bpf: Memcg-based memory accounting for bpf ringbuffer

Enable the memcg-based memory accounting for the memory used by
the bpf ringbuffer.
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-15-guro@fb.com

kernel/bpf/ringbuf.c

@@ -60,8 +60,8 @@ struct bpf_ringbuf_hdr {
 
 static struct bpf_ringbuf *bpf_ringbuf_area_alloc(size_t data_sz, int numa_node)
 {
-	const gfp_t flags = GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN |
-			    __GFP_ZERO;
+	const gfp_t flags = GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL |
+			    __GFP_NOWARN | __GFP_ZERO;
 	int nr_meta_pages = RINGBUF_PGOFF + RINGBUF_POS_PAGES;
 	int nr_data_pages = data_sz >> PAGE_SHIFT;
 	int nr_pages = nr_meta_pages + nr_data_pages;
@@ -88,10 +88,7 @@ static struct bpf_ringbuf *bpf_ringbuf_area_alloc(size_t data_sz, int numa_node)
 	 * user-space implementations significantly.
 	 */
 	array_size = (nr_meta_pages + 2 * nr_data_pages) * sizeof(*pages);
-	if (array_size > PAGE_SIZE)
-		pages = vmalloc_node(array_size, numa_node);
-	else
-		pages = kmalloc_node(array_size, flags, numa_node);
+	pages = bpf_map_area_alloc(array_size, numa_node);
 	if (!pages)
 		return NULL;
 
@@ -167,7 +164,7 @@ static struct bpf_map *ringbuf_map_alloc(union bpf_attr *attr)
 		return ERR_PTR(-E2BIG);
 #endif
 
-	rb_map = kzalloc(sizeof(*rb_map), GFP_USER);
+	rb_map = kzalloc(sizeof(*rb_map), GFP_USER | __GFP_ACCOUNT);
 	if (!rb_map)
 		return ERR_PTR(-ENOMEM);