From b8a943e2942296aad37a8e7adc43db493413e54b Mon Sep 17 00:00:00 2001 From: David Herrmann Date: Sat, 21 Jan 2017 17:26:13 +0100 Subject: [PATCH] samples/bpf: add lpm-trie benchmark Extend the map_perf_test_{user,kern}.c infrastructure to stress test lpm-trie lookups. We hook into the kprobe on sys_gettid() and measure the latency depending on trie size and lookup count. On my Intel Haswell i7-6400U, a single gettid() syscall with an empty bpf program takes roughly 6.5us on my system. Lookups in empty tries take ~1.8us on first try, ~0.9us on retries. Lookups in tries with 8192 entries take ~7.1us (on the first _and_ any subsequent try). Signed-off-by: David Herrmann Reviewed-by: Daniel Mack Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- samples/bpf/map_perf_test_kern.c | 30 ++++++++++++++++++++++++ samples/bpf/map_perf_test_user.c | 49 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 79 insertions(+) diff --git a/samples/bpf/map_perf_test_kern.c b/samples/bpf/map_perf_test_kern.c index 7ee1574..a91872a 100644 --- a/samples/bpf/map_perf_test_kern.c +++ b/samples/bpf/map_perf_test_kern.c @@ -57,6 +57,14 @@ struct bpf_map_def SEC("maps") percpu_hash_map_alloc = { .map_flags = BPF_F_NO_PREALLOC, }; +struct bpf_map_def SEC("maps") lpm_trie_map_alloc = { + .type = BPF_MAP_TYPE_LPM_TRIE, + .key_size = 8, + .value_size = sizeof(long), + .max_entries = 10000, + .map_flags = BPF_F_NO_PREALLOC, +}; + SEC("kprobe/sys_getuid") int stress_hmap(struct pt_regs *ctx) { @@ -135,5 +143,27 @@ int stress_percpu_lru_hmap_alloc(struct pt_regs *ctx) return 0; } +SEC("kprobe/sys_gettid") +int stress_lpm_trie_map_alloc(struct pt_regs *ctx) +{ + union { + u32 b32[2]; + u8 b8[8]; + } key; + unsigned int i; + + key.b32[0] = 32; + key.b8[4] = 192; + key.b8[5] = 168; + key.b8[6] = 0; + key.b8[7] = 1; + +#pragma clang loop unroll(full) + for (i = 0; i < 32; ++i) + bpf_map_lookup_elem(&lpm_trie_map_alloc, &key); + + return 0; +} + char _license[] SEC("license") = "GPL"; u32 _version SEC("version") = LINUX_VERSION_CODE; diff --git a/samples/bpf/map_perf_test_user.c b/samples/bpf/map_perf_test_user.c index 9505b4d..680260a 100644 --- a/samples/bpf/map_perf_test_user.c +++ b/samples/bpf/map_perf_test_user.c @@ -37,6 +37,7 @@ static __u64 time_get_ns(void) #define PERCPU_HASH_KMALLOC (1 << 3) #define LRU_HASH_PREALLOC (1 << 4) #define PERCPU_LRU_HASH_PREALLOC (1 << 5) +#define LPM_KMALLOC (1 << 6) static int test_flags = ~0; @@ -112,6 +113,18 @@ static void test_percpu_hash_kmalloc(int cpu) cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time)); } +static void test_lpm_kmalloc(int cpu) +{ + __u64 start_time; + int i; + + start_time = time_get_ns(); + for (i = 0; i < MAX_CNT; i++) + syscall(__NR_gettid); + printf("%d:lpm_perf kmalloc %lld events per sec\n", + cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time)); +} + static void loop(int cpu) { cpu_set_t cpuset; @@ -137,6 +150,9 @@ static void loop(int cpu) if (test_flags & PERCPU_LRU_HASH_PREALLOC) test_percpu_lru_hash_prealloc(cpu); + + if (test_flags & LPM_KMALLOC) + test_lpm_kmalloc(cpu); } static void run_perf_test(int tasks) @@ -162,6 +178,37 @@ static void run_perf_test(int tasks) } } +static void fill_lpm_trie(void) +{ + struct bpf_lpm_trie_key *key; + unsigned long value = 0; + unsigned int i; + int r; + + key = alloca(sizeof(*key) + 4); + key->prefixlen = 32; + + for (i = 0; i < 512; ++i) { + key->prefixlen = rand() % 33; + key->data[0] = rand() & 0xff; + key->data[1] = rand() & 0xff; + key->data[2] = rand() & 0xff; + key->data[3] = rand() & 0xff; + r = bpf_map_update_elem(map_fd[6], key, &value, 0); + assert(!r); + } + + key->prefixlen = 32; + key->data[0] = 192; + key->data[1] = 168; + key->data[2] = 0; + key->data[3] = 1; + value = 128; + + r = bpf_map_update_elem(map_fd[6], key, &value, 0); + assert(!r); +} + int main(int argc, char **argv) { struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY}; @@ -182,6 +229,8 @@ int main(int argc, char **argv) return 1; } + fill_lpm_trie(); + run_perf_test(num_cpu); return 0; -- 2.7.4