From: Roman Gushchin <guro@fb.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>,
Shakeel Butt <shakeelb@google.com>, <linux-mm@kvack.org>,
Vlastimil Babka <vbabka@suse.cz>, <kernel-team@fb.com>,
<linux-kernel@vger.kernel.org>, Roman Gushchin <guro@fb.com>
Subject: [PATCH v4 07/19] mm: memcg/slab: allocate obj_cgroups for non-root slab pages
Date: Tue, 26 May 2020 14:42:15 -0700 [thread overview]
Message-ID: <20200526214227.989341-8-guro@fb.com> (raw)
In-Reply-To: <20200526214227.989341-1-guro@fb.com>
Allocate and release memory to store obj_cgroup pointers for each
non-root slab page. Reuse page->mem_cgroup pointer to store a pointer
to the allocated space.
To distinguish between obj_cgroups and memcg pointers in case
when it's not obvious which one is used (as in page_cgroup_ino()),
let's always set the lowest bit in the obj_cgroup case.
Signed-off-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
---
include/linux/mm_types.h | 5 +++-
include/linux/slab_def.h | 6 +++++
include/linux/slub_def.h | 5 ++++
mm/memcontrol.c | 17 +++++++++++---
mm/slab.h | 49 ++++++++++++++++++++++++++++++++++++++++
5 files changed, 78 insertions(+), 4 deletions(-)
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 64ede5f150dc..0277fbab7c93 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -198,7 +198,10 @@ struct page {
atomic_t _refcount;
#ifdef CONFIG_MEMCG
- struct mem_cgroup *mem_cgroup;
+ union {
+ struct mem_cgroup *mem_cgroup;
+ struct obj_cgroup **obj_cgroups;
+ };
#endif
/*
diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
index abc7de77b988..ccda7b9669a5 100644
--- a/include/linux/slab_def.h
+++ b/include/linux/slab_def.h
@@ -114,4 +114,10 @@ static inline unsigned int obj_to_index(const struct kmem_cache *cache,
return reciprocal_divide(offset, cache->reciprocal_buffer_size);
}
+static inline int objs_per_slab_page(const struct kmem_cache *cache,
+ const struct page *page)
+{
+ return cache->num;
+}
+
#endif /* _LINUX_SLAB_DEF_H */
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index 30e91c83d401..f87302dcfe8c 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -198,4 +198,9 @@ static inline unsigned int obj_to_index(const struct kmem_cache *cache,
return __obj_to_index(cache, page_address(page), obj);
}
+static inline int objs_per_slab_page(const struct kmem_cache *cache,
+ const struct page *page)
+{
+ return page->objects;
+}
#endif /* _LINUX_SLUB_DEF_H */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 7d4cbd594b83..c0f1abfea30e 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -569,10 +569,21 @@ ino_t page_cgroup_ino(struct page *page)
unsigned long ino = 0;
rcu_read_lock();
- if (PageSlab(page) && !PageTail(page))
+ if (PageSlab(page) && !PageTail(page)) {
memcg = memcg_from_slab_page(page);
- else
- memcg = READ_ONCE(page->mem_cgroup);
+ } else {
+ memcg = page->mem_cgroup;
+
+ /*
+ * The lowest bit set means that memcg isn't a valid
+ * memcg pointer, but a obj_cgroups pointer.
+ * In this case the page is shared and doesn't belong
+ * to any specific memory cgroup.
+ */
+ if ((unsigned long) memcg & 0x1UL)
+ memcg = NULL;
+ }
+
while (memcg && !(memcg->css.flags & CSS_ONLINE))
memcg = parent_mem_cgroup(memcg);
if (memcg)
diff --git a/mm/slab.h b/mm/slab.h
index 8a574d9361c1..a1633ea15fbf 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -319,6 +319,18 @@ static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
return s->memcg_params.root_cache;
}
+static inline struct obj_cgroup **page_obj_cgroups(struct page *page)
+{
+ /*
+ * page->mem_cgroup and page->obj_cgroups are sharing the same
+ * space. To distinguish between them in case we don't know for sure
+ * that the page is a slab page (e.g. page_cgroup_ino()), let's
+ * always set the lowest bit of obj_cgroups.
