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authorStanislav Fomichev <sdf@google.com>2021-07-27 15:23:35 -0700
committerAndrii Nakryiko <andrii@kernel.org>2021-07-27 15:59:29 -0700
commit33b57e0cc78eb82f2921eb4c6d1c8fcaa733823b (patch)
tree353b54e322ce3e6207a184d048df4e2b14c82f0e /tools
parent043c5bb3c4f43670ab4fea0b847373ab42d25f3e (diff)
downloadlinux-33b57e0cc78eb82f2921eb4c6d1c8fcaa733823b.tar.bz2
bpf: Increase supported cgroup storage value size
Current max cgroup storage value size is 4k (PAGE_SIZE). The other local storages accept up to 64k (BPF_LOCAL_STORAGE_MAX_VALUE_SIZE). Let's align max cgroup value size with the other storages. For percpu, the max is 32k (PCPU_MIN_UNIT_SIZE) because percpu allocator is not happy about larger values. netcnt test is extended to exercise those maximum values (non-percpu max size is close to, but not real max). v4: * remove inner union (Andrii Nakryiko) * keep net_cnt on the stack (Andrii Nakryiko) v3: * refine SIZEOF_BPF_LOCAL_STORAGE_ELEM comment (Yonghong Song) * anonymous struct in percpu_net_cnt & net_cnt (Yonghong Song) * reorder free (Yonghong Song) v2: * cap max_value_size instead of BUILD_BUG_ON (Martin KaFai Lau) Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20210727222335.4029096-1-sdf@google.com
Diffstat (limited to 'tools')
-rw-r--r--tools/testing/selftests/bpf/netcnt_common.h38
-rw-r--r--tools/testing/selftests/bpf/progs/netcnt_prog.c8
-rw-r--r--tools/testing/selftests/bpf/test_netcnt.c4
3 files changed, 35 insertions, 15 deletions
diff --git a/tools/testing/selftests/bpf/netcnt_common.h b/tools/testing/selftests/bpf/netcnt_common.h
index 81084c1c2c23..0ab1c88041cd 100644
--- a/tools/testing/selftests/bpf/netcnt_common.h
+++ b/tools/testing/selftests/bpf/netcnt_common.h
@@ -6,19 +6,39 @@
#define MAX_PERCPU_PACKETS 32
-struct percpu_net_cnt {
- __u64 packets;
- __u64 bytes;
+/* sizeof(struct bpf_local_storage_elem):
+ *
+ * It really is about 128 bytes on x86_64, but allocate more to account for
+ * possible layout changes, different architectures, etc.
+ * The kernel will wrap up to PAGE_SIZE internally anyway.
+ */
+#define SIZEOF_BPF_LOCAL_STORAGE_ELEM 256
- __u64 prev_ts;
+/* Try to estimate kernel's BPF_LOCAL_STORAGE_MAX_VALUE_SIZE: */
+#define BPF_LOCAL_STORAGE_MAX_VALUE_SIZE (0xFFFF - \
+ SIZEOF_BPF_LOCAL_STORAGE_ELEM)
- __u64 prev_packets;
- __u64 prev_bytes;
+#define PCPU_MIN_UNIT_SIZE 32768
+
+union percpu_net_cnt {
+ struct {
+ __u64 packets;
+ __u64 bytes;
+
+ __u64 prev_ts;
+
+ __u64 prev_packets;
+ __u64 prev_bytes;
+ };
+ __u8 data[PCPU_MIN_UNIT_SIZE];
};
-struct net_cnt {
- __u64 packets;
- __u64 bytes;
+union net_cnt {
+ struct {
+ __u64 packets;
+ __u64 bytes;
+ };
+ __u8 data[BPF_LOCAL_STORAGE_MAX_VALUE_SIZE];
};
#endif
diff --git a/tools/testing/selftests/bpf/progs/netcnt_prog.c b/tools/testing/selftests/bpf/progs/netcnt_prog.c
index d071adf178bd..43649bce4c54 100644
--- a/tools/testing/selftests/bpf/progs/netcnt_prog.c
+++ b/tools/testing/selftests/bpf/progs/netcnt_prog.c
@@ -13,21 +13,21 @@
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE);
__type(key, struct bpf_cgroup_storage_key);
- __type(value, struct percpu_net_cnt);
+ __type(value, union percpu_net_cnt);
} percpu_netcnt SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_CGROUP_STORAGE);
__type(key, struct bpf_cgroup_storage_key);
- __type(value, struct net_cnt);
+ __type(value, union net_cnt);
} netcnt SEC(".maps");
SEC("cgroup/skb")
int bpf_nextcnt(struct __sk_buff *skb)
{
- struct percpu_net_cnt *percpu_cnt;
+ union percpu_net_cnt *percpu_cnt;
char fmt[] = "%d %llu %llu\n";
- struct net_cnt *cnt;
+ union net_cnt *cnt;
__u64 ts, dt;
int ret;
diff --git a/tools/testing/selftests/bpf/test_netcnt.c b/tools/testing/selftests/bpf/test_netcnt.c
index a7b9a69f4fd5..4990a99e7381 100644
--- a/tools/testing/selftests/bpf/test_netcnt.c
+++ b/tools/testing/selftests/bpf/test_netcnt.c
@@ -33,14 +33,14 @@ static int bpf_find_map(const char *test, struct bpf_object *obj,
int main(int argc, char **argv)
{
- struct percpu_net_cnt *percpu_netcnt;
+ union percpu_net_cnt *percpu_netcnt;
struct bpf_cgroup_storage_key key;
int map_fd, percpu_map_fd;
int error = EXIT_FAILURE;
- struct net_cnt netcnt;
struct bpf_object *obj;
int prog_fd, cgroup_fd;
unsigned long packets;
+ union net_cnt netcnt;
unsigned long bytes;
int cpu, nproc;
__u32 prog_cnt;