forked from mirrors/linux
		
	bpftool: Introduce "prog profile" command
With fentry/fexit programs, it is possible to profile BPF program with
hardware counters. Introduce bpftool "prog profile", which measures key
metrics of a BPF program.
bpftool prog profile command creates per-cpu perf events. Then it attaches
fentry/fexit programs to the target BPF program. The fentry program saves
perf event value to a map. The fexit program reads the perf event again,
and calculates the difference, which is the instructions/cycles used by
the target program.
Example input and output:
  ./bpftool prog profile id 337 duration 3 cycles instructions llc_misses
        4228 run_cnt
     3403698 cycles                                              (84.08%)
     3525294 instructions   #  1.04 insn per cycle               (84.05%)
          13 llc_misses     #  3.69 LLC misses per million isns  (83.50%)
This command measures cycles and instructions for BPF program with id
337 for 3 seconds. The program has triggered 4228 times. The rest of the
output is similar to perf-stat. In this example, the counters were only
counting ~84% of the time because of time multiplexing of perf counters.
Note that, this approach measures cycles and instructions in very small
increments. So the fentry/fexit programs introduce noticeable errors to
the measurement results.
The fentry/fexit programs are generated with BPF skeletons. Therefore, we
build bpftool twice. The first time _bpftool is built without skeletons.
Then, _bpftool is used to generate the skeletons. The second time, bpftool
is built with skeletons.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200309173218.2739965-2-songliubraving@fb.com
			
			
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					 5 changed files with 608 additions and 1 deletions
				
