mm: memcg: put cgroup v1-specific memcg data under CONFIG_MEMCG_V1

PATCH In review Roman Gushchin 4 participants 23 messages Jun 28, 2024 – Jul 5, 2024

Subsystems (3)

Memory management Scheduler memcg

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Roman Gushchin

author maintainer

2024-06-28 21:03 UTC #0 lore raw

cover mm: memcg: put cgroup v1-specific memcg data under CONFIG_MEMCG_V1

This patchset puts all cgroup v1's members of struct mem_cgroup, struct mem_cgroup_per_node and struct task_struct under the CONFIG_MEMCG_V1 config option. If cgroup v1 support is not required (and it's true for many cgroup users these days), it allows to save a bit of memory and compile out some code, some of which is on relatively hot paths. It also structures the code a bit better by grouping cgroup v1-specific stuff in one place.

Roman Gushchin (9):
mm: memcg: move memcg_account_kmem() to memcontrol-v1.c
mm: memcg: factor out legacy socket memory accounting code
mm: memcg: guard cgroup v1-specific code in
mem_cgroup_print_oom_meminfo()
mm: memcg: gather memcg1-specific fields initialization in

    memcg1_memcg_init()

mm: memcg: guard memcg1-specific fields accesses in mm/memcontrol.c
mm: memcg: put memcg1-specific struct mem_cgroup's members under
CONFIG_MEMCG_V1
mm: memcg: guard memcg1-specific members of struct mem_cgroup_per_node
mm: memcg: put struct task_struct::memcg_in_oom under CONFIG_MEMCG_V1
mm: memcg: put struct task_struct::in_user_fault under CONFIG_MEMCG_V1

 include/linux/memcontrol.h | 147 +++++++++++++++++++------------------
 include/linux/sched.h      |   6 +-
 mm/memcontrol-v1.c         |  38 ++++++++++
 mm/memcontrol-v1.h         |  20 +++++
 mm/memcontrol.c            |  70 +++++++-----------
 5 files changed, 164 insertions(+), 117 deletions(-)

Signature · 1 line

2.45.2.803.g4e1b14247a-goog

Roman Gushchin

author maintainer

2024-06-28 21:03 UTC #1 lore raw

PATCH 1/9 mm: memcg: move memcg_account_kmem() to memcontrol-v1.c

memcg_account_kmem() consists of a trivial statistics change via mod_memcg_state() call and a relatively large memcg1-specific part.

Let's factor out the mod_memcg_state() call and move the rest into the mm/memcontrol-v1.c file. Also rename memcg_account_kmem() into memcg1_account_kmem() for consistency.

Signed-off-by Roman Gushchin <[email protected]>

---
 mm/memcontrol-v1.c | 12 ++++++++++++
 mm/memcontrol-v1.h |  2 ++
 mm/memcontrol.c    | 31 ++++++++++---------------------
 3 files changed, 24 insertions(+), 21 deletions(-)

mm/memcontrol-v1.c +12 -0

index 6ac47954eefc..c73a0ff0cc39 100644
@@ -2913,6 +2913,18 @@ struct cftype memsw_files[] = {
 	{ },	/* terminate */
 };
 
+#ifdef CONFIG_MEMCG_KMEM
+void memcg1_account_kmem(struct mem_cgroup *memcg, int nr_pages)
+{
+	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
+		if (nr_pages > 0)
+			page_counter_charge(&memcg->kmem, nr_pages);
+		else
+			page_counter_uncharge(&memcg->kmem, -nr_pages);
+	}
+}
+#endif /* CONFIG_MEMCG_KMEM */
+
 static int __init memcg1_init(void)
 {
 	int node;

mm/memcontrol-v1.h +2 -0

index 64b053d7f131..61620e2b0bf0 100644
@@ -107,6 +107,7 @@ void memcg1_check_events(struct mem_cgroup *memcg, int nid);
 
 void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s);
 
+void memcg1_account_kmem(struct mem_cgroup *memcg, int nr_pages);
 extern struct cftype memsw_files[];
 extern struct cftype mem_cgroup_legacy_files[];

@@ -125,6 +126,7 @@ static inline void memcg1_check_events(struct mem_cgroup *memcg, int nid) {}
 
 static inline void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s) {}
 
+static inline void memcg1_account_kmem(struct mem_cgroup *memcg, int nr_pages) {}
 extern struct cftype memsw_files[];
 extern struct cftype mem_cgroup_legacy_files[];
 #endif	/* CONFIG_MEMCG_V1 */

mm/memcontrol.c +10 ~~-21~~

index c251bbe35f4b..802a077e2e2f 100644
@@ -1718,7 +1718,6 @@ static DEFINE_MUTEX(percpu_charge_mutex);
 static struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock);
 static bool obj_stock_flush_required(struct memcg_stock_pcp *stock,
 				     struct mem_cgroup *root_memcg);
-static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages);
 
 #else
 static inline struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock)

@@ -1730,9 +1729,6 @@ static bool obj_stock_flush_required(struct memcg_stock_pcp *stock,
 {
 	return false;
 }
-static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages)
-{
-}
 #endif
 
 /**

@@ -2642,18 +2638,6 @@ struct obj_cgroup *get_obj_cgroup_from_folio(struct folio *folio)
 	return objcg;
 }
 
-static void memcg_account_kmem(struct mem_cgroup *memcg, int nr_pages)
-{
-	mod_memcg_state(memcg, MEMCG_KMEM, nr_pages);
-	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
-		if (nr_pages > 0)
-			page_counter_charge(&memcg->kmem, nr_pages);
-		else
-			page_counter_uncharge(&memcg->kmem, -nr_pages);
-	}
-}
-
-
 /*
  * obj_cgroup_uncharge_pages: uncharge a number of kernel pages from a objcg
  * @objcg: object cgroup to uncharge

@@ -2666,7 +2650,8 @@ static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg,
 
 	memcg = get_mem_cgroup_from_objcg(objcg);
 
