* [PATCH v3 bpf-next 1/4] selftests/bpf: extract parse_num_list into generic testing_helpers.c
2020-05-12 19:24 [PATCH v3 bpf-next 0/4] Add benchmark runner and few benchmarks Andrii Nakryiko
@ 2020-05-12 19:24 ` Andrii Nakryiko
2020-05-13 1:08 ` Yonghong Song
2020-05-12 19:24 ` [PATCH v3 bpf-next 2/4] selftests/bpf: add benchmark runner infrastructure Andrii Nakryiko
` (3 subsequent siblings)
4 siblings, 1 reply; 9+ messages in thread
From: Andrii Nakryiko @ 2020-05-12 19:24 UTC (permalink / raw)
To: bpf, netdev, ast, daniel; +Cc: andrii.nakryiko, kernel-team, Andrii Nakryiko
Add testing_helpers.c, which will contain generic helpers for test runners and
tests needing some common generic functionality, like parsing a set of
numbers.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
tools/testing/selftests/bpf/Makefile | 3 +-
tools/testing/selftests/bpf/test_progs.c | 67 ++-----------------
tools/testing/selftests/bpf/test_progs.h | 1 +
tools/testing/selftests/bpf/testing_helpers.c | 66 ++++++++++++++++++
tools/testing/selftests/bpf/testing_helpers.h | 5 ++
5 files changed, 78 insertions(+), 64 deletions(-)
create mode 100644 tools/testing/selftests/bpf/testing_helpers.c
create mode 100644 tools/testing/selftests/bpf/testing_helpers.h
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 8f25966b500b..52556712aad4 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -354,7 +354,8 @@ endef
TRUNNER_TESTS_DIR := prog_tests
TRUNNER_BPF_PROGS_DIR := progs
TRUNNER_EXTRA_SOURCES := test_progs.c cgroup_helpers.c trace_helpers.c \
- network_helpers.c flow_dissector_load.h
+ network_helpers.c testing_helpers.c \
+ flow_dissector_load.h
TRUNNER_EXTRA_FILES := $(OUTPUT)/urandom_read \
$(wildcard progs/btf_dump_test_case_*.c)
TRUNNER_BPF_BUILD_RULE := CLANG_BPF_BUILD_RULE
diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index 0f411fdc4f6d..54fa5fa688ce 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -438,67 +438,6 @@ static int parse_str_list(const char *s, struct str_set *set)
return -ENOMEM;
}
-int parse_num_list(const char *s, struct test_selector *sel)
-{
- int i, set_len = 0, new_len, num, start = 0, end = -1;
- bool *set = NULL, *tmp, parsing_end = false;
- char *next;
-
- while (s[0]) {
- errno = 0;
- num = strtol(s, &next, 10);
- if (errno)
- return -errno;
-
- if (parsing_end)
- end = num;
- else
- start = num;
-
- if (!parsing_end && *next == '-') {
- s = next + 1;
- parsing_end = true;
- continue;
- } else if (*next == ',') {
- parsing_end = false;
- s = next + 1;
- end = num;
- } else if (*next == '\0') {
- parsing_end = false;
- s = next;
- end = num;
- } else {
- return -EINVAL;
- }
-
- if (start > end)
- return -EINVAL;
-
- if (end + 1 > set_len) {
- new_len = end + 1;
- tmp = realloc(set, new_len);
- if (!tmp) {
- free(set);
- return -ENOMEM;
- }
- for (i = set_len; i < start; i++)
- tmp[i] = false;
- set = tmp;
- set_len = new_len;
- }
- for (i = start; i <= end; i++)
- set[i] = true;
- }
-
- if (!set)
- return -EINVAL;
-
- sel->num_set = set;
- sel->num_set_len = set_len;
-
- return 0;
-}
-
extern int extra_prog_load_log_flags;
static error_t parse_arg(int key, char *arg, struct argp_state *state)
@@ -512,13 +451,15 @@ static error_t parse_arg(int key, char *arg, struct argp_state *state)
if (subtest_str) {
*subtest_str = '\0';
if (parse_num_list(subtest_str + 1,
- &env->subtest_selector)) {
+ &env->subtest_selector.num_set,
+ &env->subtest_selector.num_set_len)) {
fprintf(stderr,
"Failed to parse subtest numbers.\n");
return -EINVAL;
}
}
- if (parse_num_list(arg, &env->test_selector)) {
+ if (parse_num_list(arg, &env->test_selector.num_set,
+ &env->test_selector.num_set_len)) {
fprintf(stderr, "Failed to parse test numbers.\n");
return -EINVAL;
}
diff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h
index 83287c76332b..f4503c926aca 100644
--- a/tools/testing/selftests/bpf/test_progs.h
+++ b/tools/testing/selftests/bpf/test_progs.h
@@ -37,6 +37,7 @@ typedef __u16 __sum16;
#include "bpf_util.h"
#include <bpf/bpf_endian.h>
#include "trace_helpers.h"
+#include "testing_helpers.h"
#include "flow_dissector_load.h"
enum verbosity {
diff --git a/tools/testing/selftests/bpf/testing_helpers.c b/tools/testing/selftests/bpf/testing_helpers.c
new file mode 100644
index 000000000000..0af6337a8962
--- /dev/null
+++ b/tools/testing/selftests/bpf/testing_helpers.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+/* Copyright (C) 2020 Facebook, Inc. */
+#include <stdlib.h>
+#include <errno.h>
+#include "testing_helpers.h"
+
+int parse_num_list(const char *s, bool **num_set, int *num_set_len)
+{
+ int i, set_len = 0, new_len, num, start = 0, end = -1;
+ bool *set = NULL, *tmp, parsing_end = false;
+ char *next;
+
+ while (s[0]) {
+ errno = 0;
+ num = strtol(s, &next, 10);
+ if (errno)
+ return -errno;
+
+ if (parsing_end)
+ end = num;
+ else
+ start = num;
+
+ if (!parsing_end && *next == '-') {
+ s = next + 1;
+ parsing_end = true;
+ continue;
+ } else if (*next == ',') {
+ parsing_end = false;
+ s = next + 1;
+ end = num;
+ } else if (*next == '\0') {
+ parsing_end = false;
+ s = next;
+ end = num;
+ } else {
+ return -EINVAL;
+ }
+
+ if (start > end)
+ return -EINVAL;
+
+ if (end + 1 > set_len) {
+ new_len = end + 1;
+ tmp = realloc(set, new_len);
+ if (!tmp) {
+ free(set);
+ return -ENOMEM;
+ }
+ for (i = set_len; i < start; i++)
+ tmp[i] = false;
+ set = tmp;
+ set_len = new_len;
+ }
+ for (i = start; i <= end; i++)
+ set[i] = true;
+ }
+
+ if (!set)
+ return -EINVAL;
+
+ *num_set = set;
+ *num_set_len = set_len;
+
+ return 0;
+}
diff --git a/tools/testing/selftests/bpf/testing_helpers.h b/tools/testing/selftests/bpf/testing_helpers.h
new file mode 100644
index 000000000000..923b51762759
--- /dev/null
+++ b/tools/testing/selftests/bpf/testing_helpers.h
@@ -0,0 +1,5 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+/* Copyright (C) 2020 Facebook, Inc. */
+#include <stdbool.h>
+
+int parse_num_list(const char *s, bool **set, int *set_len);
--
2.24.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PATCH v3 bpf-next 2/4] selftests/bpf: add benchmark runner infrastructure
2020-05-12 19:24 [PATCH v3 bpf-next 0/4] Add benchmark runner and few benchmarks Andrii Nakryiko
2020-05-12 19:24 ` [PATCH v3 bpf-next 1/4] selftests/bpf: extract parse_num_list into generic testing_helpers.c Andrii Nakryiko
@ 2020-05-12 19:24 ` Andrii Nakryiko
2020-05-13 1:09 ` Yonghong Song
2020-05-12 19:24 ` [PATCH v3 bpf-next 3/4] selftest/bpf: fmod_ret prog and implement test_overhead as part of bench Andrii Nakryiko
` (2 subsequent siblings)
4 siblings, 1 reply; 9+ messages in thread
From: Andrii Nakryiko @ 2020-05-12 19:24 UTC (permalink / raw)
To: bpf, netdev, ast, daniel; +Cc: andrii.nakryiko, kernel-team, Andrii Nakryiko
While working on BPF ringbuf implementation, testing, and benchmarking, I've
developed a pretty generic and modular benchmark runner, which seems to be
generically useful, as I've already used it for one more purpose (testing
fastest way to trigger BPF program, to minimize overhead of in-kernel code).
This patch adds generic part of benchmark runner and sets up Makefile for
extending it with more sets of benchmarks.
Benchmarker itself operates by spinning up specified number of producer and
consumer threads, setting up interval timer sending SIGALARM signal to
application once a second. Every second, current snapshot with hits/drops
counters are collected and stored in an array. Drops are useful for
producer/consumer benchmarks in which producer might overwhelm consumers.