			
		|  | @ -59,6 +59,7 @@ LIBS = $(LIBBPF) -lelf -lz | |||
| 
 | ||||
| INSTALL ?= install | ||||
| RM ?= rm -f | ||||
| CLANG ?= clang | ||||
| 
 | ||||
| FEATURE_USER = .bpftool | ||||
| FEATURE_TESTS = libbfd disassembler-four-args reallocarray zlib | ||||
|  | @ -110,6 +111,22 @@ SRCS += $(BFD_SRCS) | |||
| endif | ||||
| 
 | ||||
| OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o | ||||
| _OBJS = $(filter-out $(OUTPUT)prog.o,$(OBJS)) $(OUTPUT)_prog.o | ||||
| 
 | ||||
| $(OUTPUT)_prog.o: prog.c | ||||
| 	$(QUIET_CC)$(COMPILE.c) -MMD -DBPFTOOL_WITHOUT_SKELETONS -o $@ $< | ||||
| 
 | ||||
| $(OUTPUT)_bpftool: $(_OBJS) $(LIBBPF) | ||||
| 	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(_OBJS) $(LIBS) | ||||
| 
 | ||||
| skeleton/profiler.bpf.o: skeleton/profiler.bpf.c | ||||
| 	$(QUIET_CLANG)$(CLANG) -I$(srctree)/tools/lib -g -O2 -target bpf -c $< -o $@ | ||||
| 
 | ||||
| profiler.skel.h: $(OUTPUT)_bpftool skeleton/profiler.bpf.o | ||||
| 	$(QUIET_GEN)$(OUTPUT)./_bpftool gen skeleton skeleton/profiler.bpf.o > $@ | ||||
| 
 | ||||
| $(OUTPUT)prog.o: prog.c profiler.skel.h | ||||
| 	$(QUIET_CC)$(COMPILE.c) -MMD -o $@ $< | ||||
| 
 | ||||
| $(OUTPUT)disasm.o: $(srctree)/kernel/bpf/disasm.c | ||||
| 	$(QUIET_CC)$(COMPILE.c) -MMD -o $@ $< | ||||
|  | @ -125,6 +142,7 @@ $(OUTPUT)%.o: %.c | |||
| clean: $(LIBBPF)-clean | ||||
| 	$(call QUIET_CLEAN, bpftool) | ||||
| 	$(Q)$(RM) -- $(OUTPUT)bpftool $(OUTPUT)*.o $(OUTPUT)*.d | ||||
| 	$(Q)$(RM) -- $(OUTPUT)_bpftool profiler.skel.h skeleton/profiler.bpf.o | ||||
| 	$(Q)$(RM) -r -- $(OUTPUT)libbpf/ | ||||
| 	$(call QUIET_CLEAN, core-gen) | ||||
| 	$(Q)$(RM) -- $(OUTPUT)FEATURE-DUMP.bpftool | ||||
|  |  | |||
|  | @ -4,6 +4,7 @@ | |||
| #define _GNU_SOURCE | ||||
| #include <errno.h> | ||||
| #include <fcntl.h> | ||||
| #include <signal.h> | ||||
| #include <stdarg.h> | ||||
| #include <stdio.h> | ||||
| #include <stdlib.h> | ||||
|  | @ -11,10 +12,13 @@ | |||
| #include <time.h> | ||||
| #include <unistd.h> | ||||
| #include <net/if.h> | ||||
| #include <sys/ioctl.h> | ||||
| #include <sys/types.h> | ||||
| #include <sys/stat.h> | ||||
| #include <sys/syscall.h> | ||||
| 
 | ||||
| #include <linux/err.h> | ||||
| #include <linux/perf_event.h> | ||||
| #include <linux/sizes.h> | ||||
| 
 | ||||
| #include <bpf/bpf.h> | ||||
|  | @ -1537,6 +1541,421 @@ static int do_loadall(int argc, char **argv) | |||
| 	return load_with_options(argc, argv, false); | ||||
| } | ||||
| 
 | ||||
| #ifdef BPFTOOL_WITHOUT_SKELETONS | ||||
| 
 | ||||
| static int do_profile(int argc, char **argv) | ||||
| { | ||||
| 	return 0; | ||||
| } | ||||
| 
 | ||||
| #else /* BPFTOOL_WITHOUT_SKELETONS */ | ||||
| 
 | ||||
| #include "profiler.skel.h" | ||||
| 
 | ||||
| struct profile_metric { | ||||
| 	const char *name; | ||||
| 	struct bpf_perf_event_value val; | ||||
| 	struct perf_event_attr attr; | ||||
| 	bool selected; | ||||
| 
 | ||||
| 	/* calculate ratios like instructions per cycle */ | ||||
| 	const int ratio_metric; /* 0 for N/A, 1 for index 0 (cycles) */ | ||||
| 	const char *ratio_desc; | ||||
| 	const float ratio_mul; | ||||
| } metrics[] = { | ||||
| 	{ | ||||
| 		.name = "cycles", | ||||
| 		.attr = { | ||||
| 			.type = PERF_TYPE_HARDWARE, | ||||
| 			.config = PERF_COUNT_HW_CPU_CYCLES, | ||||
| 			.exclude_user = 1, | ||||
| 		}, | ||||
| 	}, | ||||
| 	{ | ||||
| 		.name = "instructions", | ||||
| 		.attr = { | ||||
| 			.type = PERF_TYPE_HARDWARE, | ||||
| 			.config = PERF_COUNT_HW_INSTRUCTIONS, | ||||