-	memcg_account_kmem(memcg, -nr_pages);
+	mod_memcg_state(memcg, MEMCG_KMEM, -nr_pages);
+	memcg1_account_kmem(memcg, -nr_pages);
 	refill_stock(memcg, nr_pages);
 
 	css_put(&memcg->css);

@@ -2692,7 +2677,8 @@ static int obj_cgroup_charge_pages(struct obj_cgroup *objcg, gfp_t gfp,
 	if (ret)
 		goto out;
 
-	memcg_account_kmem(memcg, nr_pages);
+	mod_memcg_state(memcg, MEMCG_KMEM, nr_pages);
+	memcg1_account_kmem(memcg, nr_pages);
 out:
 	css_put(&memcg->css);

@@ -2845,7 +2831,8 @@ static struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock)
 
 			memcg = get_mem_cgroup_from_objcg(old);
 
-			memcg_account_kmem(memcg, -nr_pages);
+			mod_memcg_state(memcg, MEMCG_KMEM, -nr_pages);
+			memcg1_account_kmem(memcg, -nr_pages);
 			__refill_stock(memcg, nr_pages);
 
 			css_put(&memcg->css);

@@ -4806,8 +4793,10 @@ static void uncharge_batch(const struct uncharge_gather *ug)
 		page_counter_uncharge(&ug->memcg->memory, ug->nr_memory);
 		if (do_memsw_account())
 			page_counter_uncharge(&ug->memcg->memsw, ug->nr_memory);
-		if (ug->nr_kmem)
-			memcg_account_kmem(ug->memcg, -ug->nr_kmem);
+		if (ug->nr_kmem) {
+			mod_memcg_state(ug->memcg, MEMCG_KMEM, -ug->nr_kmem);
+			memcg1_account_kmem(ug->memcg, -ug->nr_kmem);
+		}
 		memcg1_oom_recover(ug->memcg);
 	}

Signature · 1 line

2.45.2.803.g4e1b14247a-goog

Shakeel Butt

maintainer Acked-by on v1 1/9

2024-06-29 00:30 UTC #2 lore raw

Re: [PATCH v1 1/9] mm: memcg: move memcg_account_kmem() to memcontrol-v1.c

Quoted 8 lines · Roman Gushchin

memcg_account_kmem() consists of a trivial statistics change via mod_memcg_state() call and a relatively large memcg1-specific part.
Let's factor out the mod_memcg_state() call and move the rest into the mm/memcontrol-v1.c file. Also rename memcg_account_kmem() into memcg1_account_kmem() for consistency.
Signed-off-by Roman Gushchin <[email protected]>

Acked-by Shakeel Butt <[email protected]>

Roman Gushchin

author maintainer

2024-06-28 21:03 UTC #3 lore raw

PATCH 2/9 mm: memcg: factor out legacy socket memory accounting code

In reply to Roman Gushchin

Move out the legacy cgroup v1 socket memory accounting code into mm/memcontrol-v1.c.

This commit introduces three new functions: memcg1_tcpmem_active(), memcg1_charge_skmem() and memcg1_uncharge_skmem(), which contain all cgroup v1-specific code and become trivial if CONFIG_MEMCG_V1 isn't set.

Note, that !!memcg->tcpmem_pressure check in mem_cgroup_under_socket_pressure() can't be easily moved into memcontrol-v1.h without including memcontrol-v1.h from memcontrol.h which isn't a good idea, so it's better to just #ifdef it.

Signed-off-by Roman Gushchin <[email protected]>

---
 include/linux/memcontrol.h |  2 ++
 mm/memcontrol-v1.c         | 17 +++++++++++++++++
 mm/memcontrol-v1.h         | 16 ++++++++++++++++
 mm/memcontrol.c            | 22 +++++-----------------
 4 files changed, 40 insertions(+), 17 deletions(-)

include/linux/memcontrol.h +2 -0

index 796cfa842346..44ab6394c9ed 100644
@@ -1650,8 +1650,10 @@ void mem_cgroup_sk_alloc(struct sock *sk);
 void mem_cgroup_sk_free(struct sock *sk);
 static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
 {
+#ifdef CONFIG_MEMCG_V1
 	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
 		return !!memcg->tcpmem_pressure;
+#endif /* CONFIG_MEMCG_V1 */
 	do {
 		if (time_before(jiffies, READ_ONCE(memcg->socket_pressure)))
 			return true;

mm/memcontrol-v1.c +17 -0

index c73a0ff0cc39..c9b4c3e4797d 100644
@@ -2925,6 +2925,23 @@ void memcg1_account_kmem(struct mem_cgroup *memcg, int nr_pages)
 }
 #endif /* CONFIG_MEMCG_KMEM */
 
+bool memcg1_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
+			 gfp_t gfp_mask)
+{
+	struct page_counter *fail;
+
+	if (page_counter_try_charge(&memcg->tcpmem, nr_pages, &fail)) {
+		memcg->tcpmem_pressure = 0;
+		return true;
+	}
+	memcg->tcpmem_pressure = 1;
+	if (gfp_mask & __GFP_NOFAIL) {
+		page_counter_charge(&memcg->tcpmem, nr_pages);
+		return true;
+	}
+	return false;
+}
+
 static int __init memcg1_init(void)
 {
 	int node;

mm/memcontrol-v1.h +16 -0

index 61620e2b0bf0..c8e5119223bb 100644
@@ -108,6 +108,17 @@ void memcg1_check_events(struct mem_cgroup *memcg, int nid);
 void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s);
 
 void memcg1_account_kmem(struct mem_cgroup *memcg, int nr_pages);
+static inline bool memcg1_tcpmem_active(struct mem_cgroup *memcg)
+{
+	return memcg->tcpmem_active;
+}
+bool memcg1_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
+			 gfp_t gfp_mask);
+static inline void memcg1_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages)
+{
+	page_counter_uncharge(&memcg->tcpmem, nr_pages);
+}
+
 extern struct cftype memsw_files[];
 extern struct cftype mem_cgroup_legacy_files[];