+ */
+ return (struct obj_cgroup **)
+ ((unsigned long)page->obj_cgroups & ~0x1UL);
+}
+
/*
* Expects a pointer to a slab page. Please note, that PageSlab() check
* isn't sufficient, as it returns true also for tail compound slab pages,
@@ -406,6 +418,26 @@ static __always_inline void memcg_uncharge_slab(struct page *page, int order,
percpu_ref_put_many(&s->memcg_params.refcnt, nr_pages);
}
+static inline int memcg_alloc_page_obj_cgroups(struct page *page,
+ struct kmem_cache *s, gfp_t gfp)
+{
+ unsigned int objects = objs_per_slab_page(s, page);
+ void *vec;
+
+ vec = kcalloc(objects, sizeof(struct obj_cgroup *), gfp);
+ if (!vec)
+ return -ENOMEM;
+
+ page->obj_cgroups = (struct obj_cgroup **) ((unsigned long)vec | 0x1UL);
+ return 0;
+}
+
+static inline void memcg_free_page_obj_cgroups(struct page *page)
+{
+ kfree(page_obj_cgroups(page));
+ page->obj_cgroups = NULL;
+}
+
extern void slab_init_memcg_params(struct kmem_cache *);
extern void memcg_link_cache(struct kmem_cache *s, struct mem_cgroup *memcg);
@@ -455,6 +487,16 @@ static inline void memcg_uncharge_slab(struct page *page, int order,
{
}
+static inline int memcg_alloc_page_obj_cgroups(struct page *page,
+ struct kmem_cache *s, gfp_t gfp)
+{
+ return 0;
+}
+
+static inline void memcg_free_page_obj_cgroups(struct page *page)
+{
+}
+
static inline void slab_init_memcg_params(struct kmem_cache *s)
{
}
@@ -481,12 +523,18 @@ static __always_inline int charge_slab_page(struct page *page,
gfp_t gfp, int order,
struct kmem_cache *s)
{
+ int ret;
+
if (is_root_cache(s)) {
mod_node_page_state(page_pgdat(page), cache_vmstat_idx(s),
PAGE_SIZE << order);
return 0;
}
+ ret = memcg_alloc_page_obj_cgroups(page, s, gfp);
+ if (ret)
+ return ret;
+
return memcg_charge_slab(page, gfp, order, s);
}
@@ -499,6 +547,7 @@ static __always_inline void uncharge_slab_page(struct page *page, int order,
return;
}
+ memcg_free_page_obj_cgroups(page);
memcg_uncharge_slab(page, order, s);
}
--
2.25.4
next prev parent reply other threads:[~2020-05-26 21:43 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-26 21:42 [PATCH v4 00/19] The new cgroup slab memory controller Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 01/19] mm: memcg: factor out memcg- and lruvec-level changes out of __mod_lruvec_state() Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 02/19] mm: memcg: prepare for byte-sized vmstat items Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 03/19] mm: memcg: convert vmstat slab counters to bytes Roman Gushchin
2020-05-27 11:43 ` Vlastimil Babka
2020-05-27 16:25 ` Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 04/19] mm: slub: implement SLUB version of obj_to_index() Roman Gushchin
2020-05-27 19:44 ` Johannes Weiner
2020-05-26 21:42 ` [PATCH v4 05/19] mm: memcontrol: decouple reference counting from page accounting Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 06/19] mm: memcg/slab: obj_cgroup API Roman Gushchin
2020-05-27 19:56 ` Johannes Weiner
2020-05-27 20:03 ` Roman Gushchin
2020-05-26 21:42 ` Roman Gushchin [this message]
2020-05-26 21:42 ` [PATCH v4 08/19] mm: memcg/slab: save obj_cgroup for non-root slab objects Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 09/19] mm: memcg/slab: charge individual slab objects instead of pages Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 10/19] mm: memcg/slab: deprecate memory.kmem.slabinfo Roman Gushchin
2020-05-27 15:54 ` Vlastimil Babka
2020-05-27 16:28 ` Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 11/19] mm: memcg/slab: move memcg_kmem_bypass() to memcontrol.h Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 12/19] mm: memcg/slab: use a single set of kmem_caches for all accounted allocations Roman Gushchin
2020-05-27 16:01 ` Vlastimil Babka
2020-05-27 16:29 ` Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 13/19] mm: memcg/slab: simplify memcg cache creation Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 14/19] mm: memcg/slab: remove memcg_kmem_get_cache() Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 15/19] mm: memcg/slab: deprecate slab_root_caches Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 16/19] mm: memcg/slab: remove redundant check in memcg_accumulate_slabinfo() Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 17/19] mm: memcg/slab: use a single set of kmem_caches for all allocations Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 18/19] kselftests: cgroup: add kernel memory accounting tests Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 19/19] tools/cgroup: add memcg_slabinfo.py tool Roman Gushchin
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