| 			.exclude_user = 1, | ||||
| 		}, | ||||
| 		.ratio_metric = 1, | ||||
| 		.ratio_desc = "insns per cycle", | ||||
| 		.ratio_mul = 1.0, | ||||
| 	}, | ||||
| 	{ | ||||
| 		.name = "l1d_loads", | ||||
| 		.attr = { | ||||
| 			.type = PERF_TYPE_HW_CACHE, | ||||
| 			.config = | ||||
| 				PERF_COUNT_HW_CACHE_L1D | | ||||
| 				(PERF_COUNT_HW_CACHE_OP_READ << 8) | | ||||
| 				(PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16), | ||||
| 			.exclude_user = 1, | ||||
| 		}, | ||||
| 	}, | ||||
| 	{ | ||||
| 		.name = "llc_misses", | ||||
| 		.attr = { | ||||
| 			.type = PERF_TYPE_HW_CACHE, | ||||
| 			.config = | ||||
| 				PERF_COUNT_HW_CACHE_LL | | ||||
| 				(PERF_COUNT_HW_CACHE_OP_READ << 8) | | ||||
| 				(PERF_COUNT_HW_CACHE_RESULT_MISS << 16), | ||||
| 			.exclude_user = 1 | ||||
| 		}, | ||||
| 		.ratio_metric = 2, | ||||
| 		.ratio_desc = "LLC misses per million insns", | ||||
| 		.ratio_mul = 1e6, | ||||
| 	}, | ||||
| }; | ||||
| 
 | ||||
| static __u64 profile_total_count; | ||||
| 
 | ||||
| #define MAX_NUM_PROFILE_METRICS 4 | ||||
| 
 | ||||
| static int profile_parse_metrics(int argc, char **argv) | ||||
| { | ||||
| 	unsigned int metric_cnt; | ||||
| 	int selected_cnt = 0; | ||||
| 	unsigned int i; | ||||
| 
 | ||||
| 	metric_cnt = sizeof(metrics) / sizeof(struct profile_metric); | ||||
| 
 | ||||
| 	while (argc > 0) { | ||||
| 		for (i = 0; i < metric_cnt; i++) { | ||||
| 			if (is_prefix(argv[0], metrics[i].name)) { | ||||
| 				if (!metrics[i].selected) | ||||
| 					selected_cnt++; | ||||
| 				metrics[i].selected = true; | ||||
| 				break; | ||||
| 			} | ||||
| 		} | ||||
| 		if (i == metric_cnt) { | ||||
| 			p_err("unknown metric %s", argv[0]); | ||||
| 			return -1; | ||||
| 		} | ||||
| 		NEXT_ARG(); | ||||
| 	} | ||||
| 	if (selected_cnt > MAX_NUM_PROFILE_METRICS) { | ||||
| 		p_err("too many (%d) metrics, please specify no more than %d metrics at at time", | ||||
| 		      selected_cnt, MAX_NUM_PROFILE_METRICS); | ||||
| 		return -1; | ||||
| 	} | ||||
| 	return selected_cnt; | ||||
| } | ||||
| 
 | ||||
| static void profile_read_values(struct profiler_bpf *obj) | ||||
| { | ||||
| 	__u32 m, cpu, num_cpu = obj->rodata->num_cpu; | ||||
| 	int reading_map_fd, count_map_fd; | ||||
| 	__u64 counts[num_cpu]; | ||||
| 	__u32 key = 0; | ||||
| 	int err; | ||||
| 
 | ||||
| 	reading_map_fd = bpf_map__fd(obj->maps.accum_readings); | ||||
| 	count_map_fd = bpf_map__fd(obj->maps.counts); | ||||
| 	if (reading_map_fd < 0 || count_map_fd < 0) { | ||||
| 		p_err("failed to get fd for map"); | ||||
| 		return; | ||||
| 	} | ||||
| 
 | ||||
| 	err = bpf_map_lookup_elem(count_map_fd, &key, counts); | ||||
| 	if (err) { | ||||
| 		p_err("failed to read count_map: %s", strerror(errno)); | ||||
| 		return; | ||||
| 	} | ||||
| 
 | ||||
| 	profile_total_count = 0; | ||||
| 	for (cpu = 0; cpu < num_cpu; cpu++) | ||||
| 		profile_total_count += counts[cpu]; | ||||
| 
 | ||||
| 	for (m = 0; m < ARRAY_SIZE(metrics); m++) { | ||||
| 		struct bpf_perf_event_value values[num_cpu]; | ||||
| 
 | ||||
| 		if (!metrics[m].selected) | ||||
| 			continue; | ||||
| 
 | ||||
| 		err = bpf_map_lookup_elem(reading_map_fd, &key, values); | ||||
| 		if (err) { | ||||
| 			p_err("failed to read reading_map: %s", | ||||
| 			      strerror(errno)); | ||||
| 			return; | ||||
| 		} | ||||
| 		for (cpu = 0; cpu < num_cpu; cpu++) { | ||||
| 			metrics[m].val.counter += values[cpu].counter; | ||||
| 			metrics[m].val.enabled += values[cpu].enabled; | ||||
