Subject: [PATCH bpf-next v9 29/34] bpf: eliminate rlimit-based memory accounting for stackmap maps

From: Roman Gushchin <[email-masked]>
Date: Tue, 1 Dec 2020 13:58:55 -0800

Do not use rlimit-based memory accounting for stackmap maps.
It has been replaced with the memcg-based memory accounting.

Signed-off-by: Roman Gushchin <[email-masked]>
Acked-by: Song Liu <[email-masked]>
---
 kernel/bpf/stackmap.c | 16 +++-------------
 1 file changed, 3 insertions(+), 13 deletions(-)

diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
index 06065fa27124..3325add8e629 100644
--- a/kernel/bpf/stackmap.c
+++ b/kernel/bpf/stackmap.c
@@ -90,7 +90,6 @@ static struct bpf_map *stack_map_alloc(union bpf_attr *attr)
 {
 	u32 value_size = attr->value_size;
 	struct bpf_stack_map *smap;
-	struct bpf_map_memory mem;
 	u64 cost, n_buckets;
 	int err;
 
@@ -119,15 +118,9 @@ static struct bpf_map *stack_map_alloc(union bpf_attr *attr)
 
 	cost = n_buckets * sizeof(struct stack_map_bucket *) + sizeof(*smap);
 	cost += n_buckets * (value_size + sizeof(struct stack_map_bucket));
-	err = bpf_map_charge_init(&mem, cost);
-	if (err)
-		return ERR_PTR(err);
-
 	smap = bpf_map_area_alloc(cost, bpf_map_attr_numa_node(attr));
-	if (!smap) {
-		bpf_map_charge_finish(&mem);
+	if (!smap)
 		return ERR_PTR(-ENOMEM);
-	}
 
 	bpf_map_init_from_attr(&smap->map, attr);
 	smap->map.value_size = value_size;
@@ -135,20 +128,17 @@ static struct bpf_map *stack_map_alloc(union bpf_attr *attr)
 
 	err = get_callchain_buffers(sysctl_perf_event_max_stack);
 	if (err)
-		goto free_charge;
+		goto free_smap;
 
 	err = prealloc_elems_and_freelist(smap);
 	if (err)
 		goto put_buffers;
 
-	bpf_map_charge_move(&smap->map.memory, &mem);
-
 	return &smap->map;
 
 put_buffers:
 	put_callchain_buffers();
-free_charge:
-	bpf_map_charge_finish(&mem);
+free_smap:
 	bpf_map_area_free(smap);
 	return ERR_PTR(err);
 }
-- 
2.26.2