* [RFC v2 1/2] perf: support build BPF skeletons with perf
2020-12-01 7:36 [RFC v2 0/2] Introduce perf-stat -b for BPF programs Song Liu
@ 2020-12-01 7:36 ` Song Liu
2020-12-01 20:54 ` Jiri Olsa
2020-12-01 7:36 ` [RFC v2 2/2] perf-stat: enable counting events for BPF programs Song Liu
2020-12-01 20:16 ` [RFC v2 0/2] Introduce perf-stat -b " Jiri Olsa
2 siblings, 1 reply; 8+ messages in thread
From: Song Liu @ 2020-12-01 7:36 UTC (permalink / raw)
To: linux-kernel
Cc: kernel-team, peterz, mingo, acme, mark.rutland,
alexander.shishkin, jolsa, namhyung, Song Liu
BPF programs are useful in perf to profile BPF programs. BPF skeleton is
by far the easiest way to write BPF tools. Enable building BPF skeletons
in util/bpf_skel. A dummy bpf skeleton is added. More bpf skeletons will
be added for different use cases.
Signed-off-by: Song Liu <songliubraving@fb.com>
---
tools/bpf/bpftool/Makefile | 2 ++
tools/build/Makefile.feature | 3 +-
tools/perf/Makefile.config | 9 +++++
tools/perf/Makefile.perf | 52 ++++++++++++++++++++++++++--
tools/perf/util/bpf_skel/.gitignore | 3 ++
tools/perf/util/bpf_skel/dummy.bpf.c | 19 ++++++++++
tools/scripts/Makefile.include | 1 +
7 files changed, 86 insertions(+), 3 deletions(-)
create mode 100644 tools/perf/util/bpf_skel/.gitignore
create mode 100644 tools/perf/util/bpf_skel/dummy.bpf.c
diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index f60e6ad3a1dff..a01407ec78dc5 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -120,6 +120,8 @@ endif
BPFTOOL_BOOTSTRAP := $(if $(OUTPUT),$(OUTPUT)bpftool-bootstrap,./bpftool-bootstrap)
+bootstrap: $(BPFTOOL_BOOTSTRAP)
+
BOOTSTRAP_OBJS = $(addprefix $(OUTPUT),main.o common.o json_writer.o gen.o btf.o)
OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o
diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index 97cbfb31b7625..95a58b5564218 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -70,7 +70,8 @@ FEATURE_TESTS_BASIC := \
libaio \
libzstd \
disassembler-four-args \
- file-handle
+ file-handle \
+ clang-bpf-co-re
# FEATURE_TESTS_BASIC + FEATURE_TESTS_EXTRA is the complete list
# of all feature tests
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index ce8516e4de34f..cb0cf06e0bb43 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -621,6 +621,15 @@ ifndef NO_LIBBPF
endif
endif
+ifeq ($(feature-clang-bpf-co-re), 0)
+ BUILD_BPF_SKEL := 0
+endif
+
+ifeq ($(BUILD_BPF_SKEL), 1)
+ $(call detected,CONFIG_PERF_BPF_SKEL)
+ CFLAGS += -DBUILD_BPF_SKEL
+endif
+
dwarf-post-unwind := 1
dwarf-post-unwind-text := BUG
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 7ce3f2e8b9c74..37b7ffe1db27c 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -126,6 +126,8 @@ include ../scripts/utilities.mak
#
# Define NO_LIBDEBUGINFOD if you do not want support debuginfod
#
+# Define BUILD_BPF_SKEL to enable BPF skeletons
+#
# As per kernel Makefile, avoid funny character set dependencies
unexport LC_ALL
@@ -735,7 +737,8 @@ prepare: $(OUTPUT)PERF-VERSION-FILE $(OUTPUT)common-cmds.h archheaders $(drm_ioc
$(x86_arch_prctl_code_array) \
$(rename_flags_array) \
$(arch_errno_name_array) \
- $(sync_file_range_arrays)