Once test finishes after given amount of warm-up and testing seconds, mean and
stddev are calculated (ignoring warm-up results) and is printed out to stdout.
This setup seems to give consistent and accurate results.
To validate behavior, I added two atomic counting tests: global and local.
For global one, all the producer threads are atomically incrementing same
counter as fast as possible. This, of course, leads to huge drop of
performance once there is more than one producer thread due to CPUs fighting
for the same memory location.
Local counting, on the other hand, maintains one counter per each producer
thread, incremented independently. Once per second, all counters are read and
added together to form final "counting throughput" measurement. As expected,
such setup demonstrates linear scalability with number of producers (as long
as there are enough physical CPU cores, of course). See example output below.
Also, this setup can nicely demonstrate disastrous effects of false sharing,
if care is not taken to take those per-producer counters apart into
independent cache lines.
Demo output shows global counter first with 1 producer, then with 4. Both
total and per-producer performance significantly drop. The last run is local
counter with 4 producers, demonstrating near-perfect scalability.
$ ./bench -a -w1 -d2 -p1 count-global
Setting up benchmark 'count-global'...
Benchmark 'count-global' started.
Iter 0 ( 24.822us): hits 148.179M/s (148.179M/prod), drops 0.000M/s
Iter 1 ( 37.939us): hits 149.308M/s (149.308M/prod), drops 0.000M/s
Iter 2 (-10.774us): hits 150.717M/s (150.717M/prod), drops 0.000M/s
Iter 3 ( 3.807us): hits 151.435M/s (151.435M/prod), drops 0.000M/s
Summary: hits 150.488 ± 1.079M/s (150.488M/prod), drops 0.000 ± 0.000M/s
$ ./bench -a -w1 -d2 -p4 count-global
Setting up benchmark 'count-global'...
Benchmark 'count-global' started.
Iter 0 ( 60.659us): hits 53.910M/s ( 13.477M/prod), drops 0.000M/s
Iter 1 (-17.658us): hits 53.722M/s ( 13.431M/prod), drops 0.000M/s
Iter 2 ( 5.865us): hits 53.495M/s ( 13.374M/prod), drops 0.000M/s
Iter 3 ( 0.104us): hits 53.606M/s ( 13.402M/prod), drops 0.000M/s
Summary: hits 53.608 ± 0.113M/s ( 13.402M/prod), drops 0.000 ± 0.000M/s
$ ./bench -a -w1 -d2 -p4 count-local
Setting up benchmark 'count-local'...
Benchmark 'count-local' started.
Iter 0 ( 23.388us): hits 640.450M/s (160.113M/prod), drops 0.000M/s
Iter 1 ( 2.291us): hits 605.661M/s (151.415M/prod), drops 0.000M/s
Iter 2 ( -6.415us): hits 607.092M/s (151.773M/prod), drops 0.000M/s
Iter 3 ( -1.361us): hits 601.796M/s (150.449M/prod), drops 0.000M/s
Summary: hits 604.849 ± 2.739M/s (151.212M/prod), drops 0.000 ± 0.000M/s
Benchmark runner supports setting thread affinity for producer and consumer
threads. You can use -a flag for default CPU selection scheme, where first
consumer gets CPU #0, next one gets CPU #1, and so on. Then producer threads
pick up next CPU and increment one-by-one as well. But user can also specify
a set of CPUs independently for producers and consumers with --prod-affinity
1,2-10,15 and --cons-affinity <set-of-cpus>. The latter allows to force
producers and consumers to share same set of CPUs, if necessary.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
tools/testing/selftests/bpf/.gitignore | 1 +
tools/testing/selftests/bpf/Makefile | 13 +-
tools/testing/selftests/bpf/bench.c | 423 ++++++++++++++++++
tools/testing/selftests/bpf/bench.h | 81 ++++
.../selftests/bpf/benchs/bench_count.c | 91 ++++
5 files changed, 608 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/bpf/bench.c
create mode 100644 tools/testing/selftests/bpf/bench.h
create mode 100644 tools/testing/selftests/bpf/benchs/bench_count.c
diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore
index 3ff031972975..1bb204cee853 100644
--- a/tools/testing/selftests/bpf/.gitignore
+++ b/tools/testing/selftests/bpf/.gitignore
@@ -38,3 +38,4 @@ test_cpp
/bpf_gcc
/tools
/runqslower
+/bench
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 52556712aad4..2ad0ef00f45c 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -77,7 +77,7 @@ TEST_PROGS_EXTENDED := with_addr.sh \
# Compile but not part of 'make run_tests'
TEST_GEN_PROGS_EXTENDED = test_sock_addr test_skb_cgroup_id_user \
flow_dissector_load test_flow_dissector test_tcp_check_syncookie_user \
- test_lirc_mode2_user xdping test_cpp runqslower
+ test_lirc_mode2_user xdping test_cpp runqslower bench
TEST_CUSTOM_PROGS = urandom_read
@@ -406,6 +406,17 @@ $(OUTPUT)/test_cpp: test_cpp.cpp $(OUTPUT)/test_core_extern.skel.h $(BPFOBJ)
$(call msg,CXX,,$@)
$(CXX) $(CFLAGS) $^ $(LDLIBS) -o $@
+# Benchmark runner
+$(OUTPUT)/bench_%.o: benchs/bench_%.c bench.h
+ $(call msg,CC,,$@)
+ $(CC) $(CFLAGS) -c $(filter %.c,$^) $(LDLIBS) -o $@
+$(OUTPUT)/bench.o: bench.h testing_helpers.h
+$(OUTPUT)/bench: LDLIBS += -lm
+$(OUTPUT)/bench: $(OUTPUT)/bench.o $(OUTPUT)/testing_helpers.o \
+ $(OUTPUT)/bench_count.o
+ $(call msg,BINARY,,$@)
+ $(CC) $(LDFLAGS) -o $@ $(filter %.a %.o,$^) $(LDLIBS)
+
EXTRA_CLEAN := $(TEST_CUSTOM_PROGS) $(SCRATCH_DIR) \
prog_tests/tests.h map_tests/tests.h verifier/tests.h \
feature \
diff --git a/tools/testing/selftests/bpf/bench.c b/tools/testing/selftests/bpf/bench.c
new file mode 100644
index 000000000000..3972da8b19e8
--- /dev/null
+++ b/tools/testing/selftests/bpf/bench.c
@@ -0,0 +1,423 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+#define _GNU_SOURCE
+#include <argp.h>
+#include <linux/compiler.h>
+#include <sys/time.h>
+#include <sched.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <sys/sysinfo.h>
+#include <sys/resource.h>
+#include <signal.h>
+#include "bench.h"
+#include "testing_helpers.h"
+
+struct env env = {
+ .warmup_sec = 1,
+ .duration_sec = 5,
+ .affinity = false,
+ .consumer_cnt = 1,
+ .producer_cnt = 1,
+};
+
+static int libbpf_print_fn(enum libbpf_print_level level,
+ const char *format, va_list args)
+{
+ if (level == LIBBPF_DEBUG && !env.verbose)
+ return 0;
+ return vfprintf(stderr, format, args);
+}
+
+static int bump_memlock_rlimit(void)
+{
+ struct rlimit rlim_new = {
+ .rlim_cur = RLIM_INFINITY,
+ .rlim_max = RLIM_INFINITY,
+ };
+
+ return setrlimit(RLIMIT_MEMLOCK, &rlim_new);
+}
+
+void setup_libbpf()
+{
+ int err;
+
+ libbpf_set_print(libbpf_print_fn);
+
+ err = bump_memlock_rlimit();
+ if (err)
+ fprintf(stderr, "failed to increase RLIMIT_MEMLOCK: %d", err);
+}
+
+void hits_drops_report_progress(int iter, struct bench_res *res, long delta_ns)
+{
+ double hits_per_sec, drops_per_sec;
+ double hits_per_prod;
+
+ hits_per_sec = res->hits / 1000000.0 / (delta_ns / 1000000000.0);
+ hits_per_prod = hits_per_sec / env.producer_cnt;
+ drops_per_sec = res->drops / 1000000.0 / (delta_ns / 1000000000.0);
+
+ printf("Iter %3d (%7.3lfus): ",
+ iter, (delta_ns - 1000000000) / 1000.0);
+
+ printf("hits %8.3lfM/s (%7.3lfM/prod), drops %8.3lfM/s\n",
+ hits_per_sec, hits_per_prod, drops_per_sec);
+}
+
+void hits_drops_report_final(struct bench_res res[], int res_cnt)
+{
+ int i;
+ double hits_mean = 0.0, drops_mean = 0.0;
+ double hits_stddev = 0.0, drops_stddev = 0.0;
+
+ for (i = 0; i < res_cnt; i++) {
