From 489c2a20a414351fe0813a727c34600c0f7292ae Mon Sep 17 00:00:00 2001
From: Johannes Weiner <hannes@cmpxchg.org>
Date: Wed, 20 Jan 2016 15:02:41 -0800
Subject: mm: memcontrol: introduce CONFIG_MEMCG_LEGACY_KMEM

Let the user know that CONFIG_MEMCG_KMEM does not apply to the cgroup2
interface. This also makes legacy-only code sections stand out better.

[arnd@arndb.de: mm: memcontrol: only manage socket pressure for CONFIG_INET]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 mm/memcontrol.c | 18 +++++++++---------
 mm/vmpressure.c |  2 ++
 2 files changed, 11 insertions(+), 9 deletions(-)

(limited to 'mm')

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 2239e6dd4d4c..92e8ab67b6df 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3001,7 +3001,7 @@ static void memcg_free_kmem(struct mem_cgroup *memcg)
 }
 #endif /* !CONFIG_SLOB */
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG_LEGACY_KMEM
 static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
 				   unsigned long limit)
 {
@@ -3025,7 +3025,7 @@ static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
 {
 	return -EINVAL;
 }
-#endif /* CONFIG_MEMCG_KMEM */
+#endif /* CONFIG_MEMCG_LEGACY_KMEM */
 
 
 /*
@@ -4039,7 +4039,7 @@ static struct cftype mem_cgroup_legacy_files[] = {
 		.seq_show = memcg_numa_stat_show,
 	},
 #endif
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG_LEGACY_KMEM
 	{
 		.name = "kmem.limit_in_bytes",
 		.private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT),
@@ -4266,13 +4266,13 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
 	if (ret)
 		return ret;
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_INET
+#ifdef CONFIG_MEMCG_LEGACY_KMEM
 	ret = tcp_init_cgroup(memcg);
 	if (ret)
 		return ret;
 #endif
 
-#ifdef CONFIG_INET
 	if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
 		static_branch_inc(&memcg_sockets_enabled_key);
 #endif
@@ -4329,7 +4329,7 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
 
 	memcg_free_kmem(memcg);
 
-#ifdef CONFIG_MEMCG_KMEM
+#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET)
 	tcp_destroy_cgroup(memcg);
 #endif
 
@@ -5558,7 +5558,7 @@ void sock_update_memcg(struct sock *sk)
 	memcg = mem_cgroup_from_task(current);
 	if (memcg == root_mem_cgroup)
 		goto out;
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG_LEGACY_KMEM
 	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !memcg->tcp_mem.active)
 		goto out;
 #endif
@@ -5587,7 +5587,7 @@ bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages)
 {
 	gfp_t gfp_mask = GFP_KERNEL;
 
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG_LEGACY_KMEM
 	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
 		struct page_counter *counter;
 
@@ -5619,7 +5619,7 @@ bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages)
  */
 void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages)
 {
-#ifdef CONFIG_MEMCG_KMEM
+#ifdef CONFIG_MEMCG_LEGACY_KMEM
 	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
 		page_counter_uncharge(&memcg->tcp_mem.memory_allocated,
 				      nr_pages);
diff --git a/mm/vmpressure.c b/mm/vmpressure.c
index 9a6c0704211c..89b1d441af4b 100644
--- a/mm/vmpressure.c
+++ b/mm/vmpressure.c
@@ -275,6 +275,7 @@ void vmpressure(gfp_t gfp, struct mem_cgroup *memcg, bool tree,
 
 		level = vmpressure_calc_level(scanned, reclaimed);
 
+#ifdef CONFIG_INET
 		if (level > VMPRESSURE_LOW) {
 			/*
 			 * Let the socket buffer allocator know that
@@ -286,6 +287,7 @@ void vmpressure(gfp_t gfp, struct mem_cgroup *memcg, bool tree,
 			 */
 			memcg->socket_pressure = jiffies + HZ;
 		}
+#endif
 	}
 }
 
-- 
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