@@ -127,6 +138,11 @@ static inline void memcg1_check_events(struct mem_cgroup *memcg, int nid) {}
 static inline void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s) {}
 
 static inline void memcg1_account_kmem(struct mem_cgroup *memcg, int nr_pages) {}
+static inline bool memcg1_tcpmem_active(struct mem_cgroup *memcg) { return false; }
+static inline bool memcg1_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
+				       gfp_t gfp_mask) { return true; }
+static inline void memcg1_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages) {}
+
 extern struct cftype memsw_files[];
 extern struct cftype mem_cgroup_legacy_files[];
 #endif	/* CONFIG_MEMCG_V1 */

mm/memcontrol.c +5 ~~-17~~

index 802a077e2e2f..2c0605bbbb31 100644
@@ -3788,7 +3788,7 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
 	if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
 		static_branch_dec(&memcg_sockets_enabled_key);
 
-	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg->tcpmem_active)
+	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg1_tcpmem_active(memcg))
 		static_branch_dec(&memcg_sockets_enabled_key);
 
 #if defined(CONFIG_MEMCG_KMEM)

@@ -5013,7 +5013,7 @@ void mem_cgroup_sk_alloc(struct sock *sk)
 	memcg = mem_cgroup_from_task(current);
 	if (mem_cgroup_is_root(memcg))
 		goto out;
-	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !memcg->tcpmem_active)
+	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !memcg1_tcpmem_active(memcg))
 		goto out;
 	if (css_tryget(&memcg->css))
 		sk->sk_memcg = memcg;

@@ -5039,20 +5039,8 @@ void mem_cgroup_sk_free(struct sock *sk)
 bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
 			     gfp_t gfp_mask)
 {
-	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
-		struct page_counter *fail;
-
-		if (page_counter_try_charge(&memcg->tcpmem, nr_pages, &fail)) {
-			memcg->tcpmem_pressure = 0;
-			return true;
-		}
-		memcg->tcpmem_pressure = 1;
-		if (gfp_mask & __GFP_NOFAIL) {
-			page_counter_charge(&memcg->tcpmem, nr_pages);
-			return true;
-		}
-		return false;
-	}
+	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
+		return memcg1_charge_skmem(memcg, nr_pages, gfp_mask);
 
 	if (try_charge(memcg, gfp_mask, nr_pages) == 0) {
 		mod_memcg_state(memcg, MEMCG_SOCK, nr_pages);

@@ -5070,7 +5058,7 @@ 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)
 {
 	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
-		page_counter_uncharge(&memcg->tcpmem, nr_pages);
+		memcg1_uncharge_skmem(memcg, nr_pages);
 		return;
 	}

Signature · 1 line

2.45.2.803.g4e1b14247a-goog

Shakeel Butt

maintainer Acked-by on v1 2/9

2024-06-29 00:39 UTC #4 lore raw

Re: [PATCH v1 2/9] mm: memcg: factor out legacy socket memory accounting code

Quoted 8 lines · Roman Gushchin

Move out the legacy cgroup v1 socket memory accounting code into mm/memcontrol-v1.c.
This commit introduces three new functions: memcg1_tcpmem_active(), memcg1_charge_skmem() and memcg1_uncharge_skmem(), which contain all cgroup v1-specific code and become trivial if CONFIG_MEMCG_V1 isn't set.

Quoted 6 lines

Note, that !!memcg->tcpmem_pressure check in mem_cgroup_under_socket_pressure() can't be easily moved into memcontrol-v1.h without including memcontrol-v1.h from memcontrol.h which isn't a good idea, so it's better to just #ifdef it.
Signed-off-by Roman Gushchin <[email protected]>

Acked-by Shakeel Butt <[email protected]>

[...]

mm/memcontrol-v1.h static inline void memcg1_check_events(struct mem_cgroup *memcg, int nid) {} · line 143

Quoted 2 lines

mm/memcontrol-v1.h +2 -0

+static inline bool memcg1_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
+				       gfp_t gfp_mask) { return true; }

I wonder if it really matters if we return true or false from above. If CONFIG_MEMCG_V1=n then cgroup_subsys_on_dfl() is always true, so memcg1_charge_skmem() should never be called. Anyways just wanted to point this out, nothing actionable.

[...]

Quoted 2 lines

mm/memcontrol.c +2 -0

+	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
+		return memcg1_charge_skmem(memcg, nr_pages, gfp_mask);

Roman Gushchin

author maintainer

2024-06-28 21:03 UTC #5 lore raw

PATCH 3/9 mm: memcg: guard cgroup v1-specific code in mem_cgroup_print_oom_meminfo()

In reply to Roman Gushchin

Put cgroup v1-specific code in mem_cgroup_print_oom_meminfo() under CONFIG_MEMCG_V1.

Signed-off-by Roman Gushchin <[email protected]>

---
 mm/memcontrol.c | 2 ++
 1 file changed, 2 insertions(+)

mm/memcontrol.c +2 -0

index 2c0605bbbb31..b69abd327549 100644
@@ -1532,6 +1532,7 @@ void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg)
 		pr_info("swap: usage %llukB, limit %llukB, failcnt %lu\n",
 			K((u64)page_counter_read(&memcg->swap)),
 			K((u64)READ_ONCE(memcg->swap.max)), memcg->swap.failcnt);
+#ifdef CONFIG_MEMCG_V1
 	else {
 		pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
 			K((u64)page_counter_read(&memcg->memsw)),

@@ -1540,6 +1541,7 @@ void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg)
 			K((u64)page_counter_read(&memcg->kmem)),
 			K((u64)memcg->kmem.max), memcg->kmem.failcnt);
 	}
+#endif
 
 	pr_info("Memory cgroup stats for ");
 	pr_cont_cgroup_path(memcg->css.cgroup);

Signature · 1 line

2.45.2.803.g4e1b14247a-goog

Shakeel Butt

maintainer Acked-by on v1 3/9

2024-06-29 00:40 UTC #6 lore raw

Re: [PATCH v1 3/9] mm: memcg: guard cgroup v1-specific code in mem_cgroup_print_oom_meminfo()

Quoted 4 lines · Roman Gushchin

Put cgroup v1-specific code in mem_cgroup_print_oom_meminfo() under CONFIG_MEMCG_V1.
Signed-off-by Roman Gushchin <[email protected]>

Acked-by Shakeel Butt <[email protected]>

Roman Gushchin

author maintainer

2024-06-28 21:03 UTC #7 lore raw

PATCH 4/9 mm: memcg: gather memcg1-specific fields initialization in memcg1_memcg_init()

In reply to Roman Gushchin

Gather all memcg1-specific struct mem_cgroup's members initialization in a new memcg1_memcg_init() function, defined in mm/memcontrol-v1.c. Obviously, if CONFIG_MEMCG_V1 is not set, there is no need to initialize these fields, so the function becomes trivial.

