[PATCH 2/4] mm: memcontrol: reign in the CONFIG space madness
From: Johannes Weiner
Date: Fri Dec 11 2015 - 14:54:36 EST
What CONFIG_INET and CONFIG_LEGACY_KMEM guard inside the memory
controller code is insignificant, having these conditionals is not
worth the complication and fragility that comes with them.
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
---
include/linux/memcontrol.h | 14 +++++--------
init/Kconfig | 26 +++--------------------
mm/memcontrol.c | 52 +++-------------------------------------------
mm/vmpressure.c | 2 --
4 files changed, 11 insertions(+), 83 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 2bb14d02..47995b4 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -233,9 +233,11 @@ struct mem_cgroup {
*/
struct mem_cgroup_stat_cpu __percpu *stat;
-#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET)
+ unsigned long socket_pressure;
+
+ /* Legacy tcp memory accounting */
struct cg_proto tcp_mem;
-#endif
+
#ifndef CONFIG_SLOB
/* Index in the kmem_cache->memcg_params.memcg_caches array */
int kmemcg_id;
@@ -254,10 +256,6 @@ struct mem_cgroup {
struct wb_domain cgwb_domain;
#endif
-#ifdef CONFIG_INET
- unsigned long socket_pressure;
-#endif
-
/* List of events which userspace want to receive */
struct list_head event_list;
spinlock_t event_list_lock;
@@ -712,15 +710,13 @@ void sock_update_memcg(struct sock *sk);
void sock_release_memcg(struct sock *sk);
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 defined(CONFIG_MEMCG) && defined(CONFIG_INET)
+#ifdef CONFIG_MEMCG
extern struct static_key_false memcg_sockets_enabled_key;
#define mem_cgroup_sockets_enabled static_branch_unlikely(&memcg_sockets_enabled_key)
static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
{
-#ifdef CONFIG_MEMCG_LEGACY_KMEM
if (memcg->tcp_mem.memory_pressure)
return true;
-#endif
do {
if (time_before(jiffies, memcg->socket_pressure))
return true;
diff --git a/init/Kconfig b/init/Kconfig
index e8cdf02..b8fe7586 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1057,25 +1057,6 @@ config MEMCG_SWAP_ENABLED
For those who want to have the feature enabled by default should
select this option (if, for some reason, they need to disable it
then swapaccount=0 does the trick).
-config MEMCG_LEGACY_KMEM
- bool
-config MEMCG_KMEM
- bool "Legacy Memory Resource Controller Kernel Memory accounting"
- depends on MEMCG
- depends on SLUB || SLAB
- select MEMCG_LEGACY_KMEM
- help
- The Kernel Memory extension for Memory Resource Controller can limit
- the amount of memory used by kernel objects in the system. Those are
- fundamentally different from the entities handled by the standard
- Memory Controller, which are page-based, and can be swapped. Users of
- the kmem extension can use it to guarantee that no group of processes
- will ever exhaust kernel resources alone.
-
- This option affects the ORIGINAL cgroup interface. The cgroup2 memory
- controller includes important in-kernel memory consumers per default.
-
- If you're using cgroup2, say N.
config CGROUP_HUGETLB
bool "HugeTLB Resource Controller for Control Groups"
@@ -1225,10 +1206,9 @@ config USER_NS
to provide different user info for different servers.
When user namespaces are enabled in the kernel it is
- recommended that the MEMCG and MEMCG_KMEM options also be
- enabled and that user-space use the memory control groups to
- limit the amount of memory a memory unprivileged users can
- use.
+ recommended that the MEMCG option also be enabled and that
+ user-space use the memory control groups to limit the amount
+ of memory a memory unprivileged users can use.
If unsure, say N.
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 5cf7fd2..422ff3f 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2821,11 +2821,9 @@ static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css,
case _KMEM:
counter = &memcg->kmem;
break;
-#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET)
case _TCP:
counter = &memcg->tcp_mem.memory_allocated;
break;
-#endif
default:
BUG();
}
@@ -2985,7 +2983,6 @@ static void memcg_free_kmem(struct mem_cgroup *memcg)
}
#endif /* !CONFIG_SLOB */
-#ifdef CONFIG_MEMCG_LEGACY_KMEM
static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
unsigned long limit)
{
@@ -3003,16 +3000,7 @@ out:
mutex_unlock(&memcg_limit_mutex);
return ret;
}
-#else
-static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
- unsigned long limit)
-{
- return -EINVAL;
-}
-#endif /* CONFIG_MEMCG_LEGACY_KMEM */
-
-#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET)
static int memcg_update_tcp_limit(struct mem_cgroup *memcg, unsigned long limit)
{
int ret;
@@ -3047,12 +3035,6 @@ out:
mutex_unlock(&memcg_limit_mutex);
return ret;
}
-#else
-static int memcg_update_tcp_limit(struct mem_cgroup *memcg, unsigned long limit)
-{
- return -EINVAL;
-}
-#endif /* CONFIG_MEMCG_LEGACY_KMEM && CONFIG_INET */
/*
* The user of this function is...