+ hits_mean += res[i].hits / 1000000.0 / (0.0 + res_cnt);
+ drops_mean += res[i].drops / 1000000.0 / (0.0 + res_cnt);
+ }
+
+ if (res_cnt > 1) {
+ for (i = 0; i < res_cnt; i++) {
+ hits_stddev += (hits_mean - res[i].hits / 1000000.0) *
+ (hits_mean - res[i].hits / 1000000.0) /
+ (res_cnt - 1.0);
+ drops_stddev += (drops_mean - res[i].drops / 1000000.0) *
+ (drops_mean - res[i].drops / 1000000.0) /
+ (res_cnt - 1.0);
+ }
+ hits_stddev = sqrt(hits_stddev);
+ drops_stddev = sqrt(drops_stddev);
+ }
+ printf("Summary: hits %8.3lf \u00B1 %5.3lfM/s (%7.3lfM/prod), ",
+ hits_mean, hits_stddev, hits_mean / env.producer_cnt);
+ printf("drops %8.3lf \u00B1 %5.3lfM/s\n",
+ drops_mean, drops_stddev);
+}
+
+const char *argp_program_version = "benchmark";
+const char *argp_program_bug_address = "<bpf@vger.kernel.org>";
+const char argp_program_doc[] =
+"benchmark Generic benchmarking framework.\n"
+"\n"
+"This tool runs benchmarks.\n"
+"\n"
+"USAGE: benchmark <bench-name>\n"
+"\n"
+"EXAMPLES:\n"
+" # run 'count-local' benchmark with 1 producer and 1 consumer\n"
+" benchmark count-local\n"
+" # run 'count-local' with 16 producer and 8 consumer thread, pinned to CPUs\n"
+" benchmark -p16 -c8 -a count-local\n";
+
+enum {
+ ARG_PROD_AFFINITY_SET = 1000,
+ ARG_CONS_AFFINITY_SET = 1001,
+};
+
+static const struct argp_option opts[] = {
+ { "list", 'l', NULL, 0, "List available benchmarks"},
+ { "duration", 'd', "SEC", 0, "Duration of benchmark, seconds"},
+ { "warmup", 'w', "SEC", 0, "Warm-up period, seconds"},
+ { "producers", 'p', "NUM", 0, "Number of producer threads"},
+ { "consumers", 'c', "NUM", 0, "Number of consumer threads"},
+ { "verbose", 'v', NULL, 0, "Verbose debug output"},
+ { "affinity", 'a', NULL, 0, "Set consumer/producer thread affinity"},
+ { "prod-affinity", ARG_PROD_AFFINITY_SET, "CPUSET", 0,
+ "Set of CPUs for producer threads; implies --affinity"},
+ { "cons-affinity", ARG_CONS_AFFINITY_SET, "CPUSET", 0,
+ "Set of CPUs for consumer threads; implies --affinity"},
+ {},
+};
+
+static error_t parse_arg(int key, char *arg, struct argp_state *state)
+{
+ static int pos_args;
+
+ switch (key) {
+ case 'v':
+ env.verbose = true;
+ break;
+ case 'l':
+ env.list = true;
+ break;
+ case 'd':
+ env.duration_sec = strtol(arg, NULL, 10);
+ if (env.duration_sec <= 0) {
+ fprintf(stderr, "Invalid duration: %s\n", arg);
+ argp_usage(state);
+ }
+ break;
+ case 'w':
+ env.warmup_sec = strtol(arg, NULL, 10);
+ if (env.warmup_sec <= 0) {
+ fprintf(stderr, "Invalid warm-up duration: %s\n", arg);
+ argp_usage(state);
+ }
+ break;
+ case 'p':
+ env.producer_cnt = strtol(arg, NULL, 10);
+ if (env.producer_cnt <= 0) {
+ fprintf(stderr, "Invalid producer count: %s\n", arg);
+ argp_usage(state);
+ }
+ break;
+ case 'c':
+ env.consumer_cnt = strtol(arg, NULL, 10);
+ if (env.consumer_cnt <= 0) {
+ fprintf(stderr, "Invalid consumer count: %s\n", arg);
+ argp_usage(state);
+ }
+ break;
+ case 'a':
+ env.affinity = true;
+ break;
+ case ARG_PROD_AFFINITY_SET:
+ env.affinity = true;
+ if (parse_num_list(arg, &env.prod_cpus.cpus,
+ &env.prod_cpus.cpus_len)) {
+ fprintf(stderr, "Invalid format of CPU set for producers.");
+ argp_usage(state);
+ }
+ break;
+ case ARG_CONS_AFFINITY_SET:
+ env.affinity = true;
+ if (parse_num_list(arg, &env.cons_cpus.cpus,
+ &env.cons_cpus.cpus_len)) {
+ fprintf(stderr, "Invalid format of CPU set for consumers.");
+ argp_usage(state);
+ }
+ break;
+ case ARGP_KEY_ARG:
+ if (pos_args++) {
+ fprintf(stderr,
+ "Unrecognized positional argument: %s\n", arg);
+ argp_usage(state);
+ }
+ env.bench_name = strdup(arg);
+ break;
+ default:
+ return ARGP_ERR_UNKNOWN;
+ }
+ return 0;
+}
+
+static void parse_cmdline_args(int argc, char **argv)
+{
+ static const struct argp argp = {
+ .options = opts,
+ .parser = parse_arg,
+ .doc = argp_program_doc,
+ };
+ if (argp_parse(&argp, argc, argv, 0, NULL, NULL))
+ exit(1);
+ if (!env.list && !env.bench_name) {
+ argp_help(&argp, stderr, ARGP_HELP_DOC, "bench");
+ exit(1);
+ }
+}
+
+static void collect_measurements(long delta_ns);
+
+static __u64 last_time_ns;
+static void sigalarm_handler(int signo)
+{
+ long new_time_ns = get_time_ns();
+ long delta_ns = new_time_ns - last_time_ns;
+
+ collect_measurements(delta_ns);
+
+ last_time_ns = new_time_ns;
+}
+
+/* set up periodic 1-second timer */
+static void setup_timer()
+{
+ static struct sigaction sigalarm_action = {
+ .sa_handler = sigalarm_handler,
+ };
+ struct itimerval timer_settings = {};
+ int err;
+
+ last_time_ns = get_time_ns();
+ err = sigaction(SIGALRM, &sigalarm_action, NULL);
+ if (err < 0) {
+ fprintf(stderr, "failed to install SIGALARM handler: %d\n", -errno);
+ exit(1);
+ }
+ timer_settings.it_interval.tv_sec = 1;
+ timer_settings.it_value.tv_sec = 1;
+ err = setitimer(ITIMER_REAL, &timer_settings, NULL);
+ if (err < 0) {
+ fprintf(stderr, "failed to arm interval timer: %d\n", -errno);
+ exit(1);
+ }
+}
+
+static void set_thread_affinity(pthread_t thread, int cpu)
+{
+ cpu_set_t cpuset;
+
+ CPU_ZERO(&cpuset);
+ CPU_SET(cpu, &cpuset);
+ if (pthread_setaffinity_np(thread, sizeof(cpuset), &cpuset)) {
+ fprintf(stderr, "setting affinity to CPU #%d failed: %d\n",
+ cpu, errno);
+ exit(1);
+ }
+}
+
+static int next_cpu(struct cpu_set *cpu_set)
+{
+ if (cpu_set->cpus) {
+ int i;
+
+ /* find next available CPU */
+ for (i = cpu_set->next_cpu; i < cpu_set->cpus_len; i++) {
+ if (cpu_set->cpus[i]) {
+ cpu_set->next_cpu = i + 1;
+ return i;
+ }
+ }
+ fprintf(stderr, "Not enough CPUs specified, need CPU #%d or higher.\n", i);
+ exit(1);
+ }
+
+ return cpu_set->next_cpu++;
+}
+
+static struct bench_state {
+ int res_cnt;
+ struct bench_res *results;
+ pthread_t *consumers;
+ pthread_t *producers;
+} state;
+
+const struct bench *bench = NULL;
+
+extern const struct bench bench_count_global;
+extern const struct bench bench_count_local;
+
+static const struct bench *benchs[] = {
+ &bench_count_global,
+ &bench_count_local,
+};
+
+static void setup_benchmark()
+{
+ int i, err;
+
+ if (!env.bench_name) {
+ fprintf(stderr, "benchmark name is not specified\n");
+ exit(1);
+ }
+
+ for (i = 0; i < ARRAY_SIZE(benchs); i++) {
+ if (strcmp(benchs[i]->name, env.bench_name) == 0) {
+ bench = benchs[i];
+ break;
+ }
+ }
+ if (!bench) {
+ fprintf(stderr, "benchmark '%s' not found\n", env.bench_name);
+ exit(1);
+ }
+
+ printf("Setting up benchmark '%s'...\n", bench->name);
+
+ state.producers = calloc(env.producer_cnt, sizeof(*state.producers));
+ state.consumers = calloc(env.consumer_cnt, sizeof(*state.consumers));
+ state.results = calloc(env.duration_sec + env.warmup_sec + 2,
+ sizeof(*state.results));
+ if (!state.producers || !state.consumers || !state.results)
+ exit(1);
+
+ if (bench->validate)
+ bench->validate();
+ if (bench->setup)
+ bench->setup();
+
+ for (i = 0; i < env.consumer_cnt; i++) {
+ err = pthread_create(&state.consumers[i], NULL,
+ bench->consumer_thread, (void *)(long)i);
+ if (err) {
+ fprintf(stderr, "failed to create consumer thread #%d: %d\n",
+ i, -errno);
+ exit(1);
+ }
+ if (env.affinity)
+ set_thread_affinity(state.consumers[i],
+ next_cpu(&env.cons_cpus));