Signed-off-by Roman Gushchin <[email protected]>

---
 mm/memcontrol-v1.c | 9 +++++++++
 mm/memcontrol-v1.h | 2 ++
 mm/memcontrol.c    | 6 +-----
 3 files changed, 12 insertions(+), 5 deletions(-)

mm/memcontrol-v1.c +9 -0

index c9b4c3e4797d..5fa48a45e34b 100644
@@ -1961,6 +1961,15 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
 	return ret;
 }
 
+void memcg1_memcg_init(struct mem_cgroup *memcg)
+{
+	INIT_LIST_HEAD(&memcg->oom_notify);
+	mutex_init(&memcg->thresholds_lock);
+	spin_lock_init(&memcg->move_lock);
+	INIT_LIST_HEAD(&memcg->event_list);
+	spin_lock_init(&memcg->event_list_lock);
+}
+
 void memcg1_css_offline(struct mem_cgroup *memcg)
 {
 	struct mem_cgroup_event *event, *tmp;

mm/memcontrol-v1.h +2 -0

index c8e5119223bb..6545fa1b7d09 100644
@@ -76,6 +76,7 @@ int memory_stat_show(struct seq_file *m, void *v);
 
 /* Cgroup v1-specific declarations */
 #ifdef CONFIG_MEMCG_V1
+void memcg1_memcg_init(struct mem_cgroup *memcg);
 void memcg1_remove_from_trees(struct mem_cgroup *memcg);
 
 static inline void memcg1_soft_limit_reset(struct mem_cgroup *memcg)

@@ -124,6 +125,7 @@ extern struct cftype mem_cgroup_legacy_files[];
 
 #else	/* CONFIG_MEMCG_V1 */
 
+static inline void memcg1_memcg_init(struct mem_cgroup *memcg) {}
 static inline void memcg1_remove_from_trees(struct mem_cgroup *memcg) {}
 static inline void memcg1_soft_limit_reset(struct mem_cgroup *memcg) {}
 static inline bool memcg1_wait_acct_move(struct mem_cgroup *memcg) { return false; }

mm/memcontrol.c +1 -5

index b69abd327549..e78ed54d46d2 100644
@@ -3624,13 +3624,9 @@ static struct mem_cgroup *mem_cgroup_alloc(struct mem_cgroup *parent)
 		goto fail;
 
 	INIT_WORK(&memcg->high_work, high_work_func);
-	INIT_LIST_HEAD(&memcg->oom_notify);
-	mutex_init(&memcg->thresholds_lock);
-	spin_lock_init(&memcg->move_lock);
 	vmpressure_init(&memcg->vmpressure);
-	INIT_LIST_HEAD(&memcg->event_list);
-	spin_lock_init(&memcg->event_list_lock);
 	memcg->socket_pressure = jiffies;
+	memcg1_memcg_init(memcg);
 #ifdef CONFIG_MEMCG_KMEM
 	memcg->kmemcg_id = -1;
 	INIT_LIST_HEAD(&memcg->objcg_list);

Signature · 1 line

2.45.2.803.g4e1b14247a-goog

Shakeel Butt

maintainer Acked-by on v1 4/9

2024-06-29 00:43 UTC #8 lore raw

Re: [PATCH v1 4/9] mm: memcg: gather memcg1-specific fields initialization in memcg1_memcg_init()

Quoted 6 lines · Roman Gushchin

Gather all memcg1-specific struct mem_cgroup's members initialization in a new memcg1_memcg_init() function, defined in mm/memcontrol-v1.c. Obviously, if CONFIG_MEMCG_V1 is not set, there is no need to initialize these fields, so the function becomes trivial.
Signed-off-by Roman Gushchin <[email protected]>

Acked-by Shakeel Butt <[email protected]>

Roman Gushchin

author maintainer

2024-06-28 21:03 UTC #9 lore raw

PATCH 5/9 mm: memcg: guard memcg1-specific fields accesses in mm/memcontrol.c

In reply to Roman Gushchin

There are only few memcg1-specific struct mem_cgroup's members accesses left in mm/memcontrol.c. Let's guard them with the CONFIG_MEMCG_V1 config option.

Signed-off-by Roman Gushchin <[email protected]>

---
 mm/memcontrol.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

mm/memcontrol.c +7 -2

index e78ed54d46d2..661e3a70e685 100644
@@ -3672,20 +3672,23 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
 	page_counter_set_high(&memcg->swap, PAGE_COUNTER_MAX);
 	if (parent) {
 		WRITE_ONCE(memcg->swappiness, mem_cgroup_swappiness(parent));
-		WRITE_ONCE(memcg->oom_kill_disable, READ_ONCE(parent->oom_kill_disable));
 
 		page_counter_init(&memcg->memory, &parent->memory);
 		page_counter_init(&memcg->swap, &parent->swap);
+#ifdef CONFIG_MEMCG_V1
+		WRITE_ONCE(memcg->oom_kill_disable, READ_ONCE(parent->oom_kill_disable));
 		page_counter_init(&memcg->kmem, &parent->kmem);
 		page_counter_init(&memcg->tcpmem, &parent->tcpmem);
+#endif
 	} else {
 		init_memcg_stats();
 		init_memcg_events();
 		page_counter_init(&memcg->memory, NULL);
 		page_counter_init(&memcg->swap, NULL);
+#ifdef CONFIG_MEMCG_V1
 		page_counter_init(&memcg->kmem, NULL);
 		page_counter_init(&memcg->tcpmem, NULL);
-
+#endif
 		root_mem_cgroup = memcg;
 		return &memcg->css;
 	}

