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
alistair/sensors
Song Liu
Daniel Borkmann
parent
7b4b73bc8a
commit
47c09d6a9f
|
|
@ -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 }
|
||||
};
|
||||
|
||||
|
|
|
|||
|
|
@ -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";
|
||||
|
|
@ -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 '$@;
|
||||
|
|
|
|||
Loading…
Reference in New Issue