+ }
+
+ /* unless explicit producer CPU list is specified, continue after
+ * last consumer CPU
+ */
+ if (!env.prod_cpus.cpus)
+ env.prod_cpus.next_cpu = env.cons_cpus.next_cpu;
+
+ for (i = 0; i < env.producer_cnt; i++) {
+ err = pthread_create(&state.producers[i], NULL,
+ bench->producer_thread, (void *)(long)i);
+ if (err) {
+ fprintf(stderr, "failed to create producer thread #%d: %d\n",
+ i, -errno);
+ exit(1);
+ }
+ if (env.affinity)
+ set_thread_affinity(state.producers[i],
+ next_cpu(&env.prod_cpus));
+ }
+
+ printf("Benchmark '%s' started.\n", bench->name);
+}
+
+static pthread_mutex_t bench_done_mtx = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t bench_done = PTHREAD_COND_INITIALIZER;
+
+static void collect_measurements(long delta_ns) {
+ int iter = state.res_cnt++;
+ struct bench_res *res = &state.results[iter];
+
+ bench->measure(res);
+
+ if (bench->report_progress)
+ bench->report_progress(iter, res, delta_ns);
+
+ if (iter == env.duration_sec + env.warmup_sec) {
+ pthread_mutex_lock(&bench_done_mtx);
+ pthread_cond_signal(&bench_done);
+ pthread_mutex_unlock(&bench_done_mtx);
+ }
+}
+
+int main(int argc, char **argv)
+{
+ parse_cmdline_args(argc, argv);
+
+ if (env.list) {
+ int i;
+
+ printf("Available benchmarks:\n");
+ for (i = 0; i < ARRAY_SIZE(benchs); i++) {
+ printf("- %s\n", benchs[i]->name);
+ }
+ return 0;
+ }
+
+ setup_benchmark();
+
+ setup_timer();
+
+ pthread_mutex_lock(&bench_done_mtx);
+ pthread_cond_wait(&bench_done, &bench_done_mtx);
+ pthread_mutex_unlock(&bench_done_mtx);
+
+ if (bench->report_final)
+ /* skip first sample */
+ bench->report_final(state.results + env.warmup_sec,
+ state.res_cnt - env.warmup_sec);
+
+ return 0;
+}
+
diff --git a/tools/testing/selftests/bpf/bench.h b/tools/testing/selftests/bpf/bench.h
new file mode 100644
index 000000000000..c1f48a473b02
--- /dev/null
+++ b/tools/testing/selftests/bpf/bench.h
@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#pragma once
+#include <stdlib.h>
+#include <stdbool.h>
+#include <linux/err.h>
+#include <errno.h>
+#include <unistd.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include <math.h>
+#include <time.h>
+#include <sys/syscall.h>
+
+struct cpu_set {
+ bool *cpus;
+ int cpus_len;
+ int next_cpu;
+};
+
+struct env {
+ char *bench_name;
+ int duration_sec;
+ int warmup_sec;
+ bool verbose;
+ bool list;
+ bool affinity;
+ int consumer_cnt;
+ int producer_cnt;
+ struct cpu_set prod_cpus;
+ struct cpu_set cons_cpus;
+};
+
+struct bench_res {
+ long hits;
+ long drops;
+};
+
+struct bench {
+ const char *name;
+ void (*validate)();
+ void (*setup)();
+ void *(*producer_thread)(void *ctx);
+ void *(*consumer_thread)(void *ctx);
+ void (*measure)(struct bench_res* res);
+ void (*report_progress)(int iter, struct bench_res* res, long delta_ns);
+ void (*report_final)(struct bench_res res[], int res_cnt);
+};
+
+struct counter {
+ long value;
+} __attribute__((aligned(128)));
+
+extern struct env env;
+extern const struct bench *bench;
+
+void setup_libbpf();
+void hits_drops_report_progress(int iter, struct bench_res *res, long delta_ns);
+void hits_drops_report_final(struct bench_res res[], int res_cnt);
+
+static inline __u64 get_time_ns() {
+ struct timespec t;
+
+ clock_gettime(CLOCK_MONOTONIC, &t);
+
+ return (u64)t.tv_sec * 1000000000 + t.tv_nsec;
+}
+
+static inline void atomic_inc(long *value)
+{
+ (void)__atomic_add_fetch(value, 1, __ATOMIC_RELAXED);
+}
+
+static inline void atomic_add(long *value, long n)
+{
+ (void)__atomic_add_fetch(value, n, __ATOMIC_RELAXED);
+}
+
+static inline long atomic_swap(long *value, long n)
+{
+ return __atomic_exchange_n(value, n, __ATOMIC_RELAXED);
+}
diff --git a/tools/testing/selftests/bpf/benchs/bench_count.c b/tools/testing/selftests/bpf/benchs/bench_count.c
new file mode 100644
index 000000000000..befba7a82643
--- /dev/null
+++ b/tools/testing/selftests/bpf/benchs/bench_count.c
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+#include "bench.h"
+
+/* COUNT-GLOBAL benchmark */
+
+static struct count_global_ctx {
+ struct counter hits;
+} count_global_ctx;
+
+static void *count_global_producer(void *input)
+{
+ struct count_global_ctx *ctx = &count_global_ctx;
+
+ while (true) {
+ atomic_inc(&ctx->hits.value);
+ }
+ return NULL;
+}
+
+static void *count_global_consumer(void *input)
+{
+ return NULL;
+}
+
+static void count_global_measure(struct bench_res *res)
+{
+ struct count_global_ctx *ctx = &count_global_ctx;
+
+ res->hits = atomic_swap(&ctx->hits.value, 0);
+}
+
+/* COUNT-local benchmark */
+
+static struct count_local_ctx {
+ struct counter *hits;
+} count_local_ctx;
+
+static void count_local_setup()
+{
+ struct count_local_ctx *ctx = &count_local_ctx;
+
+ ctx->hits = calloc(env.consumer_cnt, sizeof(*ctx->hits));
+ if (!ctx->hits)
+ exit(1);
+}
+
+static void *count_local_producer(void *input)
+{
+ struct count_local_ctx *ctx = &count_local_ctx;
+ int idx = (long)input;
+
+ while (true) {
+ atomic_inc(&ctx->hits[idx].value);
+ }
+ return NULL;
+}
+
+static void *count_local_consumer(void *input)
+{
+ return NULL;
+}
+
+static void count_local_measure(struct bench_res *res)
+{
+ struct count_local_ctx *ctx = &count_local_ctx;
+ int i;
+
+ for (i = 0; i < env.producer_cnt; i++) {
+ res->hits += atomic_swap(&ctx->hits[i].value, 0);
+ }
+}
+
+const struct bench bench_count_global = {
+ .name = "count-global",
+ .producer_thread = count_global_producer,
+ .consumer_thread = count_global_consumer,
+ .measure = count_global_measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_count_local = {
+ .name = "count-local",
+ .setup = count_local_setup,
+ .producer_thread = count_local_producer,
+ .consumer_thread = count_local_consumer,
+ .measure = count_local_measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
--
2.24.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH v3 bpf-next 2/4] selftests/bpf: add benchmark runner infrastructure
2020-05-12 19:24 ` [PATCH v3 bpf-next 2/4] selftests/bpf: add benchmark runner infrastructure Andrii Nakryiko
@ 2020-05-13 1:09 ` Yonghong Song
0 siblings, 0 replies; 9+ messages in thread
From: Yonghong Song @ 2020-05-13 1:09 UTC (permalink / raw)
To: Andrii Nakryiko, bpf, netdev, ast, daniel; +Cc: andrii.nakryiko, kernel-team
On 5/12/20 12:24 PM, Andrii Nakryiko wrote:
> While working on BPF ringbuf implementation, testing, and benchmarking, I've
> developed a pretty generic and modular benchmark runner, which seems to be
> generically useful, as I've already used it for one more purpose (testing
> fastest way to trigger BPF program, to minimize overhead of in-kernel code).
>
> This patch adds generic part of benchmark runner and sets up Makefile for
> extending it with more sets of benchmarks.
>
> Benchmarker itself operates by spinning up specified number of producer and
> consumer threads, setting up interval timer sending SIGALARM signal to
> application once a second. Every second, current snapshot with hits/drops
> counters are collected and stored in an array. Drops are useful for
> producer/consumer benchmarks in which producer might overwhelm consumers.