@@ -3820,8 +3823,10 @@ static void mem_cgroup_css_reset(struct cgroup_subsys_state *css)
 
 	page_counter_set_max(&memcg->memory, PAGE_COUNTER_MAX);
 	page_counter_set_max(&memcg->swap, PAGE_COUNTER_MAX);
+#ifdef CONFIG_MEMCG_V1
 	page_counter_set_max(&memcg->kmem, PAGE_COUNTER_MAX);
 	page_counter_set_max(&memcg->tcpmem, PAGE_COUNTER_MAX);
+#endif
 	page_counter_set_min(&memcg->memory, 0);
 	page_counter_set_low(&memcg->memory, 0);
 	page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX);

Signature · 1 line

2.45.2.803.g4e1b14247a-goog

Shakeel Butt

maintainer Acked-by on v1 5/9

2024-06-29 00:49 UTC #10 lore raw

Re: [PATCH v1 5/9] mm: memcg: guard memcg1-specific fields accesses in mm/memcontrol.c

Quoted 5 lines · Roman Gushchin

There are only few memcg1-specific struct mem_cgroup's members accesses left in mm/memcontrol.c. Let's guard them with the CONFIG_MEMCG_V1 config option.
Signed-off-by Roman Gushchin <[email protected]>

Acked-by Shakeel Butt <[email protected]>

Roman Gushchin

author maintainer

2024-06-28 21:04 UTC #11 lore raw

PATCH 6/9 mm: memcg: put memcg1-specific struct mem_cgroup's members under CONFIG_MEMCG_V1

In reply to Roman Gushchin

Put memcg1-specific members of struct mem_cgroup under the CONFIG_MEMCG_V1 config option. Also group them close to the end of struct mem_cgroup just before the dynamic per-node part.

Signed-off-by Roman Gushchin <[email protected]>

---
 include/linux/memcontrol.h | 103 +++++++++++++++++++------------------
 1 file changed, 53 insertions(+), 50 deletions(-)

include/linux/memcontrol.h +53 ~~-50~~

index 44ab6394c9ed..107b0c5d6eab 100644
@@ -188,10 +188,6 @@ struct mem_cgroup {
 		struct page_counter memsw;	/* v1 only */
 	};
 
-	/* Legacy consumer-oriented counters */
-	struct page_counter kmem;		/* v1 only */
-	struct page_counter tcpmem;		/* v1 only */
-
 	/* Range enforcement for interrupt charges */
 	struct work_struct high_work;

@@ -205,8 +201,6 @@ struct mem_cgroup {
 	bool zswap_writeback;
 #endif
 
-	unsigned long soft_limit;
-
 	/* vmpressure notifications */
 	struct vmpressure vmpressure;

@@ -215,13 +209,7 @@ struct mem_cgroup {
 	 */
 	bool oom_group;
 
-	/* protected by memcg_oom_lock */
-	bool		oom_lock;
-	int		under_oom;
-
-	int	swappiness;
-	/* OOM-Killer disable */
-	int		oom_kill_disable;
+	int swappiness;
 
 	/* memory.events and memory.events.local */
 	struct cgroup_file events_file;

@@ -230,27 +218,6 @@ struct mem_cgroup {
 	/* handle for "memory.swap.events" */
 	struct cgroup_file swap_events_file;
 
-	/* protect arrays of thresholds */
-	struct mutex thresholds_lock;
-
-	/* thresholds for memory usage. RCU-protected */
-	struct mem_cgroup_thresholds thresholds;
-
-	/* thresholds for mem+swap usage. RCU-protected */
-	struct mem_cgroup_thresholds memsw_thresholds;
-
-	/* For oom notifier event fd */
-	struct list_head oom_notify;
-
-	/*
-	 * Should we move charges of a task when a task is moved into this
-	 * mem_cgroup ? And what type of charges should we move ?
-	 */
-	unsigned long move_charge_at_immigrate;
-	/* taken only while moving_account > 0 */
-	spinlock_t		move_lock;
-	unsigned long		move_lock_flags;
-
 	CACHELINE_PADDING(_pad1_);
 
 	/* memory.stat */

@@ -267,10 +234,6 @@ struct mem_cgroup {
 	 */
 	unsigned long		socket_pressure;
 
-	/* Legacy tcp memory accounting */
-	bool			tcpmem_active;
-	int			tcpmem_pressure;
-
 #ifdef CONFIG_MEMCG_KMEM
 	int kmemcg_id;
 	/*

@@ -284,14 +247,6 @@ struct mem_cgroup {
 	struct list_head objcg_list;
 #endif
 
-	CACHELINE_PADDING(_pad2_);
-
-	/*
-	 * set > 0 if pages under this cgroup are moving to other cgroup.
-	 */
-	atomic_t		moving_account;
-	struct task_struct	*move_lock_task;
-
 	struct memcg_vmstats_percpu __percpu *vmstats_percpu;
 
 #ifdef CONFIG_CGROUP_WRITEBACK

@@ -300,10 +255,6 @@ struct mem_cgroup {
 	struct memcg_cgwb_frn cgwb_frn[MEMCG_CGWB_FRN_CNT];
 #endif
 
-	/* List of events which userspace want to receive */
-	struct list_head event_list;
-	spinlock_t event_list_lock;
-
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 	struct deferred_split deferred_split_queue;
 #endif

@@ -313,6 +264,58 @@ struct mem_cgroup {
 	struct lru_gen_mm_list mm_list;
 #endif
 