| 			metrics[m].val.running += values[cpu].running; | ||||
| 		} | ||||
| 		key++; | ||||
| 	} | ||||
| } | ||||
| 
 | ||||
| static void profile_print_readings_json(void) | ||||
| { | ||||
| 	__u32 m; | ||||
| 
 | ||||
| 	jsonw_start_array(json_wtr); | ||||
| 	for (m = 0; m < ARRAY_SIZE(metrics); m++) { | ||||
| 		if (!metrics[m].selected) | ||||
| 			continue; | ||||
| 		jsonw_start_object(json_wtr); | ||||
| 		jsonw_string_field(json_wtr, "metric", metrics[m].name); | ||||
| 		jsonw_lluint_field(json_wtr, "run_cnt", profile_total_count); | ||||
| 		jsonw_lluint_field(json_wtr, "value", metrics[m].val.counter); | ||||
| 		jsonw_lluint_field(json_wtr, "enabled", metrics[m].val.enabled); | ||||
| 		jsonw_lluint_field(json_wtr, "running", metrics[m].val.running); | ||||
| 
 | ||||
| 		jsonw_end_object(json_wtr); | ||||
| 	} | ||||
| 	jsonw_end_array(json_wtr); | ||||
| } | ||||
| 
 | ||||
| static void profile_print_readings_plain(void) | ||||
| { | ||||
| 	__u32 m; | ||||
| 
 | ||||
| 	printf("\n%18llu %-20s\n", profile_total_count, "run_cnt"); | ||||
| 	for (m = 0; m < ARRAY_SIZE(metrics); m++) { | ||||
| 		struct bpf_perf_event_value *val = &metrics[m].val; | ||||
| 		int r; | ||||
| 
 | ||||
| 		if (!metrics[m].selected) | ||||
| 			continue; | ||||
| 		printf("%18llu %-20s", val->counter, metrics[m].name); | ||||
| 
 | ||||
| 		r = metrics[m].ratio_metric - 1; | ||||
| 		if (r >= 0 && metrics[r].selected && | ||||
| 		    metrics[r].val.counter > 0) { | ||||
| 			printf("# %8.2f %-30s", | ||||
| 			       val->counter * metrics[m].ratio_mul / | ||||
| 			       metrics[r].val.counter, | ||||
| 			       metrics[m].ratio_desc); | ||||
| 		} else { | ||||
| 			printf("%-41s", ""); | ||||
| 		} | ||||
| 
 | ||||
| 		if (val->enabled > val->running) | ||||
| 			printf("(%4.2f%%)", | ||||
| 			       val->running * 100.0 / val->enabled); | ||||
| 		printf("\n"); | ||||
| 	} | ||||
| } | ||||
| 
 | ||||
| static void profile_print_readings(void) | ||||
| { | ||||
| 	if (json_output) | ||||
| 		profile_print_readings_json(); | ||||
| 	else | ||||
| 		profile_print_readings_plain(); | ||||
| } | ||||
| 
 | ||||
| static char *profile_target_name(int tgt_fd) | ||||
| { | ||||
| 	struct bpf_prog_info_linear *info_linear; | ||||
| 	struct bpf_func_info *func_info; | ||||
| 	const struct btf_type *t; | ||||
| 	char *name = NULL; | ||||
| 	struct btf *btf; | ||||
| 
 | ||||
| 	info_linear = bpf_program__get_prog_info_linear( | ||||
| 		tgt_fd, 1UL << BPF_PROG_INFO_FUNC_INFO); | ||||
| 	if (IS_ERR_OR_NULL(info_linear)) { | ||||
| 		p_err("failed to get info_linear for prog FD %d", tgt_fd); | ||||
| 		return NULL; | ||||
| 	} | ||||
| 
 | ||||
| 	if (info_linear->info.btf_id == 0 || | ||||
| 	    btf__get_from_id(info_linear->info.btf_id, &btf)) { | ||||
| 		p_err("prog FD %d doesn't have valid btf", tgt_fd); | ||||
| 		goto out; | ||||
| 	} | ||||
| 
 | ||||
| 	func_info = (struct bpf_func_info *)(info_linear->info.func_info); | ||||
| 	t = btf__type_by_id(btf, func_info[0].type_id); | ||||
| 	if (!t) { | ||||
| 		p_err("btf %d doesn't have type %d", | ||||
| 		      info_linear->info.btf_id, func_info[0].type_id); | ||||
| 		goto out; | ||||
| 	} | ||||
| 	name = strdup(btf__name_by_offset(btf, t->name_off)); | ||||
| out: | ||||
| 	free(info_linear); | ||||
| 	return name; | ||||
| } | ||||
| 
 | ||||
| static struct profiler_bpf *profile_obj; | ||||
| static int profile_tgt_fd = -1; | ||||
| static char *profile_tgt_name; | ||||
