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	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 | INSTALL ?= install | ||||||
| RM ?= rm -f | RM ?= rm -f | ||||||
|  | CLANG ?= clang | ||||||
| 
 | 
 | ||||||
| FEATURE_USER = .bpftool | FEATURE_USER = .bpftool | ||||||
| FEATURE_TESTS = libbfd disassembler-four-args reallocarray zlib | FEATURE_TESTS = libbfd disassembler-four-args reallocarray zlib | ||||||
|  | @ -110,6 +111,22 @@ SRCS += $(BFD_SRCS) | ||||||
| endif | endif | ||||||
| 
 | 
 | ||||||
| OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o | 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 | $(OUTPUT)disasm.o: $(srctree)/kernel/bpf/disasm.c | ||||||
| 	$(QUIET_CC)$(COMPILE.c) -MMD -o $@ $< | 	$(QUIET_CC)$(COMPILE.c) -MMD -o $@ $< | ||||||
|  | @ -125,6 +142,7 @@ $(OUTPUT)%.o: %.c | ||||||
| clean: $(LIBBPF)-clean | clean: $(LIBBPF)-clean | ||||||
| 	$(call QUIET_CLEAN, bpftool) | 	$(call QUIET_CLEAN, bpftool) | ||||||
| 	$(Q)$(RM) -- $(OUTPUT)bpftool $(OUTPUT)*.o $(OUTPUT)*.d | 	$(Q)$(RM) -- $(OUTPUT)bpftool $(OUTPUT)*.o $(OUTPUT)*.d | ||||||
|  | 	$(Q)$(RM) -- $(OUTPUT)_bpftool profiler.skel.h skeleton/profiler.bpf.o | ||||||
| 	$(Q)$(RM) -r -- $(OUTPUT)libbpf/ | 	$(Q)$(RM) -r -- $(OUTPUT)libbpf/ | ||||||
| 	$(call QUIET_CLEAN, core-gen) | 	$(call QUIET_CLEAN, core-gen) | ||||||
| 	$(Q)$(RM) -- $(OUTPUT)FEATURE-DUMP.bpftool | 	$(Q)$(RM) -- $(OUTPUT)FEATURE-DUMP.bpftool | ||||||
|  |  | ||||||
|  | @ -4,6 +4,7 @@ | ||||||
| #define _GNU_SOURCE | #define _GNU_SOURCE | ||||||
| #include <errno.h> | #include <errno.h> | ||||||
| #include <fcntl.h> | #include <fcntl.h> | ||||||
|  | #include <signal.h> | ||||||
| #include <stdarg.h> | #include <stdarg.h> | ||||||
| #include <stdio.h> | #include <stdio.h> | ||||||
| #include <stdlib.h> | #include <stdlib.h> | ||||||
|  | @ -11,10 +12,13 @@ | ||||||
| #include <time.h> | #include <time.h> | ||||||
| #include <unistd.h> | #include <unistd.h> | ||||||
| #include <net/if.h> | #include <net/if.h> | ||||||
|  | #include <sys/ioctl.h> | ||||||
| #include <sys/types.h> | #include <sys/types.h> | ||||||
| #include <sys/stat.h> | #include <sys/stat.h> | ||||||
|  | #include <sys/syscall.h> | ||||||
| 
 | 
 | ||||||
| #include <linux/err.h> | #include <linux/err.h> | ||||||
|  | #include <linux/perf_event.h> | ||||||
| #include <linux/sizes.h> | #include <linux/sizes.h> | ||||||
| 
 | 
 | ||||||
| #include <bpf/bpf.h> | #include <bpf/bpf.h> | ||||||
|  | @ -1537,6 +1541,421 @@ static int do_loadall(int argc, char **argv) | ||||||
| 	return load_with_options(argc, argv, false); | 	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) | static int do_help(int argc, char **argv) | ||||||
| { | { | ||||||
| 	if (json_output) { | 	if (json_output) { | ||||||
|  | @ -1560,6 +1979,7 @@ static int do_help(int argc, char **argv) | ||||||
| 		"                         [data_out FILE [data_size_out L]] \\\n" | 		"                         [data_out FILE [data_size_out L]] \\\n" | ||||||
| 		"                         [ctx_in FILE [ctx_out FILE [ctx_size_out M]]] \\\n" | 		"                         [ctx_in FILE [ctx_out FILE [ctx_size_out M]]] \\\n" | ||||||
| 		"                         [repeat N]\n" | 		"                         [repeat N]\n" | ||||||
|  | 		"       %s %s profile PROG [duration DURATION] METRICs\n" | ||||||
| 		"       %s %s tracelog\n" | 		"       %s %s tracelog\n" | ||||||
| 		"       %s %s help\n" | 		"       %s %s help\n" | ||||||
| 		"\n" | 		"\n" | ||||||
|  | @ -1577,12 +1997,13 @@ static int do_help(int argc, char **argv) | ||||||
| 		"                 struct_ops | fentry | fexit | freplace }\n" | 		"                 struct_ops | fentry | fexit | freplace }\n" | ||||||
| 		"       ATTACH_TYPE := { msg_verdict | stream_verdict | stream_parser |\n" | 		"       ATTACH_TYPE := { msg_verdict | stream_verdict | stream_parser |\n" | ||||||
| 		"                        flow_dissector }\n" | 		"                        flow_dissector }\n" | ||||||
|  | 		"       METRIC := { cycles | instructions | l1d_loads | llc_misses }\n" | ||||||
| 		"       " HELP_SPEC_OPTIONS "\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], | ||||||
| 		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; | 	return 0; | ||||||
| } | } | ||||||
|  | @ -1599,6 +2020,7 @@ static const struct cmd cmds[] = { | ||||||
| 	{ "detach",	do_detach }, | 	{ "detach",	do_detach }, | ||||||
| 	{ "tracelog",	do_tracelog }, | 	{ "tracelog",	do_tracelog }, | ||||||
| 	{ "run",	do_run }, | 	{ "run",	do_run }, | ||||||
|  | 	{ "profile",	do_profile }, | ||||||
| 	{ 0 } | 	{ 0 } | ||||||
| }; | }; | ||||||
| 
 | 
 | ||||||
|  |  | ||||||
							