@@ -3115,11 +3097,9 @@ static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf,
case _KMEM:
counter = &memcg->kmem;
break;
-#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET)
case _TCP:
counter = &memcg->tcp_mem.memory_allocated;
break;
-#endif
default:
BUG();
}
@@ -4072,7 +4052,6 @@ static struct cftype mem_cgroup_legacy_files[] = {
.seq_show = memcg_numa_stat_show,
},
#endif
-#ifdef CONFIG_MEMCG_LEGACY_KMEM
{
.name = "kmem.limit_in_bytes",
.private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT),
@@ -4105,7 +4084,6 @@ static struct cftype mem_cgroup_legacy_files[] = {
.seq_show = memcg_slab_show,
},
#endif
-#ifdef CONFIG_INET
{
.name = "kmem.tcp.limit_in_bytes",
.private = MEMFILE_PRIVATE(_TCP, RES_LIMIT),
@@ -4129,8 +4107,6 @@ static struct cftype mem_cgroup_legacy_files[] = {
.write = mem_cgroup_reset,
.read_u64 = mem_cgroup_read_u64,
},
-#endif
-#endif
{ }, /* terminate */
};
@@ -4258,15 +4234,13 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
vmpressure_init(&memcg->vmpressure);
INIT_LIST_HEAD(&memcg->event_list);
spin_lock_init(&memcg->event_list_lock);
+ memcg->socket_pressure = jiffies;
#ifndef CONFIG_SLOB
memcg->kmemcg_id = -1;
#endif
#ifdef CONFIG_CGROUP_WRITEBACK
INIT_LIST_HEAD(&memcg->cgwb_list);
#endif
-#ifdef CONFIG_INET
- memcg->socket_pressure = jiffies;
-#endif
return &memcg->css;
free_out:
@@ -4299,10 +4273,8 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
memcg->soft_limit = PAGE_COUNTER_MAX;
page_counter_init(&memcg->memsw, &parent->memsw);
page_counter_init(&memcg->kmem, &parent->kmem);
-#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET)
page_counter_init(&memcg->tcp_mem.memory_allocated,
&parent->tcp_mem.memory_allocated);
-#endif
/*
* No need to take a reference to the parent because cgroup
@@ -4314,9 +4286,7 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
memcg->soft_limit = PAGE_COUNTER_MAX;
page_counter_init(&memcg->memsw, NULL);
page_counter_init(&memcg->kmem, NULL);
-#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET)
page_counter_init(&memcg->tcp_mem.memory_allocated, NULL);
-#endif
/*
* Deeper hierachy with use_hierarchy == false doesn't make
* much sense so let cgroup subsystem know about this
@@ -4331,10 +4301,8 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
if (ret)
return ret;
-#ifdef CONFIG_INET
if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
static_branch_inc(&memcg_sockets_enabled_key);
-#endif
/*
* Make sure the memcg is initialized: mem_cgroup_iter()
@@ -4374,17 +4342,11 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
{
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
-#ifdef CONFIG_INET
if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
static_branch_dec(&memcg_sockets_enabled_key);
-#endif
-
- memcg_free_kmem(memcg);
-#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET)
if (memcg->tcp_mem.active)
static_branch_dec(&memcg_sockets_enabled_key);
-#endif
memcg_free_kmem(memcg);
@@ -5585,8 +5547,6 @@ void mem_cgroup_replace_page(struct page *oldpage, struct page *newpage)
commit_charge(newpage, memcg, true);
}
-#ifdef CONFIG_INET
-
DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key);
EXPORT_SYMBOL(memcg_sockets_enabled_key);
@@ -5612,10 +5572,8 @@ void sock_update_memcg(struct sock *sk)
memcg = mem_cgroup_from_task(current);
if (memcg == root_mem_cgroup)
goto out;
-#ifdef CONFIG_MEMCG_LEGACY_KMEM
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !memcg->tcp_mem.active)
goto out;
-#endif
if (css_tryget_online(&memcg->css))
sk->sk_memcg = memcg;
out:
@@ -5641,7 +5599,6 @@ bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages)
{
gfp_t gfp_mask = GFP_KERNEL;
-#ifdef CONFIG_MEMCG_LEGACY_KMEM
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
struct page_counter *counter;
@@ -5654,7 +5611,7 @@ bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages)
memcg->tcp_mem.memory_pressure = 1;
return false;
}
-#endif
+
/* Don't block in the packet receive path */
if (in_softirq())
gfp_mask = GFP_NOWAIT;
@@ -5673,19 +5630,16 @@ 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_LEGACY_KMEM
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
page_counter_uncharge(&memcg->tcp_mem.memory_allocated,
nr_pages);
return;
}
-#endif
+
page_counter_uncharge(&memcg->memory, nr_pages);
css_put_many(&memcg->css, nr_pages);
}
-#endif /* CONFIG_INET */
-
static int __init cgroup_memory(char *s)
{
char *token;
diff --git a/mm/vmpressure.c b/mm/vmpressure.c
index 8cdeebe..506f03e 100644
--- a/mm/vmpressure.c
+++ b/mm/vmpressure.c
@@ -275,7 +275,6 @@ 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
@@ -287,7 +286,6 @@ void vmpressure(gfp_t gfp, struct mem_cgroup *memcg, bool tree,
*/
memcg->socket_pressure = jiffies + HZ;
}
-#endif
}
}
--
2.6.3
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