| static int *profile_perf_events; | ||||
| static int profile_perf_event_cnt; | ||||
| 
 | ||||
| static void profile_close_perf_events(struct profiler_bpf *obj) | ||||
| { | ||||
| 	int i; | ||||
| 
 | ||||
| 	for (i = profile_perf_event_cnt - 1; i >= 0; i--) | ||||
| 		close(profile_perf_events[i]); | ||||
| 
 | ||||
| 	free(profile_perf_events); | ||||
| 	profile_perf_event_cnt = 0; | ||||
| } | ||||
| 
 | ||||
| static int profile_open_perf_events(struct profiler_bpf *obj) | ||||
| { | ||||
| 	unsigned int cpu, m; | ||||
| 	int map_fd, pmu_fd; | ||||
| 
 | ||||
| 	profile_perf_events = calloc( | ||||
| 		sizeof(int), obj->rodata->num_cpu * obj->rodata->num_metric); | ||||
| 	if (!profile_perf_events) { | ||||
| 		p_err("failed to allocate memory for perf_event array: %s", | ||||
| 		      strerror(errno)); | ||||
| 		return -1; | ||||
| 	} | ||||
| 	map_fd = bpf_map__fd(obj->maps.events); | ||||
| 	if (map_fd < 0) { | ||||
| 		p_err("failed to get fd for events map"); | ||||
| 		return -1; | ||||
| 	} | ||||
| 
 | ||||
| 	for (m = 0; m < ARRAY_SIZE(metrics); m++) { | ||||
| 		if (!metrics[m].selected) | ||||
| 			continue; | ||||
| 		for (cpu = 0; cpu < obj->rodata->num_cpu; cpu++) { | ||||
| 			pmu_fd = syscall(__NR_perf_event_open, &metrics[m].attr, | ||||
| 					 -1/*pid*/, cpu, -1/*group_fd*/, 0); | ||||
| 			if (pmu_fd < 0 || | ||||
| 			    bpf_map_update_elem(map_fd, &profile_perf_event_cnt, | ||||
| 						&pmu_fd, BPF_ANY) || | ||||
| 			    ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0)) { | ||||
| 				p_err("failed to create event %s on cpu %d", | ||||
| 				      metrics[m].name, cpu); | ||||
| 				return -1; | ||||
| 			} | ||||
| 			profile_perf_events[profile_perf_event_cnt++] = pmu_fd; | ||||
| 		} | ||||
| 	} | ||||
| 	return 0; | ||||
| } | ||||
| 
 | ||||
| static void profile_print_and_cleanup(void) | ||||
| { | ||||
| 	profile_close_perf_events(profile_obj); | ||||
| 	profile_read_values(profile_obj); | ||||
| 	profile_print_readings(); | ||||
| 	profiler_bpf__destroy(profile_obj); | ||||
| 
 | ||||
| 	close(profile_tgt_fd); | ||||
| 	free(profile_tgt_name); | ||||
| } | ||||
| 
 | ||||
| static void int_exit(int signo) | ||||
| { | ||||
| 	profile_print_and_cleanup(); | ||||
| 	exit(0); | ||||
| } | ||||
| 
 | ||||
| static int do_profile(int argc, char **argv) | ||||
| { | ||||
| 	int num_metric, num_cpu, err = -1; | ||||
| 	struct bpf_program *prog; | ||||
| 	unsigned long duration; | ||||
| 	char *endptr; | ||||
| 
 | ||||
| 	/* we at least need two args for the prog and one metric */ | ||||
| 	if (!REQ_ARGS(3)) | ||||
| 		return -EINVAL; | ||||
| 
 | ||||
| 	/* parse target fd */ | ||||
| 	profile_tgt_fd = prog_parse_fd(&argc, &argv); | ||||
| 	if (profile_tgt_fd < 0) { | ||||
| 		p_err("failed to parse fd"); | ||||
| 		return -1; | ||||
| 	} | ||||
| 
 | ||||
| 	/* parse profiling optional duration */ | ||||
| 	if (argc > 2 && is_prefix(argv[0], "duration")) { | ||||
| 		NEXT_ARG(); | ||||
| 		duration = strtoul(*argv, &endptr, 0); | ||||
| 		if (*endptr) | ||||
| 			usage(); | ||||
| 		NEXT_ARG(); | ||||
| 	} else { | ||||
| 		duration = UINT_MAX; | ||||
| 	} | ||||
| 
 | ||||
| 	num_metric = profile_parse_metrics(argc, argv); | ||||
| 	if (num_metric <= 0) | ||||
| 		goto out; | ||||
| 
 | ||||
| 	num_cpu = libbpf_num_possible_cpus(); | ||||
| 	if (num_cpu <= 0) { | ||||
| 		p_err("failed to identify number of CPUs"); | ||||
| 		goto out; | ||||
| 	} | ||||
| 
 | ||||
| 	profile_obj = profiler_bpf__open(); | ||||
