[PATCH] memcg: localize memcg_kmem_enabled() check

From: Shakeel Butt
Date: Wed Jan 02 2019 - 19:31:38 EST


Move the memcg_kmem_enabled() checks into memcg kmem charge/uncharge
functions, so, the users don't have to explicitly check that condition.
This is purely code cleanup patch without any functional change. Only
the order of checks in memcg_charge_slab() can potentially be changed
but the functionally it will be same. This should not matter as
memcg_charge_slab() is not in the hot path.

Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
---
fs/pipe.c | 3 +--
include/linux/memcontrol.h | 28 ++++++++++++++++++++++++----
mm/memcontrol.c | 16 ++++++++--------
mm/page_alloc.c | 4 ++--
mm/slab.h | 4 ----
5 files changed, 35 insertions(+), 20 deletions(-)

diff --git a/fs/pipe.c b/fs/pipe.c
index bdc5d3c0977d..51d5fd8840ab 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -140,8 +140,7 @@ static int anon_pipe_buf_steal(struct pipe_inode_info *pipe,
struct page *page = buf->page;

if (page_count(page) == 1) {
- if (memcg_kmem_enabled())
- memcg_kmem_uncharge(page, 0);
+ memcg_kmem_uncharge(page, 0);
__SetPageLocked(page);
return 0;
}
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 83ae11cbd12c..e264d5c28781 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1273,12 +1273,12 @@ static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)

struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep);
void memcg_kmem_put_cache(struct kmem_cache *cachep);
-int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
- struct mem_cgroup *memcg);

#ifdef CONFIG_MEMCG_KMEM
-int memcg_kmem_charge(struct page *page, gfp_t gfp, int order);
-void memcg_kmem_uncharge(struct page *page, int order);
+int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order);
+void __memcg_kmem_uncharge(struct page *page, int order);
+int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
+ struct mem_cgroup *memcg);

extern struct static_key_false memcg_kmem_enabled_key;
extern struct workqueue_struct *memcg_kmem_cache_wq;
@@ -1300,6 +1300,26 @@ static inline bool memcg_kmem_enabled(void)
return static_branch_unlikely(&memcg_kmem_enabled_key);
}

+static inline int memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
+{
+ if (memcg_kmem_enabled())
+ return __memcg_kmem_charge(page, gfp, order);
+ return 0;
+}
+
+static inline void memcg_kmem_uncharge(struct page *page, int order)
+{
+ if (memcg_kmem_enabled())
+ __memcg_kmem_uncharge(page, order);
+}
+
+static inline int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp,
+ int order, struct mem_cgroup *memcg)
+{
+ if (memcg_kmem_enabled())
+ return __memcg_kmem_charge_memcg(page, gfp, order, memcg);
+ return 0;
+}
/*
* helper for accessing a memcg's index. It will be used as an index in the
* child cache array in kmem_cache, and also to derive its name. This function
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 4afd5971f2d4..e8ca09920d71 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2557,7 +2557,7 @@ void memcg_kmem_put_cache(struct kmem_cache *cachep)
}

/**
- * memcg_kmem_charge_memcg: charge a kmem page
+ * __memcg_kmem_charge_memcg: charge a kmem page
* @page: page to charge
* @gfp: reclaim mode
* @order: allocation order
@@ -2565,7 +2565,7 @@ void memcg_kmem_put_cache(struct kmem_cache *cachep)
*
* Returns 0 on success, an error code on failure.
*/
-int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
+int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
struct mem_cgroup *memcg)
{
unsigned int nr_pages = 1 << order;
@@ -2588,24 +2588,24 @@ int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
}

/**
- * memcg_kmem_charge: charge a kmem page to the current memory cgroup
+ * __memcg_kmem_charge: charge a kmem page to the current memory cgroup
* @page: page to charge
* @gfp: reclaim mode
* @order: allocation order
*
* Returns 0 on success, an error code on failure.
*/
-int memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
+int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
{
struct mem_cgroup *memcg;
int ret = 0;

- if (mem_cgroup_disabled() || memcg_kmem_bypass())
+ if (memcg_kmem_bypass())
return 0;

memcg = get_mem_cgroup_from_current();
if (!mem_cgroup_is_root(memcg)) {
- ret = memcg_kmem_charge_memcg(page, gfp, order, memcg);
+ ret = __memcg_kmem_charge_memcg(page, gfp, order, memcg);
if (!ret)
__SetPageKmemcg(page);
}
@@ -2613,11 +2613,11 @@ int memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
return ret;
}
/**
- * memcg_kmem_uncharge: uncharge a kmem page
+ * __memcg_kmem_uncharge: uncharge a kmem page
* @page: page to uncharge
* @order: allocation order
*/
-void memcg_kmem_uncharge(struct page *page, int order)
+void __memcg_kmem_uncharge(struct page *page, int order)
{
struct mem_cgroup *memcg = page->mem_cgroup;
unsigned int nr_pages = 1 << order;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0634fbdef078..d65c337d2257 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1053,7 +1053,7 @@ static __always_inline bool free_pages_prepare(struct page *page,
if (PageMappingFlags(page))
page->mapping = NULL;
if (memcg_kmem_enabled() && PageKmemcg(page))
- memcg_kmem_uncharge(page, order);
+ __memcg_kmem_uncharge(page, order);
if (check_free)
bad += free_pages_check(page);
if (bad)
@@ -4667,7 +4667,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid,

out:
if (memcg_kmem_enabled() && (gfp_mask & __GFP_ACCOUNT) && page &&
- unlikely(memcg_kmem_charge(page, gfp_mask, order) != 0)) {
+ unlikely(__memcg_kmem_charge(page, gfp_mask, order) != 0)) {
__free_pages(page, order);
page = NULL;
}
diff --git a/mm/slab.h b/mm/slab.h
index 4190c24ef0e9..cde51d7f631f 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -276,8 +276,6 @@ static __always_inline int memcg_charge_slab(struct page *page,
gfp_t gfp, int order,
struct kmem_cache *s)
{
- if (!memcg_kmem_enabled())
- return 0;
if (is_root_cache(s))
return 0;
return memcg_kmem_charge_memcg(page, gfp, order, s->memcg_params.memcg);
@@ -286,8 +284,6 @@ static __always_inline int memcg_charge_slab(struct page *page,
static __always_inline void memcg_uncharge_slab(struct page *page, int order,
struct kmem_cache *s)
{
- if (!memcg_kmem_enabled())
- return;
memcg_kmem_uncharge(page, order);
}

--
2.20.1.415.g653613c723-goog