+ $(sync_file_range_arrays) \
+ bpf-skel
$(OUTPUT)%.o: %.c prepare FORCE
$(Q)$(MAKE) -f $(srctree)/tools/build/Makefile.build dir=$(build-dir) $@
@@ -1008,7 +1011,52 @@ config-clean:
python-clean:
$(python-clean)
-clean:: $(LIBTRACEEVENT)-clean $(LIBAPI)-clean $(LIBBPF)-clean $(LIBSUBCMD)-clean $(LIBPERF)-clean config-clean fixdep-clean python-clean
+SKEL_OUT := $(abspath util/bpf_skel)
+SKEL_TMP_OUT := $(abspath util/bpf_skel/.tmp)
+SKELETONS := $(SKEL_OUT)/dummy.skel.h
+
+ifdef BUILD_BPF_SKEL
+CLANG ?= clang
+LLVM_STRIP ?= llvm-strip
+BPFTOOL_CFLAGS := $(filter-out -D_GNU_SOURCE,$(CFLAGS))
+BPFTOOL := $(SKEL_TMP_OUT)/bpftool-bootstrap
+LIBBPF_SRC := $(abspath ../lib/bpf)
+BPFOBJ := $(SKEL_TMP_OUT)/libbpf.a
+BPF_INCLUDE := $(SKEL_TMP_OUT)
+submake_extras := feature_display=0
+
+$(SKEL_TMP_OUT):
+ $(Q)$(MKDIR) -p $@
+
+$(BPFTOOL): | $(SKEL_TMP_OUT)
+ CFLAGS= $(MAKE) $(submake_extras) -C ../bpf/bpftool \
+ OUTPUT=$(SKEL_TMP_OUT)/ bootstrap
+
+$(SKEL_TMP_OUT)/%.bpf.o: util/bpf_skel/%.bpf.c $(BPFOBJ) | $(SKEL_TMP_OUT)
+ $(call QUIET_CLANG, $@)
+ $(Q)$(CLANG) -g -O2 -target bpf -c $(filter util/bpf_skel/%.bpf.c,$^) -o $@ && \
+ $(LLVM_STRIP) -g $@
+
+$(SKEL_OUT)/%.skel.h: $(SKEL_TMP_OUT)/%.bpf.o | $(BPFTOOL)
+ $(call QUIET_GENSKEL, $@)
+ $(Q)$(BPFTOOL) gen skeleton $< > $@
+
+bpf-skel: $(SKELETONS)
+
+$(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(SKEL_TMP_OUT)
+ $(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC) \
+ OUTPUT=$(abspath $(dir $@))/ $(abspath $@)
+
+else # BUILD_BPF_SKEL
+
+bpf-skel:
+
+endif # BUILD_BPF_SKEL
+
+bpf-skel-clean:
+ $(call QUIET_CLEAN, bpf-skel) $(RM) -r $(SKEL_TMP_OUT) $(SKELETONS)
+
+clean:: $(LIBTRACEEVENT)-clean $(LIBAPI)-clean $(LIBBPF)-clean $(LIBSUBCMD)-clean $(LIBPERF)-clean config-clean fixdep-clean python-clean bpf-skel-clean
$(call QUIET_CLEAN, core-objs) $(RM) $(LIBPERF_A) $(OUTPUT)perf-archive $(OUTPUT)perf-with-kcore $(LANG_BINDINGS)
$(Q)find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete
$(Q)$(RM) $(OUTPUT).config-detected
diff --git a/tools/perf/util/bpf_skel/.gitignore b/tools/perf/util/bpf_skel/.gitignore
new file mode 100644
index 0000000000000..5263e9e6c5d83
--- /dev/null
+++ b/tools/perf/util/bpf_skel/.gitignore
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+.tmp
+*.skel.h
\ No newline at end of file
diff --git a/tools/perf/util/bpf_skel/dummy.bpf.c b/tools/perf/util/bpf_skel/dummy.bpf.c
new file mode 100644
index 0000000000000..492a43a851deb
--- /dev/null
+++ b/tools/perf/util/bpf_skel/dummy.bpf.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// Copyright (c) 2020 Facebook
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+struct {
+ __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+ __uint(key_size, sizeof(__u32));
+ __uint(value_size, sizeof(__u64));
+} counts SEC(".maps");
+
+SEC("fentry/dummy")
+int BPF_PROG(fentry_dummy)
+{
+ return 0;
+}
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";
diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include
index a7974638561ca..ed1720dc12194 100644
--- a/tools/scripts/Makefile.include
+++ b/tools/scripts/Makefile.include