>
> Once test finishes after given amount of warm-up and testing seconds, mean and
> stddev are calculated (ignoring warm-up results) and is printed out to stdout.
> This setup seems to give consistent and accurate results.
>
> To validate behavior, I added two atomic counting tests: global and local.
> For global one, all the producer threads are atomically incrementing same
> counter as fast as possible. This, of course, leads to huge drop of
> performance once there is more than one producer thread due to CPUs fighting
> for the same memory location.
>
> Local counting, on the other hand, maintains one counter per each producer
> thread, incremented independently. Once per second, all counters are read and
> added together to form final "counting throughput" measurement. As expected,
> such setup demonstrates linear scalability with number of producers (as long
> as there are enough physical CPU cores, of course). See example output below.
> Also, this setup can nicely demonstrate disastrous effects of false sharing,
> if care is not taken to take those per-producer counters apart into
> independent cache lines.
>
> Demo output shows global counter first with 1 producer, then with 4. Both
> total and per-producer performance significantly drop. The last run is local
> counter with 4 producers, demonstrating near-perfect scalability.
>
> $ ./bench -a -w1 -d2 -p1 count-global
> Setting up benchmark 'count-global'...
> Benchmark 'count-global' started.
> Iter 0 ( 24.822us): hits 148.179M/s (148.179M/prod), drops 0.000M/s
> Iter 1 ( 37.939us): hits 149.308M/s (149.308M/prod), drops 0.000M/s
> Iter 2 (-10.774us): hits 150.717M/s (150.717M/prod), drops 0.000M/s
> Iter 3 ( 3.807us): hits 151.435M/s (151.435M/prod), drops 0.000M/s
> Summary: hits 150.488 ± 1.079M/s (150.488M/prod), drops 0.000 ± 0.000M/s
>
> $ ./bench -a -w1 -d2 -p4 count-global
> Setting up benchmark 'count-global'...
> Benchmark 'count-global' started.
> Iter 0 ( 60.659us): hits 53.910M/s ( 13.477M/prod), drops 0.000M/s
> Iter 1 (-17.658us): hits 53.722M/s ( 13.431M/prod), drops 0.000M/s
> Iter 2 ( 5.865us): hits 53.495M/s ( 13.374M/prod), drops 0.000M/s
> Iter 3 ( 0.104us): hits 53.606M/s ( 13.402M/prod), drops 0.000M/s
> Summary: hits 53.608 ± 0.113M/s ( 13.402M/prod), drops 0.000 ± 0.000M/s
>
> $ ./bench -a -w1 -d2 -p4 count-local
> Setting up benchmark 'count-local'...
> Benchmark 'count-local' started.
> Iter 0 ( 23.388us): hits 640.450M/s (160.113M/prod), drops 0.000M/s
> Iter 1 ( 2.291us): hits 605.661M/s (151.415M/prod), drops 0.000M/s
> Iter 2 ( -6.415us): hits 607.092M/s (151.773M/prod), drops 0.000M/s
> Iter 3 ( -1.361us): hits 601.796M/s (150.449M/prod), drops 0.000M/s
> Summary: hits 604.849 ± 2.739M/s (151.212M/prod), drops 0.000 ± 0.000M/s
>
> Benchmark runner supports setting thread affinity for producer and consumer
> threads. You can use -a flag for default CPU selection scheme, where first
> consumer gets CPU #0, next one gets CPU #1, and so on. Then producer threads
> pick up next CPU and increment one-by-one as well. But user can also specify
> a set of CPUs independently for producers and consumers with --prod-affinity
> 1,2-10,15 and --cons-affinity <set-of-cpus>. The latter allows to force
> producers and consumers to share same set of CPUs, if necessary.
>
> Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v3 bpf-next 3/4] selftest/bpf: fmod_ret prog and implement test_overhead as part of bench
2020-05-12 19:24 [PATCH v3 bpf-next 0/4] Add benchmark runner and few benchmarks Andrii Nakryiko
2020-05-12 19:24 ` [PATCH v3 bpf-next 1/4] selftests/bpf: extract parse_num_list into generic testing_helpers.c Andrii Nakryiko
2020-05-12 19:24 ` [PATCH v3 bpf-next 2/4] selftests/bpf: add benchmark runner infrastructure Andrii Nakryiko
@ 2020-05-12 19:24 ` Andrii Nakryiko
2020-05-13 1:10 ` Yonghong Song
2020-05-12 19:24 ` [PATCH v3 bpf-next 4/4] selftest/bpf: add BPF triggering benchmark Andrii Nakryiko
2020-05-13 19:23 ` [PATCH v3 bpf-next 0/4] Add benchmark runner and few benchmarks Alexei Starovoitov
4 siblings, 1 reply; 9+ messages in thread
From: Andrii Nakryiko @ 2020-05-12 19:24 UTC (permalink / raw)
To: bpf, netdev, ast, daniel
Cc: andrii.nakryiko, kernel-team, Andrii Nakryiko, John Fastabend
Add fmod_ret BPF program to existing test_overhead selftest. Also re-implement
user-space benchmarking part into benchmark runner to compare results. Results
with ./bench are consistently somewhat lower than test_overhead's, but relative
performance of various types of BPF programs stay consisten (e.g., kretprobe is
noticeably slower). This slowdown seems to be coming from the fact that
test_overhead is single-threaded, while benchmark always spins off at least
one thread for producer. This has been confirmed by hacking multi-threaded
test_overhead variant and also single-threaded bench variant. Resutls are
below. run_bench_rename.sh script from benchs/ subdirectory was used to
produce results for ./bench.
Single-threaded implementations
===============================
/* bench: single-threaded, atomics */
base : 4.622 ± 0.049M/s
kprobe : 3.673 ± 0.052M/s
kretprobe : 2.625 ± 0.052M/s
rawtp : 4.369 ± 0.089M/s
fentry : 4.201 ± 0.558M/s
fexit : 4.309 ± 0.148M/s
fmodret : 4.314 ± 0.203M/s
/* selftest: single-threaded, no atomics */
task_rename base 4555K events per sec
task_rename kprobe 3643K events per sec
task_rename kretprobe 2506K events per sec
task_rename raw_tp 4303K events per sec
task_rename fentry 4307K events per sec
task_rename fexit 4010K events per sec
task_rename fmod_ret 3984K events per sec
Multi-threaded implementations
==============================
/* bench: multi-threaded w/ atomics */
base : 3.910 ± 0.023M/s
kprobe : 3.048 ± 0.037M/s
kretprobe : 2.300 ± 0.015M/s
rawtp : 3.687 ± 0.034M/s
fentry : 3.740 ± 0.087M/s
fexit : 3.510 ± 0.009M/s
fmodret : 3.485 ± 0.050M/s
/* selftest: multi-threaded w/ atomics */
task_rename base 3872K events per sec
task_rename kprobe 3068K events per sec
task_rename kretprobe 2350K events per sec
task_rename raw_tp 3731K events per sec
task_rename fentry 3639K events per sec
task_rename fexit 3558K events per sec
task_rename fmod_ret 3511K events per sec
/* selftest: multi-threaded, no atomics */
task_rename base 3945K events per sec
task_rename kprobe 3298K events per sec
task_rename kretprobe 2451K events per sec
task_rename raw_tp 3718K events per sec
task_rename fentry 3782K events per sec
task_rename fexit 3543K events per sec
task_rename fmod_ret 3526K events per sec
Note that the fact that ./bench benchmark always uses atomic increments for
counting, while test_overhead doesn't, doesn't influence test results all that
much.
