kernel/samples/bpf/map_perf_test_kern.c, branch linux-5.1.y

samples/bpf: Use getppid instead of getpgrp for array map stress

2017-09-21T18:59:16Z

When cross-compiling the bpf sample map_perf_test for aarch64, I find that __NR_getpgrp is undefined. This causes build errors. This syscall is deprecated and requires defining __ARCH_WANT_SYSCALL_DEPRECATED. To avoid having to define that, just use a different syscall (getppid) for the array map stress test. Acked-by: Alexei Starovoitov Signed-off-by: Joel Fernandes Acked-by: Daniel Borkmann Signed-off-by: David S. Miller

bpf: Add lru_hash_lookup performance test

2017-09-01T16:57:38Z

Create a new case to test the LRU lookup performance. At the beginning, the LRU map is fully loaded (i.e. the number of keys is equal to map->max_entries). The lookup is done through key 0 to num_map_entries and then repeats from 0 again. This patch also creates an anonymous struct to properly name the test params in stress_lru_hmap_alloc() in map_perf_test_kern.c. Signed-off-by: Martin KaFai Lau Acked-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller

bpf: Allow numa selection in INNER_LRU_HASH_PREALLOC test of map_perf_test

2017-08-20T04:35:43Z

This patch makes the needed changes to allow each process of the INNER_LRU_HASH_PREALLOC test to provide its numa node id when creating the lru map. Signed-off-by: Martin KaFai Lau Acked-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller

bpf: lru: Add map-in-map LRU example

2017-04-17T17:55:52Z

This patch adds a map-in-map LRU example. If we know only a subset of cores will use the LRU, we can allocate a common LRU list per targeting core and store it into an array-of-hashs. It allows using the common LRU map with map-update performance comparable to the BPF_F_NO_COMMON_LRU map but without wasting memory on the unused cores that we know they will never access the LRU map. BPF_F_NO_COMMON_LRU: > map_perf_test 32 8 10000000 10000000 | awk '{sum += $3}END{print sum}' 9234314 (9.23M/s) map-in-map LRU: > map_perf_test 512 8 1260000 80000000 | awk '{sum += $3}END{print sum}' 9962743 (9.96M/s) Notes that the max_entries for the map-in-map LRU test is 1260000 which is the max_entries for each inner LRU map. 8 processes have been started, so 8 * 1260000 = 10080000 (~10M) which is close to what is used in the BPF_F_NO_COMMON_LRU test. Signed-off-by: Martin KaFai Lau Signed-off-by: David S. Miller

bpf: lru: Refactor LRU map tests in map_perf_test

2017-04-17T17:55:52Z

One more LRU test will be added later in this patch series. In this patch, we first move all existing LRU map tests into a single syscall (connect) first so that the future new LRU test can be added without hunting another syscall. One of the map name is also changed from percpu_lru_hash_map to nocommon_lru_hash_map to avoid the confusion with percpu_hash_map. Signed-off-by: Martin KaFai Lau Acked-by: Alexei Starovoitov Acked-by: Daniel Borkmann Signed-off-by: David S. Miller

samples/bpf: add map_lookup microbenchmark

2017-03-17T03:44:12Z

$ map_perf_test 128 speed of HASH bpf_map_lookup_elem() in lookups per second w/o JIT w/JIT before 46M 58M after 42M 74M perf report before: 54.23% map_perf_test [kernel.kallsyms] [k] __htab_map_lookup_elem 14.24% map_perf_test [kernel.kallsyms] [k] lookup_elem_raw 8.84% map_perf_test [kernel.kallsyms] [k] htab_map_lookup_elem 5.93% map_perf_test [kernel.kallsyms] [k] bpf_map_lookup_elem 2.30% map_perf_test [kernel.kallsyms] [k] bpf_prog_da4fc6a3f41761a2 1.49% map_perf_test [kernel.kallsyms] [k] kprobe_ftrace_handler after: 60.03% map_perf_test [kernel.kallsyms] [k] __htab_map_lookup_elem 18.07% map_perf_test [kernel.kallsyms] [k] lookup_elem_raw 2.91% map_perf_test [kernel.kallsyms] [k] bpf_prog_da4fc6a3f41761a2 1.94% map_perf_test [kernel.kallsyms] [k] _einittext 1.90% map_perf_test [kernel.kallsyms] [k] __audit_syscall_exit 1.72% map_perf_test [kernel.kallsyms] [k] kprobe_ftrace_handler Notice that bpf_map_lookup_elem() and htab_map_lookup_elem() are trivial functions, yet they take sizeable amount of cpu time. htab_map_gen_lookup() removes bpf_map_lookup_elem() and converts htab_map_lookup_elem() into three BPF insns which causing cpu time for bpf_prog_da4fc6a3f41761a2() slightly increase. $ map_perf_test 256 speed of ARRAY bpf_map_lookup_elem() in lookups per second w/o JIT w/JIT before 97M 174M after 64M 280M before: 37.33% map_perf_test [kernel.kallsyms] [k] array_map_lookup_elem 13.95% map_perf_test [kernel.kallsyms] [k] bpf_map_lookup_elem 6.54% map_perf_test [kernel.kallsyms] [k] bpf_prog_da4fc6a3f41761a2 4.57% map_perf_test [kernel.kallsyms] [k] kprobe_ftrace_handler after: 32.86% map_perf_test [kernel.kallsyms] [k] bpf_prog_da4fc6a3f41761a2 6.54% map_perf_test [kernel.kallsyms] [k] kprobe_ftrace_handler array_map_gen_lookup() removes calls to array_map_lookup_elem() and bpf_map_lookup_elem() and replaces them with 7 bpf insns. The performance without JIT is slower, since executing extra insns in the interpreter is slower than running native C code, but with JIT the performance gains are obvious, since native C->x86 code is replaced with fewer bpf->x86 instructions. Signed-off-by: Alexei Starovoitov Acked-by: Daniel Borkmann Signed-off-by: David S. Miller