+#ifdef CONFIG_MEMCG_V1
+	/* Legacy consumer-oriented counters */
+	struct page_counter kmem;		/* v1 only */
+	struct page_counter tcpmem;		/* v1 only */
+
+	unsigned long soft_limit;
+
+	/* protected by memcg_oom_lock */
+	bool oom_lock;
+	int under_oom;
+
+	/* OOM-Killer disable */
+	int oom_kill_disable;
+
+	/* protect arrays of thresholds */
+	struct mutex thresholds_lock;
+
+	/* thresholds for memory usage. RCU-protected */
+	struct mem_cgroup_thresholds thresholds;
+
+	/* thresholds for mem+swap usage. RCU-protected */
+	struct mem_cgroup_thresholds memsw_thresholds;
+
+	/* For oom notifier event fd */
+	struct list_head oom_notify;
+
+	/*
+	 * Should we move charges of a task when a task is moved into this
+	 * mem_cgroup ? And what type of charges should we move ?
+	 */
+	unsigned long move_charge_at_immigrate;
+	/* taken only while moving_account > 0 */
+	spinlock_t move_lock;
+	unsigned long move_lock_flags;
+
+	/* Legacy tcp memory accounting */
+	bool tcpmem_active;
+	int tcpmem_pressure;
+
+	CACHELINE_PADDING(_pad2_);
+
+	/*
+	 * set > 0 if pages under this cgroup are moving to other cgroup.
+	 */
+	atomic_t moving_account;
+	struct task_struct *move_lock_task;
+
+	/* List of events which userspace want to receive */
+	struct list_head event_list;
+	spinlock_t event_list_lock;
+#endif /* CONFIG_MEMCG_V1 */
+
 	struct mem_cgroup_per_node *nodeinfo[];
 };

Signature · 1 line

2.45.2.803.g4e1b14247a-goog

Shakeel Butt

maintainer

2024-06-29 00:49 UTC #12 lore raw

Re: [PATCH v1 6/9] mm: memcg: put memcg1-specific struct mem_cgroup's members under CONFIG_MEMCG_V1

Quoted 64 lines · Roman Gushchin

Put memcg1-specific members of struct mem_cgroup under the CONFIG_MEMCG_V1 config option. Also group them close to the end of struct mem_cgroup just before the dynamic per-node part.

Signed-off-by Roman Gushchin <[email protected]>

---
 include/linux/memcontrol.h | 103 +++++++++++++++++++------------------
 1 file changed, 53 insertions(+), 50 deletions(-)

include/linux/memcontrol.h +1 ~~-25~~

index 44ab6394c9ed..107b0c5d6eab 100644
@@ -188,10 +188,6 @@ struct mem_cgroup {
 		struct page_counter memsw;	/* v1 only */
 	};
 
-	/* Legacy consumer-oriented counters */
-	struct page_counter kmem;		/* v1 only */
-	struct page_counter tcpmem;		/* v1 only */
-
 	/* Range enforcement for interrupt charges */
 	struct work_struct high_work;

@@ -205,8 +201,6 @@ struct mem_cgroup {
 	bool zswap_writeback;
 #endif
 
-	unsigned long soft_limit;
-
 	/* vmpressure notifications */
 	struct vmpressure vmpressure;

@@ -215,13 +209,7 @@ struct mem_cgroup {
 	 */
 	bool oom_group;
 
-	/* protected by memcg_oom_lock */
-	bool		oom_lock;
-	int		under_oom;
-
-	int	swappiness;
-	/* OOM-Killer disable */
-	int		oom_kill_disable;
+	int swappiness;
 
 	/* memory.events and memory.events.local */
 	struct cgroup_file events_file;

@@ -230,27 +218,6 @@ struct mem_cgroup {
 	/* handle for "memory.swap.events" */
 	struct cgroup_file swap_events_file;
 
-	/* protect arrays of thresholds */
-	struct mutex thresholds_lock;
-
-	/* thresholds for memory usage. RCU-protected */
-	struct mem_cgroup_thresholds thresholds;
-
-	/* thresholds for mem+swap usage. RCU-protected */
-	struct mem_cgroup_thresholds memsw_thresholds;
-
-	/* For oom notifier event fd */
-	struct list_head oom_notify;
-

include/linux/memcontrol.h struct mem_cgroup { · line 221

Quoted 10 lines

include/linux/memcontrol.h +0 -9

-	/*
-	 * Should we move charges of a task when a task is moved into this
-	 * mem_cgroup ? And what type of charges should we move ?
-	 */
-	unsigned long move_charge_at_immigrate;
-	/* taken only while moving_account > 0 */
-	spinlock_t		move_lock;
-	unsigned long		move_lock_flags;
-
 	CACHELINE_PADDING(_pad1_);

Let's also remove these _pad1_ and also _pad2_ as well as this rearrangement nullifies the reasons behind these paddings. We need to run some perf benchmarks to identify the newer false cache sharing ields.

Andrew Morton

maintainer

2024-07-04 23:35 UTC #13 lore raw

Re: [PATCH v1 6/9] mm: memcg: put memcg1-specific struct mem_cgroup's members under CONFIG_MEMCG_V1

Quoted 10 lines · On Fri, 28 Jun 2024 17:48:54 -0700 Shakeel Butt <[email protected]> wrote:

Quoted 10 lines

include/linux/memcontrol.h +0 ~~-10~~

-	/* For oom notifier event fd */
-	struct list_head oom_notify;
-
-	/*
-	 * Should we move charges of a task when a task is moved into this
-	 * mem_cgroup ? And what type of charges should we move ?
-	 */
-	unsigned long move_charge_at_immigrate;
-	/* taken only while moving_account > 0 */
-	spinlock_t		move_lock;

Quoted 8 lines

include/linux/memcontrol.h struct mem_cgroup { · line 221
Quoted 3 lines
include/linux/memcontrol.h +0 -2
-	unsigned long		move_lock_flags;
-
 	CACHELINE_PADDING(_pad1_);
Let's also remove these _pad1_ and also _pad2_ as well as this rearrangement nullifies the reasons behind these paddings. We need to run some perf benchmarks to identify the newer false cache sharing ields.