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
tools/testing/selftests/bpf/Makefile | 4 +-
tools/testing/selftests/bpf/bench.c | 14 ++
.../selftests/bpf/benchs/bench_rename.c | 195 ++++++++++++++++++
.../selftests/bpf/benchs/run_bench_rename.sh | 9 +
.../selftests/bpf/prog_tests/test_overhead.c | 14 +-
.../selftests/bpf/progs/test_overhead.c | 6 +
6 files changed, 240 insertions(+), 2 deletions(-)
create mode 100644 tools/testing/selftests/bpf/benchs/bench_rename.c
create mode 100755 tools/testing/selftests/bpf/benchs/run_bench_rename.sh
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 2ad0ef00f45c..3c43d4eceba8 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -410,10 +410,12 @@ $(OUTPUT)/test_cpp: test_cpp.cpp $(OUTPUT)/test_core_extern.skel.h $(BPFOBJ)
$(OUTPUT)/bench_%.o: benchs/bench_%.c bench.h
$(call msg,CC,,$@)
$(CC) $(CFLAGS) -c $(filter %.c,$^) $(LDLIBS) -o $@
+$(OUTPUT)/bench_rename.o: $(OUTPUT)/test_overhead.skel.h
$(OUTPUT)/bench.o: bench.h testing_helpers.h
$(OUTPUT)/bench: LDLIBS += -lm
$(OUTPUT)/bench: $(OUTPUT)/bench.o $(OUTPUT)/testing_helpers.o \
- $(OUTPUT)/bench_count.o
+ $(OUTPUT)/bench_count.o \
+ $(OUTPUT)/bench_rename.o
$(call msg,BINARY,,$@)
$(CC) $(LDFLAGS) -o $@ $(filter %.a %.o,$^) $(LDLIBS)
diff --git a/tools/testing/selftests/bpf/bench.c b/tools/testing/selftests/bpf/bench.c
index 3972da8b19e8..c9e8b7dbaf66 100644
--- a/tools/testing/selftests/bpf/bench.c
+++ b/tools/testing/selftests/bpf/bench.c
@@ -297,10 +297,24 @@ const struct bench *bench = NULL;
extern const struct bench bench_count_global;
extern const struct bench bench_count_local;
+extern const struct bench bench_rename_base;
+extern const struct bench bench_rename_kprobe;
+extern const struct bench bench_rename_kretprobe;
+extern const struct bench bench_rename_rawtp;
+extern const struct bench bench_rename_fentry;
+extern const struct bench bench_rename_fexit;
+extern const struct bench bench_rename_fmodret;
static const struct bench *benchs[] = {
&bench_count_global,
&bench_count_local,
+ &bench_rename_base,
+ &bench_rename_kprobe,
+ &bench_rename_kretprobe,
+ &bench_rename_rawtp,
+ &bench_rename_fentry,
+ &bench_rename_fexit,
+ &bench_rename_fmodret,
};
static void setup_benchmark()
diff --git a/tools/testing/selftests/bpf/benchs/bench_rename.c b/tools/testing/selftests/bpf/benchs/bench_rename.c
new file mode 100644
index 000000000000..e74cff40f4fe
--- /dev/null
+++ b/tools/testing/selftests/bpf/benchs/bench_rename.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+#include <fcntl.h>
+#include "bench.h"
+#include "test_overhead.skel.h"
+
+/* BPF triggering benchmarks */
+static struct ctx {
+ struct test_overhead *skel;
+ struct counter hits;
+ int fd;
+} ctx;
+
+static void validate()
+{
+ if (env.producer_cnt != 1) {
+ fprintf(stderr, "benchmark doesn't support multi-producer!\n");
+ exit(1);
+ }
+ if (env.consumer_cnt != 1) {
+ fprintf(stderr, "benchmark doesn't support multi-consumer!\n");
+ exit(1);
+ }
+}
+
+static void *producer(void *input)
+{
+ char buf[] = "test_overhead";
+ int err;
+
+ while (true) {
+ err = write(ctx.fd, buf, sizeof(buf));
+ if (err < 0) {
+ fprintf(stderr, "write failed\n");
+ exit(1);
+ }
+ atomic_inc(&ctx.hits.value);
+ }
+}
+
+static void measure(struct bench_res *res)
+{
+ res->hits = atomic_swap(&ctx.hits.value, 0);
+}
+
+static void setup_ctx()
+{
+ setup_libbpf();
+
+ ctx.skel = test_overhead__open_and_load();
+ if (!ctx.skel) {
+ fprintf(stderr, "failed to open skeleton\n");
+ exit(1);
+ }
+
+ ctx.fd = open("/proc/self/comm", O_WRONLY|O_TRUNC);
+ if (ctx.fd < 0) {
+ fprintf(stderr, "failed to open /proc/self/comm: %d\n", -errno);
+ exit(1);
+ }
+}
+
+static void attach_bpf(struct bpf_program *prog)
+{
+ struct bpf_link *link;
+
+ link = bpf_program__attach(prog);
+ if (IS_ERR(link)) {
+ fprintf(stderr, "failed to attach program!\n");
+ exit(1);
+ }
+}
+
+static void setup_base()
+{
+ setup_ctx();
+}
+
+static void setup_kprobe()
+{
+ setup_ctx();
+ attach_bpf(ctx.skel->progs.prog1);
+}
+
+static void setup_kretprobe()
+{
+ setup_ctx();
+ attach_bpf(ctx.skel->progs.prog2);
+}
+
+static void setup_rawtp()
+{
+ setup_ctx();
+ attach_bpf(ctx.skel->progs.prog3);
+}
+
+static void setup_fentry()
+{
+ setup_ctx();
+ attach_bpf(ctx.skel->progs.prog4);
+}
+
+static void setup_fexit()
+{
+ setup_ctx();
+ attach_bpf(ctx.skel->progs.prog5);
+}
+
+static void setup_fmodret()
+{
+ setup_ctx();
+ attach_bpf(ctx.skel->progs.prog6);
+}
+
+static void *consumer(void *input)
+{
+ return NULL;
+}
+
+const struct bench bench_rename_base = {
+ .name = "rename-base",
+ .validate = validate,
+ .setup = setup_base,
+ .producer_thread = producer,
+ .consumer_thread = consumer,
+ .measure = measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_rename_kprobe = {
+ .name = "rename-kprobe",
+ .validate = validate,
+ .setup = setup_kprobe,
+ .producer_thread = producer,
+ .consumer_thread = consumer,
+ .measure = measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_rename_kretprobe = {
+ .name = "rename-kretprobe",
+ .validate = validate,
+ .setup = setup_kretprobe,
+ .producer_thread = producer,
+ .consumer_thread = consumer,
+ .measure = measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_rename_rawtp = {
+ .name = "rename-rawtp",
+ .validate = validate,
+ .setup = setup_rawtp,
+ .producer_thread = producer,
+ .consumer_thread = consumer,
+ .measure = measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_rename_fentry = {
+ .name = "rename-fentry",
+ .validate = validate,
+ .setup = setup_fentry,
+ .producer_thread = producer,
+ .consumer_thread = consumer,
+ .measure = measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_rename_fexit = {
+ .name = "rename-fexit",
+ .validate = validate,
+ .setup = setup_fexit,
+ .producer_thread = producer,
+ .consumer_thread = consumer,
+ .measure = measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_rename_fmodret = {
+ .name = "rename-fmodret",
+ .validate = validate,
+ .setup = setup_fmodret,
+ .producer_thread = producer,
+ .consumer_thread = consumer,
+ .measure = measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
diff --git a/tools/testing/selftests/bpf/benchs/run_bench_rename.sh b/tools/testing/selftests/bpf/benchs/run_bench_rename.sh
new file mode 100755
index 000000000000..16f774b1cdbe
--- /dev/null
+++ b/tools/testing/selftests/bpf/benchs/run_bench_rename.sh
@@ -0,0 +1,9 @@
+#!/bin/bash
+
+set -eufo pipefail
+
+for i in base kprobe kretprobe rawtp fentry fexit fmodret
+do
+ summary=$(sudo ./bench -w2 -d5 -a rename-$i | tail -n1 | cut -d'(' -f1 | cut -d' ' -f3-)
+ printf "%-10s: %s\n" $i "$summary"
+done
diff --git a/tools/testing/selftests/bpf/prog_tests/test_overhead.c b/tools/testing/selftests/bpf/prog_tests/test_overhead.c
index 465b371a561d..2702df2b2343 100644
--- a/tools/testing/selftests/bpf/prog_tests/test_overhead.c
+++ b/tools/testing/selftests/bpf/prog_tests/test_overhead.c
@@ -61,9 +61,10 @@ void test_test_overhead(void)
const char *raw_tp_name = "raw_tp/task_rename";
const char *fentry_name = "fentry/__set_task_comm";
const char *fexit_name = "fexit/__set_task_comm";
+ const char *fmodret_name = "fmod_ret/__set_task_comm";
const char *kprobe_func = "__set_task_comm";
struct bpf_program *kprobe_prog, *kretprobe_prog, *raw_tp_prog;
- struct bpf_program *fentry_prog, *fexit_prog;
+ struct bpf_program *fentry_prog, *fexit_prog, *fmodret_prog;
struct bpf_object *obj;
struct bpf_link *link;
int err, duration = 0;
@@ -96,6 +97,10 @@ void test_test_overhead(void)
if (CHECK(!fexit_prog, "find_probe",
"prog '%s' not found\n", fexit_name))
goto cleanup;
+ fmodret_prog = bpf_object__find_program_by_title(obj, fmodret_name);
+ if (CHECK(!fmodret_prog, "find_probe",
+ "prog '%s' not found\n", fmodret_name))
+ goto cleanup;
err = bpf_object__load(obj);
if (CHECK(err, "obj_load", "err %d\n", err))
@@ -142,6 +147,13 @@ void test_test_overhead(void)
goto cleanup;
test_run("fexit");
bpf_link__destroy(link);
+
+ /* attach fmod_ret */
+ link = bpf_program__attach_trace(fmodret_prog);
+ if (CHECK(IS_ERR(link), "attach fmod_ret", "err %ld\n", PTR_ERR(link)))
+ goto cleanup;
+ test_run("fmod_ret");
+ bpf_link__destroy(link);
cleanup:
prctl(PR_SET_NAME, comm, 0L, 0L, 0L);
bpf_object__close(obj);
diff --git a/tools/testing/selftests/bpf/progs/test_overhead.c b/tools/testing/selftests/bpf/progs/test_overhead.c
index 56a50b25cd33..450bf819beac 100644
--- a/tools/testing/selftests/bpf/progs/test_overhead.c
+++ b/tools/testing/selftests/bpf/progs/test_overhead.c
@@ -39,4 +39,10 @@ int BPF_PROG(prog5, struct task_struct *tsk, const char *buf, bool exec)
return !tsk;
}
+SEC("fmod_ret/__set_task_comm")
+int BPF_PROG(prog6, struct task_struct *tsk, const char *buf, bool exec)
+{
+ return !tsk;
+}
+
char _license[] SEC("license") = "GPL";
--
2.24.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH v3 bpf-next 3/4] selftest/bpf: fmod_ret prog and implement test_overhead as part of bench
2020-05-12 19:24 ` [PATCH v3 bpf-next 3/4] selftest/bpf: fmod_ret prog and implement test_overhead as part of bench Andrii Nakryiko
@ 2020-05-13 1:10 ` Yonghong Song
0 siblings, 0 replies; 9+ messages in thread
From: Yonghong Song @ 2020-05-13 1:10 UTC (permalink / raw)
To: Andrii Nakryiko, bpf, netdev, ast, daniel
Cc: andrii.nakryiko, kernel-team, John Fastabend
On 5/12/20 12:24 PM, Andrii Nakryiko wrote:
> Add fmod_ret BPF program to existing test_overhead selftest. Also re-implement
> user-space benchmarking part into benchmark runner to compare results. Results
> with ./bench are consistently somewhat lower than test_overhead's, but relative
> performance of various types of BPF programs stay consisten (e.g., kretprobe is
> noticeably slower). This slowdown seems to be coming from the fact that
> test_overhead is single-threaded, while benchmark always spins off at least
> one thread for producer. This has been confirmed by hacking multi-threaded
> test_overhead variant and also single-threaded bench variant. Resutls are
> below. run_bench_rename.sh script from benchs/ subdirectory was used to
> produce results for ./bench.