| 	if (!profile_obj) { | ||||
| 		p_err("failed to open and/or load BPF object"); | ||||
| 		goto out; | ||||
| 	} | ||||
| 
 | ||||
| 	profile_obj->rodata->num_cpu = num_cpu; | ||||
| 	profile_obj->rodata->num_metric = num_metric; | ||||
| 
 | ||||
| 	/* adjust map sizes */ | ||||
| 	bpf_map__resize(profile_obj->maps.events, num_metric * num_cpu); | ||||
| 	bpf_map__resize(profile_obj->maps.fentry_readings, num_metric); | ||||
| 	bpf_map__resize(profile_obj->maps.accum_readings, num_metric); | ||||
| 	bpf_map__resize(profile_obj->maps.counts, 1); | ||||
| 
 | ||||
| 	/* change target name */ | ||||
| 	profile_tgt_name = profile_target_name(profile_tgt_fd); | ||||
| 	if (!profile_tgt_name) | ||||
| 		goto out; | ||||
| 
 | ||||
| 	bpf_object__for_each_program(prog, profile_obj->obj) { | ||||
| 		err = bpf_program__set_attach_target(prog, profile_tgt_fd, | ||||
| 						     profile_tgt_name); | ||||
| 		if (err) { | ||||
| 			p_err("failed to set attach target\n"); | ||||
| 			goto out; | ||||
| 		} | ||||
| 	} | ||||
| 
 | ||||
| 	set_max_rlimit(); | ||||
| 	err = profiler_bpf__load(profile_obj); | ||||
| 	if (err) { | ||||
| 		p_err("failed to load profile_obj"); | ||||
| 		goto out; | ||||
| 	} | ||||
| 
 | ||||
| 	err = profile_open_perf_events(profile_obj); | ||||
| 	if (err) | ||||
| 		goto out; | ||||
| 
 | ||||
| 	err = profiler_bpf__attach(profile_obj); | ||||
| 	if (err) { | ||||
| 		p_err("failed to attach profile_obj"); | ||||
| 		goto out; | ||||
| 	} | ||||
| 	signal(SIGINT, int_exit); | ||||
| 
 | ||||
| 	sleep(duration); | ||||
| 	profile_print_and_cleanup(); | ||||
| 	return 0; | ||||
| 
 | ||||
| out: | ||||
| 	profile_close_perf_events(profile_obj); | ||||
| 	if (profile_obj) | ||||
| 		profiler_bpf__destroy(profile_obj); | ||||
| 	close(profile_tgt_fd); | ||||
| 	free(profile_tgt_name); | ||||
| 	return err; | ||||
| } | ||||
| 
 | ||||
| #endif /* BPFTOOL_WITHOUT_SKELETONS */ | ||||
| 
 | ||||
| static int do_help(int argc, char **argv) | ||||
| { | ||||
| 	if (json_output) { | ||||
|  | @ -1560,6 +1979,7 @@ static int do_help(int argc, char **argv) | |||
| 		"                         [data_out FILE [data_size_out L]] \\\n" | ||||
| 		"                         [ctx_in FILE [ctx_out FILE [ctx_size_out M]]] \\\n" | ||||
| 		"                         [repeat N]\n" | ||||
| 		"       %s %s profile PROG [duration DURATION] METRICs\n" | ||||
| 		"       %s %s tracelog\n" | ||||
| 		"       %s %s help\n" | ||||
| 		"\n" | ||||
|  | @ -1577,12 +1997,13 @@ static int do_help(int argc, char **argv) | |||
| 		"                 struct_ops | fentry | fexit | freplace }\n" | ||||
| 		"       ATTACH_TYPE := { msg_verdict | stream_verdict | stream_parser |\n" | ||||
| 		"                        flow_dissector }\n" | ||||
| 		"       METRIC := { cycles | instructions | l1d_loads | llc_misses }\n" | ||||
| 		"       " HELP_SPEC_OPTIONS "\n" | ||||
| 		"", | ||||
| 		bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], | ||||
| 		bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], | ||||
| 		bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2], | ||||
| 		bin_name, argv[-2]); | ||||
| 		bin_name, argv[-2], bin_name, argv[-2]); | ||||
| 
 | ||||
| 	return 0; | ||||
| } | ||||
|  | @ -1599,6 +2020,7 @@ static const struct cmd cmds[] = { | |||
| 	{ "detach",	do_detach }, | ||||
| 	{ "tracelog",	do_tracelog }, | ||||
| 	{ "run",	do_run }, | ||||
| 	{ "profile",	do_profile }, | ||||
| 	{ 0 } | ||||
| }; | ||||
| 
 | ||||
|  |  | |||
							