I guess this is going to be a followup patch (please).

Shakeel Butt

2024-07-05 03:43 UTC #14 lore raw

Re: [PATCH v1 6/9] mm: memcg: put memcg1-specific struct mem_cgroup's members under CONFIG_MEMCG_V1

Quoted 22 lines · Andrew Morton

Quoted 10 lines · On Fri, 28 Jun 2024 17:48:54 -0700 Shakeel Butt <[email protected]> wrote:
Quoted 10 lines
include/linux/memcontrol.h +0 ~~-10~~
-   /* For oom notifier event fd */
-   struct list_head oom_notify;
-
-   /*
-    * Should we move charges of a task when a task is moved into this
-    * mem_cgroup ? And what type of charges should we move ?
-    */
-   unsigned long move_charge_at_immigrate;
-   /* taken only while moving_account > 0 */
-   spinlock_t              move_lock;
Quoted 8 lines
include/linux/memcontrol.h struct mem_cgroup { · line 221
Quoted 3 lines
include/linux/memcontrol.h +0 -2
-   unsigned long           move_lock_flags;
-
    CACHELINE_PADDING(_pad1_);
Let's also remove these _pad1_ and also _pad2_ as well as this rearrangement nullifies the reasons behind these paddings. We need to run some perf benchmarks to identify the newer false cache sharing ields.

Quoted 1 line

I guess this is going to be a followup patch (please).

Already posted [1] and has been picked.

[1] https://lore.kernel.org/linux-mm/[email protected]/

Shakeel Butt

maintainer Acked-by on v1 6/9

2024-07-03 15:12 UTC #15 lore raw

Re: [PATCH v1 6/9] mm: memcg: put memcg1-specific struct mem_cgroup's members under CONFIG_MEMCG_V1

In reply to Roman Gushchin

Quoted 5 lines · Roman Gushchin

Put memcg1-specific members of struct mem_cgroup under the CONFIG_MEMCG_V1 config option. Also group them close to the end of struct mem_cgroup just before the dynamic per-node part.
Signed-off-by Roman Gushchin <[email protected]>

Acked-by Shakeel Butt <[email protected]>

Roman Gushchin

author maintainer

2024-06-28 21:04 UTC #16 lore raw

PATCH 7/9 mm: memcg: guard memcg1-specific members of struct mem_cgroup_per_node

In reply to Roman Gushchin

Put memcg1-specific members of struct mem_cgroup_per_node under the CONFIG_MEMCG_V1 config option.

Signed-off-by Roman Gushchin <[email protected]>

---
 include/linux/memcontrol.h | 2 ++
 1 file changed, 2 insertions(+)

include/linux/memcontrol.h +2 -0

index 107b0c5d6eab..c7ef628ee882 100644
@@ -92,6 +92,7 @@ struct mem_cgroup_per_node {
 	struct lruvec_stats			*lruvec_stats;
 	struct shrinker_info __rcu	*shrinker_info;
 
+#ifdef CONFIG_MEMCG_V1
 	/*
 	 * Memcg-v1 only stuff in middle as buffer between read mostly fields
 	 * and update often fields to avoid false sharing. Once v1 stuff is

@@ -102,6 +103,7 @@ struct mem_cgroup_per_node {
 	unsigned long		usage_in_excess;/* Set to the value by which */
 						/* the soft limit is exceeded*/
 	bool			on_tree;
+#endif
 
 	/* Fields which get updated often at the end. */
 	struct lruvec		lruvec;

Signature · 1 line

2.45.2.803.g4e1b14247a-goog

Shakeel Butt

maintainer

2024-06-29 00:52 UTC #17 lore raw

Re: [PATCH v1 7/9] mm: memcg: guard memcg1-specific members of struct mem_cgroup_per_node

Quoted 21 lines · Roman Gushchin

Put memcg1-specific members of struct mem_cgroup_per_node under the CONFIG_MEMCG_V1 config option.

Signed-off-by Roman Gushchin <[email protected]>

---
 include/linux/memcontrol.h | 2 ++
 1 file changed, 2 insertions(+)

include/linux/memcontrol.h +1 -0

index 107b0c5d6eab..c7ef628ee882 100644
@@ -92,6 +92,7 @@ struct mem_cgroup_per_node {
 	struct lruvec_stats			*lruvec_stats;
 	struct shrinker_info __rcu	*shrinker_info;
 
+#ifdef CONFIG_MEMCG_V1
 	/*
 	 * Memcg-v1 only stuff in middle as buffer between read mostly fields
 	 * and update often fields to avoid false sharing. Once v1 stuff is

include/linux/memcontrol.h struct mem_cgroup_per_node { · line 105

Quoted 3 lines

include/linux/memcontrol.h +0 -0

@@ -102,6 +103,7 @@ struct mem_cgroup_per_node {
 	unsigned long		usage_in_excess;/* Set to the value by which */
 						/* the soft limit is exceeded*/
 	bool			on_tree;

Here we definitely need a padding after the pointers and before the lruvec. We can add a #else to the #ifdef CONFIG_MEMCG_V1 and put a cacheline padding in it.

Quoted 7 lines

include/linux/memcontrol.h +1 -0

+#endif
 
 	/* Fields which get updated often at the end. */
 	struct lruvec		lruvec;

Signature · 1 line

2.45.2.803.g4e1b14247a-goog

Shakeel Butt

maintainer Acked-by on v1 7/9

2024-07-03 15:13 UTC #18 lore raw

Re: [PATCH v1 7/9] mm: memcg: guard memcg1-specific members of struct mem_cgroup_per_node

In reply to Roman Gushchin

Quoted 4 lines · Roman Gushchin

Put memcg1-specific members of struct mem_cgroup_per_node under the CONFIG_MEMCG_V1 config option.
Signed-off-by Roman Gushchin <[email protected]>

Acked-by Shakeel Butt <[email protected]>

Roman Gushchin

author maintainer

2024-06-28 21:04 UTC #19 lore raw

PATCH 8/9 mm: memcg: put struct task_struct::memcg_in_oom under CONFIG_MEMCG_V1

In reply to Roman Gushchin

The memcg_in_oom field of the struct task_struct is not used by the cgroup v2's memory controller, so it can be happily compiled out if CONFIG_MEMCG_V1 is not set.