>
> Single-threaded implementations
> ===============================
>
> /* bench: single-threaded, atomics */
> base : 4.622 ± 0.049M/s
> kprobe : 3.673 ± 0.052M/s
> kretprobe : 2.625 ± 0.052M/s
> rawtp : 4.369 ± 0.089M/s
> fentry : 4.201 ± 0.558M/s
> fexit : 4.309 ± 0.148M/s
> fmodret : 4.314 ± 0.203M/s
>
> /* selftest: single-threaded, no atomics */
> task_rename base 4555K events per sec
> task_rename kprobe 3643K events per sec
> task_rename kretprobe 2506K events per sec
> task_rename raw_tp 4303K events per sec
> task_rename fentry 4307K events per sec
> task_rename fexit 4010K events per sec
> task_rename fmod_ret 3984K events per sec
>
> Multi-threaded implementations
> ==============================
>
> /* bench: multi-threaded w/ atomics */
> base : 3.910 ± 0.023M/s
> kprobe : 3.048 ± 0.037M/s
> kretprobe : 2.300 ± 0.015M/s
> rawtp : 3.687 ± 0.034M/s
> fentry : 3.740 ± 0.087M/s
> fexit : 3.510 ± 0.009M/s
> fmodret : 3.485 ± 0.050M/s
>
> /* selftest: multi-threaded w/ atomics */
> task_rename base 3872K events per sec
> task_rename kprobe 3068K events per sec
> task_rename kretprobe 2350K events per sec
> task_rename raw_tp 3731K events per sec
> task_rename fentry 3639K events per sec
> task_rename fexit 3558K events per sec
> task_rename fmod_ret 3511K events per sec
>
> /* selftest: multi-threaded, no atomics */
> task_rename base 3945K events per sec
> task_rename kprobe 3298K events per sec
> task_rename kretprobe 2451K events per sec
> task_rename raw_tp 3718K events per sec
> task_rename fentry 3782K events per sec
> task_rename fexit 3543K events per sec
> task_rename fmod_ret 3526K events per sec
>
> Note that the fact that ./bench benchmark always uses atomic increments for
> counting, while test_overhead doesn't, doesn't influence test results all that
> much.
>
> Acked-by: John Fastabend <john.fastabend@gmail.com>
> Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v3 bpf-next 4/4] selftest/bpf: add BPF triggering benchmark
2020-05-12 19:24 [PATCH v3 bpf-next 0/4] Add benchmark runner and few benchmarks Andrii Nakryiko
` (2 preceding siblings ...)
2020-05-12 19:24 ` [PATCH v3 bpf-next 3/4] selftest/bpf: fmod_ret prog and implement test_overhead as part of bench Andrii Nakryiko
@ 2020-05-12 19:24 ` Andrii Nakryiko
2020-05-13 19:23 ` [PATCH v3 bpf-next 0/4] Add benchmark runner and few benchmarks Alexei Starovoitov
4 siblings, 0 replies; 9+ messages in thread
From: Andrii Nakryiko @ 2020-05-12 19:24 UTC (permalink / raw)
To: bpf, netdev, ast, daniel
Cc: andrii.nakryiko, kernel-team, Andrii Nakryiko, John Fastabend,
Yonghong Song
It is sometimes desirable to be able to trigger BPF program from user-space
with minimal overhead. sys_enter would seem to be a good candidate, yet in
a lot of cases there will be a lot of noise from syscalls triggered by other
processes on the system. So while searching for low-overhead alternative, I've
stumbled upon getpgid() syscall, which seems to be specific enough to not
suffer from accidental syscall by other apps.
This set of benchmarks compares tp, raw_tp w/ filtering by syscall ID, kprobe,
fentry and fmod_ret with returning error (so that syscall would not be
executed), to determine the lowest-overhead way. Here are results on my
machine (using benchs/run_bench_trigger.sh script):
base : 9.200 ± 0.319M/s
tp : 6.690 ± 0.125M/s
rawtp : 8.571 ± 0.214M/s
kprobe : 6.431 ± 0.048M/s
fentry : 8.955 ± 0.241M/s
fmodret : 8.903 ± 0.135M/s
So it seems like fmodret doesn't give much benefit for such lightweight
syscall. Raw tracepoint is pretty decent despite additional filtering logic,
but it will be called for any other syscall in the system, which rules it out.
Fentry, though, seems to be adding the least amoung of overhead and achieves
97.3% of performance of baseline no-BPF-attached syscall.
Using getpgid() seems to be preferable to set_task_comm() approach from
test_overhead, as it's about 2.35x faster in a baseline performance.
