mm: memcg/slab: unify SLAB and SLUB page accounting

Currently the page accounting code is duplicated in SLAB and SLUB
internals.  Let's move it into new (un)charge_slab_page helpers in the
slab_common.c file.  These helpers will be responsible for statistics
(global and memcg-aware) and memcg charging.  So they are replacing direct
memcg_(un)charge_slab() calls.

Link: http://lkml.kernel.org/r/20190611231813.3148843-6-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Waiman Long <longman@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 30 insertions, 28 deletions

diff --git a/mm/slab.c b/mm/slab.c
index 30347bd3f19c..e9d90b0da47b 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1360,7 +1360,6 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
                                                                 int nodeid)
 {
         struct page *page;
-        int nr_pages;
 
         flags |= cachep->allocflags;
 
@@ -1370,17 +1369,11 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
                 return NULL;
         }
 
-        if (memcg_charge_slab(page, flags, cachep->gfporder, cachep)) {
+        if (charge_slab_page(page, flags, cachep->gfporder, cachep)) {
                 __free_pages(page, cachep->gfporder);
                 return NULL;
         }
 
-        nr_pages = (1 << cachep->gfporder);
-        if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
-                mod_lruvec_page_state(page, NR_SLAB_RECLAIMABLE, nr_pages);
-        else
-                mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE, nr_pages);
-
         __SetPageSlab(page);
         /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */
         if (sk_memalloc_socks() && page_is_pfmemalloc(page))
@@ -1395,12 +1388,6 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
 static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
 {
         int order = cachep->gfporder;
-        unsigned long nr_freed = (1 << order);
-
-        if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
-                mod_lruvec_page_state(page, NR_SLAB_RECLAIMABLE, -nr_freed);
-        else
-                mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE, -nr_freed);
 
         BUG_ON(!PageSlab(page));
         __ClearPageSlabPfmemalloc(page);
@@ -1409,8 +1396,8 @@ static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
         page->mapping = NULL;
 
         if (current->reclaim_state)
-                current->reclaim_state->reclaimed_slab += nr_freed;
-        memcg_uncharge_slab(page, order, cachep);
+                current->reclaim_state->reclaimed_slab += 1 << order;
+        uncharge_slab_page(page, order, cachep);
         __free_pages(page, order);
 }
 
diff --git a/mm/slab.h b/mm/slab.h
index dc83583ee9dd..46623a576a3c 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -205,6 +205,12 @@ ssize_t slabinfo_write(struct file *file, const char __user *buffer,
 void __kmem_cache_free_bulk(struct kmem_cache *, size_t, void **);
 int __kmem_cache_alloc_bulk(struct kmem_cache *, gfp_t, size_t, void **);
 
+static inline int cache_vmstat_idx(struct kmem_cache *s)
+{
+        return (s->flags & SLAB_RECLAIM_ACCOUNT) ?
+                NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE;
+}
+
 #ifdef CONFIG_MEMCG_KMEM
 
 /* List of all root caches. */
@@ -361,6 +367,25 @@ static inline struct kmem_cache *virt_to_cache(const void *obj)
         return page->slab_cache;
 }
 
+static __always_inline int charge_slab_page(struct page *page,
+                                            gfp_t gfp, int order,
+                                            struct kmem_cache *s)
+{
+        int ret = memcg_charge_slab(page, gfp, order, s);
+
+        if (!ret)
+                mod_lruvec_page_state(page, cache_vmstat_idx(s), 1 << order);
+
+        return ret;
+}
+
+static __always_inline void uncharge_slab_page(struct page *page, int order,
+                                               struct kmem_cache *s)
+{
+        mod_lruvec_page_state(page, cache_vmstat_idx(s), -(1 << order));
+        memcg_uncharge_slab(page, order, s);
+}
+
 static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
 {
         struct kmem_cache *cachep;
diff --git a/mm/slub.c b/mm/slub.c
index 845aeaa6c2d4..c9541a480627 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1488,7 +1488,7 @@ static inline struct page *alloc_slab_page(struct kmem_cache *s,
         else
                 page = __alloc_pages_node(node, flags, order);
 
-        if (page && memcg_charge_slab(page, flags, order, s)) {
+        if (page && charge_slab_page(page, flags, order, s)) {
                 __free_pages(page, order);
                 page = NULL;
         }
@@ -1681,11 +1681,6 @@ out:
         if (!page)
                 return NULL;
 
-        mod_lruvec_page_state(page,
-                (s->flags & SLAB_RECLAIM_ACCOUNT) ?
-                NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
-                1 << oo_order(oo));
-
         inc_slabs_node(s, page_to_nid(page), page->objects);
 
         return page;
@@ -1719,18 +1714,13 @@ static void __free_slab(struct kmem_cache *s, struct page *page)
                         check_object(s, page, p, SLUB_RED_INACTIVE);
         }
 
-        mod_lruvec_page_state(page,
-                (s->flags & SLAB_RECLAIM_ACCOUNT) ?
-                NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
-                -pages);
-
         __ClearPageSlabPfmemalloc(page);
         __ClearPageSlab(page);
 
         page->mapping = NULL;
         if (current->reclaim_state)
                 current->reclaim_state->reclaimed_slab += pages;
-        memcg_uncharge_slab(page, order, s);
+        uncharge_slab_page(page, order, s);
         __free_pages(page, order);
 }