From 835f1fca951303930b2c74c5b0abe3c03a3aeadf Mon Sep 17 00:00:00 2001 From: Yafang Shao Date: Sun, 5 Mar 2023 12:46:06 +0000 Subject: bpf: cpumap memory usage A new helper is introduced to calculate cpumap memory usage. The size of cpu_entries can be dynamically changed when we update or delete a cpumap element, but this patch doesn't include the memory size of cpu_entry yet. We can dynamically calculate the memory usage when we alloc or free a cpu_entry, but it will take extra runtime overhead, so let just put it aside currently. Note that the size of different cpu_entry may be different as well. The result as follows, - before 48: cpumap name count_map flags 0x4 key 4B value 4B max_entries 64 memlock 4096B - after 48: cpumap name count_map flags 0x4 key 4B value 4B max_entries 64 memlock 832B Signed-off-by: Yafang Shao Link: https://lore.kernel.org/r/20230305124615.12358-10-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov --- kernel/bpf/cpumap.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'kernel/bpf/cpumap.c') diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c index d2110c1f6fa6..871809e71b4e 100644 --- a/kernel/bpf/cpumap.c +++ b/kernel/bpf/cpumap.c @@ -673,6 +673,15 @@ static int cpu_map_redirect(struct bpf_map *map, u64 index, u64 flags) __cpu_map_lookup_elem); } +static u64 cpu_map_mem_usage(const struct bpf_map *map) +{ + u64 usage = sizeof(struct bpf_cpu_map); + + /* Currently the dynamically allocated elements are not counted */ + usage += (u64)map->max_entries * sizeof(struct bpf_cpu_map_entry *); + return usage; +} + BTF_ID_LIST_SINGLE(cpu_map_btf_ids, struct, bpf_cpu_map) const struct bpf_map_ops cpu_map_ops = { .map_meta_equal = bpf_map_meta_equal, @@ -683,6 +692,7 @@ const struct bpf_map_ops cpu_map_ops = { .map_lookup_elem = cpu_map_lookup_elem, .map_get_next_key = cpu_map_get_next_key, .map_check_btf = map_check_no_btf, + .map_mem_usage = cpu_map_mem_usage, .map_btf_id = &cpu_map_btf_ids[0], .map_redirect = cpu_map_redirect, }; -- cgit v1.2.3-58-ga151