Signed-off-by Roman Gushchin <[email protected]>

---
 include/linux/sched.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

include/linux/sched.h +3 -1

index 61591ac6eab6..2a16023e8620 100644
@@ -1447,9 +1447,11 @@ struct task_struct {
 	unsigned int			kcov_softirq;
 #endif
 
-#ifdef CONFIG_MEMCG
+#ifdef CONFIG_MEMCG_V1
 	struct mem_cgroup		*memcg_in_oom;
+#endif
 
+#ifdef CONFIG_MEMCG
 	/* Number of pages to reclaim on returning to userland: */
 	unsigned int			memcg_nr_pages_over_high;

Signature · 1 line

2.45.2.803.g4e1b14247a-goog

Shakeel Butt

maintainer Acked-by on v1 8/9

2024-06-29 00:53 UTC #20 lore raw

Re: [PATCH v1 8/9] mm: memcg: put struct task_struct::memcg_in_oom under CONFIG_MEMCG_V1

Quoted 5 lines · Roman Gushchin

The memcg_in_oom field of the struct task_struct is not used by the cgroup v2's memory controller, so it can be happily compiled out if CONFIG_MEMCG_V1 is not set.
Signed-off-by Roman Gushchin <[email protected]>

Acked-by Shakeel Butt <[email protected]>

Roman Gushchin

author maintainer

2024-06-28 21:04 UTC #21 lore raw

PATCH 9/9 mm: memcg: put struct task_struct::in_user_fault under CONFIG_MEMCG_V1

In reply to Roman Gushchin

The struct task_struct's in_user_fault member is not used by the cgroup v2's memory controller, so it can be put under the CONFIG_MEMCG_V1 config option. To do so, mem_cgroup_enter_user_fault() and mem_cgroup_exit_user_fault() are moved under the CONFIG_MEMCG_V1 option as well.

Signed-off-by Roman Gushchin <[email protected]>

---
 include/linux/memcontrol.h | 40 +++++++++++++++++++-------------------
 include/linux/sched.h      |  2 +-
 2 files changed, 21 insertions(+), 21 deletions(-)

include/linux/memcontrol.h +20 ~~-20~~

index c7ef628ee882..d0c9365ff039 100644
@@ -943,18 +943,6 @@ void mem_cgroup_print_oom_context(struct mem_cgroup *memcg,
 
 void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg);
 
-static inline void mem_cgroup_enter_user_fault(void)
-{
-	WARN_ON(current->in_user_fault);
-	current->in_user_fault = 1;
-}
-
-static inline void mem_cgroup_exit_user_fault(void)
-{
-	WARN_ON(!current->in_user_fault);
-	current->in_user_fault = 0;
-}
-
 struct mem_cgroup *mem_cgroup_get_oom_group(struct task_struct *victim,
 					    struct mem_cgroup *oom_domain);
 void mem_cgroup_print_oom_group(struct mem_cgroup *memcg);

@@ -1402,14 +1390,6 @@ static inline void mem_cgroup_handle_over_high(gfp_t gfp_mask)
 {
 }
 
-static inline void mem_cgroup_enter_user_fault(void)
-{
-}
-
-static inline void mem_cgroup_exit_user_fault(void)
-{
-}
-
 static inline struct mem_cgroup *mem_cgroup_get_oom_group(
 	struct task_struct *victim, struct mem_cgroup *oom_domain)
 {

@@ -1890,6 +1870,18 @@ static inline void mem_cgroup_unlock_pages(void)
 	rcu_read_unlock();
 }
 
+static inline void mem_cgroup_enter_user_fault(void)
+{
+	WARN_ON(current->in_user_fault);
+	current->in_user_fault = 1;
+}
+
+static inline void mem_cgroup_exit_user_fault(void)
+{
+	WARN_ON(!current->in_user_fault);
+	current->in_user_fault = 0;
+}
+
 #else /* CONFIG_MEMCG_V1 */
 static inline
 unsigned long memcg1_soft_limit_reclaim(pg_data_t *pgdat, int order,

@@ -1929,6 +1921,14 @@ static inline bool mem_cgroup_oom_synchronize(bool wait)
 	return false;
 }
 
+static inline void mem_cgroup_enter_user_fault(void)
+{
+}
+
+static inline void mem_cgroup_exit_user_fault(void)
+{
+}
+
 #endif /* CONFIG_MEMCG_V1 */
 
 #endif /* _LINUX_MEMCONTROL_H */

include/linux/sched.h +1 -1

index 2a16023e8620..a7770c566c4d 100644
@@ -934,7 +934,7 @@ struct task_struct {
 #ifndef TIF_RESTORE_SIGMASK
 	unsigned			restore_sigmask:1;
 #endif
-#ifdef CONFIG_MEMCG
+#ifdef CONFIG_MEMCG_V1
 	unsigned			in_user_fault:1;
 #endif
 #ifdef CONFIG_LRU_GEN

Signature · 1 line

2.45.2.803.g4e1b14247a-goog

Shakeel Butt

maintainer Acked-by on v1 9/9

2024-06-29 00:55 UTC #22 lore raw

Re: [PATCH v1 9/9] mm: memcg: put struct task_struct::in_user_fault under CONFIG_MEMCG_V1

Quoted 7 lines · Roman Gushchin

The struct task_struct's in_user_fault member is not used by the cgroup v2's memory controller, so it can be put under the CONFIG_MEMCG_V1 config option. To do so, mem_cgroup_enter_user_fault() and mem_cgroup_exit_user_fault() are moved under the CONFIG_MEMCG_V1 option as well.
Signed-off-by Roman Gushchin <[email protected]>

Acked-by Shakeel Butt <[email protected]>