								
								
									
										119
									
								
								tools/bpf/bpftool/skeleton/profiler.bpf.c
									
									
									
									
									
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										119
									
								
								tools/bpf/bpftool/skeleton/profiler.bpf.c
									
									
									
									
									
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							|  | @ -0,0 +1,119 @@ | |||
| // SPDX-License-Identifier: GPL-2.0
 | ||||
| // Copyright (c) 2020 Facebook
 | ||||
| #include "profiler.h" | ||||
| #include <linux/bpf.h> | ||||
| #include <bpf/bpf_helpers.h> | ||||
| #include <bpf/bpf_tracing.h> | ||||
| 
 | ||||
| /* map of perf event fds, num_cpu * num_metric entries */ | ||||
| struct { | ||||
| 	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY); | ||||
| 	__uint(key_size, sizeof(u32)); | ||||
| 	__uint(value_size, sizeof(int)); | ||||
| } events SEC(".maps"); | ||||
| 
 | ||||
| /* readings at fentry */ | ||||
| struct { | ||||
| 	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); | ||||
| 	__uint(key_size, sizeof(u32)); | ||||
| 	__uint(value_size, sizeof(struct bpf_perf_event_value)); | ||||
| } fentry_readings SEC(".maps"); | ||||
| 
 | ||||
| /* accumulated readings */ | ||||
| struct { | ||||
| 	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); | ||||
| 	__uint(key_size, sizeof(u32)); | ||||
| 	__uint(value_size, sizeof(struct bpf_perf_event_value)); | ||||
| } accum_readings SEC(".maps"); | ||||
| 
 | ||||
| /* sample counts, one per cpu */ | ||||
| struct { | ||||
| 	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); | ||||
| 	__uint(key_size, sizeof(u32)); | ||||
| 	__uint(value_size, sizeof(u64)); | ||||
| } counts SEC(".maps"); | ||||
| 
 | ||||
| const volatile __u32 num_cpu = 1; | ||||
| const volatile __u32 num_metric = 1; | ||||
| #define MAX_NUM_MATRICS 4 | ||||
| 
 | ||||
| SEC("fentry/XXX") | ||||
| int BPF_PROG(fentry_XXX) | ||||
| { | ||||
| 	struct bpf_perf_event_value *ptrs[MAX_NUM_MATRICS]; | ||||
| 	u32 key = bpf_get_smp_processor_id(); | ||||
| 	u32 i; | ||||
| 
 | ||||
| 	/* look up before reading, to reduce error */ | ||||
| 	for (i = 0; i < num_metric && i < MAX_NUM_MATRICS; i++) { | ||||
| 		u32 flag = i; | ||||
| 
 | ||||
| 		ptrs[i] = bpf_map_lookup_elem(&fentry_readings, &flag); | ||||
| 		if (!ptrs[i]) | ||||
| 			return 0; | ||||
| 	} | ||||
| 
 | ||||
| 	for (i = 0; i < num_metric && i < MAX_NUM_MATRICS; i++) { | ||||
| 		struct bpf_perf_event_value reading; | ||||
| 		int err; | ||||
| 
 | ||||
| 		err = bpf_perf_event_read_value(&events, key, &reading, | ||||
| 						sizeof(reading)); | ||||
| 		if (err) | ||||
| 			return 0; | ||||
| 		*(ptrs[i]) = reading; | ||||
| 		key += num_cpu; | ||||
| 	} | ||||
| 
 | ||||
| 	return 0; | ||||
| } | ||||
| 
 | ||||
| static inline void | ||||
| fexit_update_maps(u32 id, struct bpf_perf_event_value *after) | ||||
| { | ||||
| 	struct bpf_perf_event_value *before, diff, *accum; | ||||
| 
 | ||||
| 	before = bpf_map_lookup_elem(&fentry_readings, &id); | ||||
| 	/* only account samples with a valid fentry_reading */ | ||||
| 	if (before && before->counter) { | ||||
| 		struct bpf_perf_event_value *accum; | ||||
| 
 | ||||
| 		diff.counter = after->counter - before->counter; | ||||
| 		diff.enabled = after->enabled - before->enabled; | ||||
| 		diff.running = after->running - before->running; | ||||
| 
 | ||||
| 		accum = bpf_map_lookup_elem(&accum_readings, &id); | ||||
| 		if (accum) { | ||||
| 			accum->counter += diff.counter; | ||||
| 			accum->enabled += diff.enabled; | ||||
| 			accum->running += diff.running; | ||||
| 		} | ||||
| 	} | ||||
| } | ||||
| 
 | ||||
| SEC("fexit/XXX") | ||||
| int BPF_PROG(fexit_XXX) | ||||
| { | ||||
| 	struct bpf_perf_event_value readings[MAX_NUM_MATRICS]; | ||||
| 	u32 cpu = bpf_get_smp_processor_id(); | ||||
| 	u32 i, one = 1, zero = 0; | ||||
| 	int err; | ||||
| 	u64 *count; | ||||
| 
 | ||||
| 	/* read all events before updating the maps, to reduce error */ | ||||
| 	for (i = 0; i < num_metric && i < MAX_NUM_MATRICS; i++) { | ||||
| 		err = bpf_perf_event_read_value(&events, cpu + i * num_cpu, | ||||
| 						readings + i, sizeof(*readings)); | ||||
| 		if (err) | ||||
| 			return 0; | ||||
| 	} | ||||
| 	count = bpf_map_lookup_elem(&counts, &zero); | ||||
| 	if (count) { | ||||
| 		*count += 1; | ||||
| 		for (i = 0; i < num_metric && i < MAX_NUM_MATRICS; i++) | ||||
| 			fexit_update_maps(i, &readings[i]); | ||||
| 	} | ||||
| 	return 0; | ||||
| } | ||||
| 
 | ||||
| char LICENSE[] SEC("license") = "GPL"; | ||||
							
