Commit 90a5527d authored by Yafang Shao's avatar Yafang Shao Committed by Alexei Starovoitov
Browse files

bpf: add new map ops ->map_mem_usage 



Add a new map ops ->map_mem_usage to print the memory usage of a
bpf map.

This is a preparation for the followup change.

Signed-off-by: default avatarYafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-2-laoar.shao@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 2d5bcdcd

include/linux/bpf.h

+2 −0
Original line number Diff line number Diff line
@@ -161,6 +161,8 @@ struct bpf_map_ops { 
				     bpf_callback_t callback_fn,

				     void *callback_ctx, u64 flags);



	u64 (*map_mem_usage)(const struct bpf_map *map);



	/* BTF id of struct allocated by map_alloc */

	int *map_btf_id;

kernel/bpf/syscall.c

+7 −8
Original line number Diff line number Diff line
@@ -771,16 +771,15 @@ static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f) 
}



#ifdef CONFIG_PROC_FS

/* Provides an approximation of the map's memory footprint.

 * Used only to provide a backward compatibility and display

 * a reasonable "memlock" info.

 */

static unsigned long bpf_map_memory_footprint(const struct bpf_map *map)

/* Show the memory usage of a bpf map */

static u64 bpf_map_memory_usage(const struct bpf_map *map)

{

	unsigned long size;



	size = round_up(map->key_size + bpf_map_value_size(map), 8);

	if (map->ops->map_mem_usage)

		return map->ops->map_mem_usage(map);



	size = round_up(map->key_size + bpf_map_value_size(map), 8);

	return round_up(map->max_entries * size, PAGE_SIZE);

}
@@ -803,7 +802,7 @@ static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp) 
		   "max_entries:\t%u\n"

		   "map_flags:\t%#x\n"

		   "map_extra:\t%#llx\n"

		   "memlock:\t%lu\n"

		   "memlock:\t%llu\n"

		   "map_id:\t%u\n"

		   "frozen:\t%u\n",

		   map->map_type,
@@ -812,7 +811,7 @@ static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp) 
		   map->max_entries,

		   map->map_flags,

		   (unsigned long long)map->map_extra,

		   bpf_map_memory_footprint(map),

		   bpf_map_memory_usage(map),

		   map->id,

		   READ_ONCE(map->frozen));

	if (type) {