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
tools/testing/selftests/bpf/Makefile | 4 +-
tools/testing/selftests/bpf/bench.c | 12 ++
.../selftests/bpf/benchs/bench_trigger.c | 167 ++++++++++++++++++
.../selftests/bpf/benchs/run_bench_trigger.sh | 9 +
.../selftests/bpf/progs/trigger_bench.c | 47 +++++
5 files changed, 238 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/bpf/benchs/bench_trigger.c
create mode 100755 tools/testing/selftests/bpf/benchs/run_bench_trigger.sh
create mode 100644 tools/testing/selftests/bpf/progs/trigger_bench.c
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 3c43d4eceba8..352d17a16bae 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -411,11 +411,13 @@ $(OUTPUT)/bench_%.o: benchs/bench_%.c bench.h
$(call msg,CC,,$@)
$(CC) $(CFLAGS) -c $(filter %.c,$^) $(LDLIBS) -o $@
$(OUTPUT)/bench_rename.o: $(OUTPUT)/test_overhead.skel.h
+$(OUTPUT)/bench_trigger.o: $(OUTPUT)/trigger_bench.skel.h
$(OUTPUT)/bench.o: bench.h testing_helpers.h
$(OUTPUT)/bench: LDLIBS += -lm
$(OUTPUT)/bench: $(OUTPUT)/bench.o $(OUTPUT)/testing_helpers.o \
$(OUTPUT)/bench_count.o \
- $(OUTPUT)/bench_rename.o
+ $(OUTPUT)/bench_rename.o \
+ $(OUTPUT)/bench_trigger.o
$(call msg,BINARY,,$@)
$(CC) $(LDFLAGS) -o $@ $(filter %.a %.o,$^) $(LDLIBS)
diff --git a/tools/testing/selftests/bpf/bench.c b/tools/testing/selftests/bpf/bench.c
index c9e8b7dbaf66..8c0dfbfe6088 100644
--- a/tools/testing/selftests/bpf/bench.c
+++ b/tools/testing/selftests/bpf/bench.c
@@ -304,6 +304,12 @@ extern const struct bench bench_rename_rawtp;
extern const struct bench bench_rename_fentry;
extern const struct bench bench_rename_fexit;
extern const struct bench bench_rename_fmodret;
+extern const struct bench bench_trig_base;
+extern const struct bench bench_trig_tp;
+extern const struct bench bench_trig_rawtp;
+extern const struct bench bench_trig_kprobe;
+extern const struct bench bench_trig_fentry;
+extern const struct bench bench_trig_fmodret;
static const struct bench *benchs[] = {
&bench_count_global,
@@ -315,6 +321,12 @@ static const struct bench *benchs[] = {
&bench_rename_fentry,
&bench_rename_fexit,
&bench_rename_fmodret,
+ &bench_trig_base,
+ &bench_trig_tp,
+ &bench_trig_rawtp,
+ &bench_trig_kprobe,
+ &bench_trig_fentry,
+ &bench_trig_fmodret,
};
static void setup_benchmark()
diff --git a/tools/testing/selftests/bpf/benchs/bench_trigger.c b/tools/testing/selftests/bpf/benchs/bench_trigger.c
new file mode 100644
index 000000000000..49c22832f216
--- /dev/null
+++ b/tools/testing/selftests/bpf/benchs/bench_trigger.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+#include "bench.h"
+#include "trigger_bench.skel.h"
+
+/* BPF triggering benchmarks */
+static struct trigger_ctx {
+ struct trigger_bench *skel;
+} ctx;
+
+static struct counter base_hits;
+
+static void trigger_validate()
+{
+ if (env.consumer_cnt != 1) {
+ fprintf(stderr, "benchmark doesn't support multi-consumer!\n");
+ exit(1);
+ }
+}
+
+static void *trigger_base_producer(void *input)
+{
+ while (true) {
+ (void)syscall(__NR_getpgid);
+ atomic_inc(&base_hits.value);
+ }
+ return NULL;
+}
+
+static void trigger_base_measure(struct bench_res *res)
+{
+ res->hits = atomic_swap(&base_hits.value, 0);
+}
+
+static void *trigger_producer(void *input)
+{
+ while (true)
+ (void)syscall(__NR_getpgid);
+ return NULL;
+}
+
+static void trigger_measure(struct bench_res *res)
+{
+ res->hits = atomic_swap(&ctx.skel->bss->hits, 0);
+}
+
+static void setup_ctx()
+{
+ setup_libbpf();
+
+ ctx.skel = trigger_bench__open_and_load();
+ if (!ctx.skel) {
+ fprintf(stderr, "failed to open skeleton\n");
+ exit(1);
+ }
+}
+
+static void attach_bpf(struct bpf_program *prog)
+{
+ struct bpf_link *link;
+
+ link = bpf_program__attach(prog);
+ if (IS_ERR(link)) {
+ fprintf(stderr, "failed to attach program!\n");
+ exit(1);
+ }
+}
+
+static void trigger_tp_setup()
+{
+ setup_ctx();
+ attach_bpf(ctx.skel->progs.bench_trigger_tp);
+}
+
+static void trigger_rawtp_setup()
+{
+ setup_ctx();
+ attach_bpf(ctx.skel->progs.bench_trigger_raw_tp);
+}
+
+static void trigger_kprobe_setup()
+{
+ setup_ctx();
+ attach_bpf(ctx.skel->progs.bench_trigger_kprobe);
+}
+
+static void trigger_fentry_setup()
+{
+ setup_ctx();
+ attach_bpf(ctx.skel->progs.bench_trigger_fentry);
+}
+
+static void trigger_fmodret_setup()
+{
+ setup_ctx();
+ attach_bpf(ctx.skel->progs.bench_trigger_fmodret);
+}
+
+static void *trigger_consumer(void *input)
+{
+ return NULL;
+}
+
+const struct bench bench_trig_base = {
+ .name = "trig-base",
+ .validate = trigger_validate,
+ .producer_thread = trigger_base_producer,
+ .consumer_thread = trigger_consumer,
+ .measure = trigger_base_measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_trig_tp = {
+ .name = "trig-tp",
+ .validate = trigger_validate,
+ .setup = trigger_tp_setup,
+ .producer_thread = trigger_producer,
+ .consumer_thread = trigger_consumer,
+ .measure = trigger_measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_trig_rawtp = {
+ .name = "trig-rawtp",
+ .validate = trigger_validate,
+ .setup = trigger_rawtp_setup,
+ .producer_thread = trigger_producer,
+ .consumer_thread = trigger_consumer,
+ .measure = trigger_measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_trig_kprobe = {
+ .name = "trig-kprobe",
+ .validate = trigger_validate,
+ .setup = trigger_kprobe_setup,
+ .producer_thread = trigger_producer,
+ .consumer_thread = trigger_consumer,
+ .measure = trigger_measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_trig_fentry = {
+ .name = "trig-fentry",
+ .validate = trigger_validate,
+ .setup = trigger_fentry_setup,
+ .producer_thread = trigger_producer,
+ .consumer_thread = trigger_consumer,
+ .measure = trigger_measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_trig_fmodret = {
+ .name = "trig-fmodret",
+ .validate = trigger_validate,
+ .setup = trigger_fmodret_setup,
+ .producer_thread = trigger_producer,
+ .consumer_thread = trigger_consumer,
+ .measure = trigger_measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
diff --git a/tools/testing/selftests/bpf/benchs/run_bench_trigger.sh b/tools/testing/selftests/bpf/benchs/run_bench_trigger.sh
new file mode 100755
index 000000000000..78e83f243294
--- /dev/null
+++ b/tools/testing/selftests/bpf/benchs/run_bench_trigger.sh
@@ -0,0 +1,9 @@
+#!/bin/bash
+
+set -eufo pipefail
+
+for i in base tp rawtp kprobe fentry fmodret
+do
+ summary=$(sudo ./bench -w2 -d5 -a trig-$i | tail -n1 | cut -d'(' -f1 | cut -d' ' -f3-)
+ printf "%-10s: %s\n" $i "$summary"
+done
diff --git a/tools/testing/selftests/bpf/progs/trigger_bench.c b/tools/testing/selftests/bpf/progs/trigger_bench.c
new file mode 100644
index 000000000000..8b36b6640e7e
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/trigger_bench.c
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2020 Facebook
+
+#include <linux/bpf.h>
+#include <asm/unistd.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+char _license[] SEC("license") = "GPL";
+
+long hits = 0;
+
+SEC("tp/syscalls/sys_enter_getpgid")
+int bench_trigger_tp(void *ctx)
+{
+ __sync_add_and_fetch(&hits, 1);
+ return 0;
+}
+
+SEC("raw_tp/sys_enter")
+int BPF_PROG(bench_trigger_raw_tp, struct pt_regs *regs, long id)
+{
+ if (id == __NR_getpgid)
+ __sync_add_and_fetch(&hits, 1);
+ return 0;
+}
+
+SEC("kprobe/__x64_sys_getpgid")
+int bench_trigger_kprobe(void *ctx)
+{
+ __sync_add_and_fetch(&hits, 1);
+ return 0;
+}
+
+SEC("fentry/__x64_sys_getpgid")
+int bench_trigger_fentry(void *ctx)
+{
+ __sync_add_and_fetch(&hits, 1);
+ return 0;
+}
+
+SEC("fmod_ret/__x64_sys_getpgid")
+int bench_trigger_fmodret(void *ctx)
+{
+ __sync_add_and_fetch(&hits, 1);
+ return -22;
+}
--
2.24.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH v3 bpf-next 0/4] Add benchmark runner and few benchmarks
2020-05-12 19:24 [PATCH v3 bpf-next 0/4] Add benchmark runner and few benchmarks Andrii Nakryiko
` (3 preceding siblings ...)
2020-05-12 19:24 ` [PATCH v3 bpf-next 4/4] selftest/bpf: add BPF triggering benchmark Andrii Nakryiko
@ 2020-05-13 19:23 ` Alexei Starovoitov
4 siblings, 0 replies; 9+ messages in thread
From: Alexei Starovoitov @ 2020-05-13 19:23 UTC (permalink / raw)
To: Andrii Nakryiko
Cc: bpf, Network Development, Alexei Starovoitov, Daniel Borkmann,
Andrii Nakryiko, Kernel Team
On Tue, May 12, 2020 at 12:47 PM Andrii Nakryiko <andriin@fb.com> wrote:
>
> Add generic benchmark runner framework which simplifies writing various
> performance benchmarks in a consistent fashion. This framework will be used
> in follow up patches to test performance of perf buffer and ring buffer as
> well.
>
> Patch #1 extracts parse_num_list to be re-used between test_progs and bench.
>
> Patch #2 adds generic runner implementation and atomic counter benchmarks to
> validate benchmark runner's behavior.
>
> Patch #3 implements test_overhead benchmark as part of bench runner. It also
> add fmod_ret BPF program type to a set of benchmarks.
>
> Patch #4 tests faster alternatives to set_task_comm() approach, tested in
> test_overhead, in search for minimal-overhead way to trigger BPF program
> execution from user-space on demand.
>
> v2->v3:
> - added --prod-affinity and --cons-affinity (Yonghong);
> - removed ringbuf-related options leftovers (Yonghong);
> - added more benchmarking results for test_overhead performance discrepancies;
Applied. Thanks
^ permalink raw reply [flat|nested] 9+ messages in thread