								
								
									
										47
									
								
								tools/bpf/bpftool/skeleton/profiler.h
									
									
									
									
									
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								tools/bpf/bpftool/skeleton/profiler.h
									
									
									
									
									
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							|  | @ -0,0 +1,47 @@ | |||
| /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ | ||||
| #ifndef __PROFILER_H | ||||
| #define __PROFILER_H | ||||
| 
 | ||||
| /* useful typedefs from vmlinux.h */ | ||||
| 
 | ||||
| typedef signed char __s8; | ||||
| typedef unsigned char __u8; | ||||
| typedef short int __s16; | ||||
| typedef short unsigned int __u16; | ||||
| typedef int __s32; | ||||
| typedef unsigned int __u32; | ||||
| typedef long long int __s64; | ||||
| typedef long long unsigned int __u64; | ||||
| 
 | ||||
| typedef __s8 s8; | ||||
| typedef __u8 u8; | ||||
| typedef __s16 s16; | ||||
| typedef __u16 u16; | ||||
| typedef __s32 s32; | ||||
| typedef __u32 u32; | ||||
| typedef __s64 s64; | ||||
| typedef __u64 u64; | ||||
| 
 | ||||
| enum { | ||||
| 	false = 0, | ||||
| 	true = 1, | ||||
| }; | ||||
| 
 | ||||
| #ifdef __CHECKER__ | ||||
| #define __bitwise__ __attribute__((bitwise)) | ||||
| #else | ||||
| #define __bitwise__ | ||||
| #endif | ||||
| #define __bitwise __bitwise__ | ||||
| 
 | ||||
| typedef __u16 __bitwise __le16; | ||||
| typedef __u16 __bitwise __be16; | ||||
| typedef __u32 __bitwise __le32; | ||||
| typedef __u32 __bitwise __be32; | ||||
| typedef __u64 __bitwise __le64; | ||||
| typedef __u64 __bitwise __be64; | ||||
| 
 | ||||
| typedef __u16 __bitwise __sum16; | ||||
| typedef __u32 __bitwise __wsum; | ||||
| 
 | ||||
| #endif /* __PROFILER_H */ | ||||
|  | @ -106,6 +106,7 @@ ifneq ($(silent),1) | |||
|   ifneq ($(V),1) | ||||
| 	QUIET_CC       = @echo '  CC       '$@; | ||||
| 	QUIET_CC_FPIC  = @echo '  CC FPIC  '$@; | ||||
| 	QUIET_CLANG    = @echo '  CLANG    '$@; | ||||
| 	QUIET_AR       = @echo '  AR       '$@; | ||||
| 	QUIET_LINK     = @echo '  LINK     '$@; | ||||
| 	QUIET_MKDIR    = @echo '  MKDIR    '$@; | ||||
|  |  | |||
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