bpf: offload map memory usage

A new helper is introduced to calculate offload map memory usage. But
currently the memory dynamically allocated in netdev dev_ops, like
nsim_map_update_elem, is not counted. Let's just put it aside now.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-18-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 9059520..6792a79 100644 (file)
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -2624,6 +2624,7 @@ static inline bool bpf_map_is_offloaded(struct bpf_map *map)
 
 struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr);
 void bpf_map_offload_map_free(struct bpf_map *map);
+u64 bpf_map_offload_map_mem_usage(const struct bpf_map *map);
 int bpf_prog_test_run_syscall(struct bpf_prog *prog,
                              const union bpf_attr *kattr,
                              union bpf_attr __user *uattr);
@@ -2695,6 +2696,11 @@ static inline void bpf_map_offload_map_free(struct bpf_map *map)
 {
 }
 
+static inline u64 bpf_map_offload_map_mem_usage(const struct bpf_map *map)
+{
+       return 0;
+}
+
 static inline int bpf_prog_test_run_syscall(struct bpf_prog *prog,
                                            const union bpf_attr *kattr,
                                            union bpf_attr __user *uattr)

diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
index 0c85e06..d9c9f45 100644 (file)
--- a/kernel/bpf/offload.c
+++ b/kernel/bpf/offload.c
@@ -563,6 +563,12 @@ void bpf_map_offload_map_free(struct bpf_map *map)
        bpf_map_area_free(offmap);
 }
 
+u64 bpf_map_offload_map_mem_usage(const struct bpf_map *map)
+{
+       /* The memory dynamically allocated in netdev dev_ops is not counted */
+       return sizeof(struct bpf_offloaded_map);
+}
+
 int bpf_map_offload_lookup_elem(struct bpf_map *map, void *key, void *value)
 {
        struct bpf_offloaded_map *offmap = map_to_offmap(map);

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 7c96e68..053409d 100644 (file)
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -105,6 +105,7 @@ const struct bpf_map_ops bpf_map_offload_ops = {
        .map_alloc = bpf_map_offload_map_alloc,
        .map_free = bpf_map_offload_map_free,
        .map_check_btf = map_check_no_btf,
+       .map_mem_usage = bpf_map_offload_map_mem_usage,
 };
 
 static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)