samples/bpf: add lpm-trie benchmark

2017-01-23T21:10:38Z

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

bpf: Add tests for the LRU bpf_htab

2016-11-15T16:50:43Z

This patch has some unit tests and a test_lru_dist. The test_lru_dist reads in the numeric keys from a file. The files used here are generated by a modified fio-genzipf tool originated from the fio test suit. The sample data file can be found here: https://github.com/iamkafai/bpf-lru The zipf.* data files have 100k numeric keys and the key is also ranged from 1 to 100k. The test_lru_dist outputs the number of unique keys (nr_unique). F.e. The following means, 61239 of them is unique out of 100k keys. nr_misses means it cannot be found in the LRU map, so nr_misses must be >= nr_unique. test_lru_dist also simulates a perfect LRU map as a comparison: [root@arch-fb-vm1 ~]# ~/devshare/fb-kernel/linux/samples/bpf/test_lru_dist \ /root/zipf.100k.a1_01.out 4000 1 ... test_parallel_lru_dist (map_type:9 map_flags:0x0): task:0 BPF LRU: nr_unique:23093(/100000) nr_misses:31603(/100000) task:0 Perfect LRU: nr_unique:23093(/100000 nr_misses:34328(/100000) .... test_parallel_lru_dist (map_type:9 map_flags:0x2): task:0 BPF LRU: nr_unique:23093(/100000) nr_misses:31710(/100000) task:0 Perfect LRU: nr_unique:23093(/100000 nr_misses:34328(/100000) [root@arch-fb-vm1 ~]# ~/devshare/fb-kernel/linux/samples/bpf/test_lru_dist \ /root/zipf.100k.a0_01.out 40000 1 ... test_parallel_lru_dist (map_type:9 map_flags:0x0): task:0 BPF LRU: nr_unique:61239(/100000) nr_misses:67054(/100000) task:0 Perfect LRU: nr_unique:61239(/100000 nr_misses:66993(/100000) ... test_parallel_lru_dist (map_type:9 map_flags:0x2): task:0 BPF LRU: nr_unique:61239(/100000) nr_misses:67068(/100000) task:0 Perfect LRU: nr_unique:61239(/100000 nr_misses:66993(/100000) LRU map has also been added to map_perf_test: /* Global LRU */ [root@kerneltest003.31.prn1 ~]# for i in 1 4 8; do echo -n "$i cpus: "; \ ./map_perf_test 16 $i | awk '{r += $3}END{print r " updates"}'; done 1 cpus: 2934082 updates 4 cpus: 7391434 updates 8 cpus: 6500576 updates /* Percpu LRU */ [root@kerneltest003.31.prn1 ~]# for i in 1 4 8; do echo -n "$i cpus: "; \ ./map_perf_test 32 $i | awk '{r += $3}END{print r " updates"}'; done 1 cpus: 2896553 updates 4 cpus: 9766395 updates 8 cpus: 17460553 updates Signed-off-by: Martin KaFai Lau Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller

samples/bpf: add map performance test

2016-03-09T04:22:03Z

performance tests for hash map and per-cpu hash map with and without pre-allocation Signed-off-by: Alexei Starovoitov Signed-off-by: David S. Miller