#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
+#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#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>
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) {
" [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"
" 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;
}
{ "detach", do_detach },
{ "tracelog", do_tracelog },
{ "run", do_run },
+ { "profile", do_profile },
{ 0 }
};
--- /dev/null
+// 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";
projects / users / hch / dma-mapping.git / commitdiff