								
								
									
										119
									
								
								tools/bpf/bpftool/skeleton/profiler.bpf.c
									
									
									
									
									
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										119
									
								
								tools/bpf/bpftool/skeleton/profiler.bpf.c
									
									
									
									
									
										Normal file
									
								
							|  | @ -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
									
									
									
									
									
										Normal file
									
								
							
							
						
						
									
										47
									
								
								tools/bpf/bpftool/skeleton/profiler.h
									
									
									
									
									
										Normal file
									
								
							|  | @ -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) |   ifneq ($(V),1) | ||||||
| 	QUIET_CC       = @echo '  CC       '$@; | 	QUIET_CC       = @echo '  CC       '$@; | ||||||
| 	QUIET_CC_FPIC  = @echo '  CC FPIC  '$@; | 	QUIET_CC_FPIC  = @echo '  CC FPIC  '$@; | ||||||
|  | 	QUIET_CLANG    = @echo '  CLANG    '$@; | ||||||
| 	QUIET_AR       = @echo '  AR       '$@; | 	QUIET_AR       = @echo '  AR       '$@; | ||||||
| 	QUIET_LINK     = @echo '  LINK     '$@; | 	QUIET_LINK     = @echo '  LINK     '$@; | ||||||
| 	QUIET_MKDIR    = @echo '  MKDIR    '$@; | 	QUIET_MKDIR    = @echo '  MKDIR    '$@; | ||||||
|  |  | ||||||
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	 Song Liu
						Song Liu