype *cft)
+{
+	return mem_cgroup_test_flag(mem_cgroup_from_cont(cgrp),
+	    MEMCG_INDEPENDENT_KMEM_LIMIT);
+}
+
+static int mem_cgroup_independent_kmem_limit_write(struct cgroup *cgrp,
+    struct cftype *cft, u64 val)
+{
+	struct mem_cgroup *memcg;
+
+	memcg = mem_cgroup_from_cont(cgrp);
+	if (val)
+		mem_cgroup_set_flag(memcg, MEMCG_INDEPENDENT_KMEM_LIMIT);
+	else {
+		mem_cgroup_clear_flag(memcg, MEMCG_INDEPENDENT_KMEM_LIMIT);
+		res_counter_set_limit(&memcg->kmem, RESOURCE_MAX);
+	}
+
+	return 0;
+}
+
+static struct cftype kmem_cgroup_files[] = {
+	{
+		.name = "kmem.independent_kmem_limit",
+		.write_u64 = mem_cgroup_independent_kmem_limit_write,
+		.read_u64 = mem_cgroup_independent_kmem_limit_read,
+	},
+	{
+		.name = "kmem.limit_in_bytes",
+		.private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT),
+		.write_string = mem_cgroup_write,
+		.read_u64 = mem_cgroup_read,
+	},
+	{
+		.name = "kmem.usage_in_bytes",
+		.private = MEMFILE_PRIVATE(_KMEM, RES_USAGE),
+		.read_u64 = mem_cgroup_read,
+	},
+};
+
 static int register_kmem_files(struct cgroup *cont, struct cgroup_subsys *ss)
 {
+	int ret;
+
+	ret = cgroup_add_files(cont, ss, kmem_cgroup_files,
+	    ARRAY_SIZE(kmem_cgroup_files));
+	if (ret)
+		return ret;
 	/*
 	 * Part of this would be better living in a separate allocation
 	 * function, leaving us with just the cgroup tree population work.
@@ -4621,6 +4694,10 @@ static int register_kmem_files(struct cgroup *cont, struct cgroup_subsys *ss)
 static void kmem_cgroup_destroy(struct cgroup_subsys *ss,
 				struct cgroup *cont)
 {
+	struct mem_cgroup *memcg;
+
+	memcg = mem_cgroup_from_cont(cont);
+	BUG_ON(res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0);
 	mem_cgroup_sockets_destroy(cont, ss);
 }
 #else
@@ -4980,6 +5057,8 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont)
 	}
 	memcg->last_scanned_node = MAX_NUMNODES;
 	INIT_LIST_HEAD(&memcg->oom_notify);
+	memcg_kmem_init(memcg, parent && mem_cgroup_test_flag(parent,
+	    MEMCG_USE_HIERARCHY) ? parent : NULL);
 
 	if (parent)
 		memcg->swappiness = mem_cgroup_swappiness(parent);
@@ -5561,3 +5640,58 @@ static int __init enable_swap_account(char *s)
 __setup("swapaccount=", enable_swap_account);
 
 #endif
+
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+int
+memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, long long delta)
+{
+	struct res_counter *fail_res;
+	struct mem_cgroup *_memcg;
+	int may_oom, ret;
+
+	may_oom = (gfp & __GFP_WAIT) && (gfp & __GFP_FS) &&
+	    !(gfp & __GFP_NORETRY);
+
+	ret = 0;
+
+	_memcg = memcg;
+	if (memcg && !mem_cgroup_test_flag(memcg,
+	    MEMCG_INDEPENDENT_KMEM_LIMIT)) {
+		ret = __mem_cgroup_try_charge(NULL, gfp, delta / PAGE_SIZE,
+		    &_memcg, may_oom);
+		if (ret == -ENOMEM)
+			return ret;
+	}
+
+	if (memcg && _memcg == memcg)
+		ret = res_counter_charge(&memcg->kmem, delta, &fail_res);
+
+	return ret;
+}
+
+void
+memcg_uncharge_kmem(struct mem_cgroup *memcg, long long delta)
+{
+	if (memcg)
+		res_counter_uncharge(&memcg->kmem, delta);
+
+	if (memcg && !mem_cgroup_test_flag(memcg, MEMCG_INDEPENDENT_KMEM_LIMIT))
+		res_counter_uncharge(&memcg->res, delta);
+}
+
+static void
+memcg_kmem_init(struct mem_cgroup *memcg, struct mem_cgroup *parent)
+{
+	struct res_counter *parent_res;
+
+	parent_res = NULL;
+	if (parent && parent != root_mem_cgroup)
+		parent_res = &parent->kmem;
+	res_counter_init(&memcg->kmem, parent_res);
+}
+#else /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
+static void
+memcg_kmem_init(struct mem_cgroup *memcg, struct mem_cgroup *parent)
+{
+}
+#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
-- 
1.7.7.3

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