@@ -126,6 +126,7 @@ ifneq ($(silent),1)
QUIET_CLEAN = @printf ' CLEAN %s\n' $1;
QUIET_INSTALL = @printf ' INSTALL %s\n' $1;
QUIET_UNINST = @printf ' UNINST %s\n' $1;
+ QUIET_GENSKEL = @printf ' GEN-SKEL %s\n' $1;
endif
endif
--
2.24.1
^ permalink raw reply related [flat|nested] 8+ messages in thread* [RFC v2 2/2] perf-stat: enable counting events for BPF programs
2020-12-01 7:36 [RFC v2 0/2] Introduce perf-stat -b for BPF programs Song Liu
2020-12-01 7:36 ` [RFC v2 1/2] perf: support build BPF skeletons with perf Song Liu
@ 2020-12-01 7:36 ` Song Liu
2020-12-01 20:16 ` [RFC v2 0/2] Introduce perf-stat -b " Jiri Olsa
2 siblings, 0 replies; 8+ messages in thread
From: Song Liu @ 2020-12-01 7:36 UTC (permalink / raw)
To: linux-kernel
Cc: kernel-team, peterz, mingo, acme, mark.rutland,
alexander.shishkin, jolsa, namhyung, Song Liu
Introduce perf-stat -b option, which counts events for BPF programs, like:
[root@localhost ~]# ~/perf stat -e ref-cycles,cycles -b 254 -I 1000
1.487903822 115,200 ref-cycles
1.487903822 86,012 cycles
2.489147029 80,560 ref-cycles
2.489147029 73,784 cycles
3.490341825 60,720 ref-cycles
3.490341825 37,797 cycles
4.491540887 37,120 ref-cycles
4.491540887 31,963 cycles
The example above counts cycles and ref-cycles of BPF program of id 254.
This is similar to bpftool-prog-profile command, but more flexible.
perf-stat -b creates per-cpu perf_event and loads fentry/fexit BPF
programs (monitor-progs) to the target BPF program (target-prog). The
monitor-progs read perf_event before and after the target-prog, and
aggregate the difference in a BPF map. Then the user space reads data
from these maps.
A new struct bpf_counter is introduced to provide common interface that
uses BPF programs/maps to count perf events.
Signed-off-by: Song Liu <songliubraving@fb.com>
---
tools/perf/Makefile.perf | 2 +-
tools/perf/builtin-stat.c | 59 ++++-
tools/perf/util/Build | 1 +
tools/perf/util/bpf_counter.c | 215 ++++++++++++++++++
tools/perf/util/bpf_counter.h | 71 ++++++
.../util/bpf_skel/bpf_prog_profiler.bpf.c | 96 ++++++++
tools/perf/util/evsel.c | 10 +
tools/perf/util/evsel.h | 5 +
tools/perf/util/target.h | 6 +
9 files changed, 456 insertions(+), 9 deletions(-)
create mode 100644 tools/perf/util/bpf_counter.c
create mode 100644 tools/perf/util/bpf_counter.h
create mode 100644 tools/perf/util/bpf_skel/bpf_prog_profiler.bpf.c
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 37b7ffe1db27c..d926f0c35ed46 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -1013,7 +1013,7 @@ python-clean:
SKEL_OUT := $(abspath util/bpf_skel)
SKEL_TMP_OUT := $(abspath util/bpf_skel/.tmp)
-SKELETONS := $(SKEL_OUT)/dummy.skel.h
+SKELETONS := $(SKEL_OUT)/dummy.skel.h $(SKEL_OUT)/bpf_prog_profiler.skel.h
ifdef BUILD_BPF_SKEL
CLANG ?= clang
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index f15b2f8aa14d8..d6df04cc24073 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -67,6 +67,7 @@
#include "util/top.h"
#include "util/affinity.h"
#include "util/pfm.h"
+#include "util/bpf_counter.h"
#include "asm/bug.h"
#include <linux/time64.h>
@@ -409,12 +410,31 @@ static int read_affinity_counters(struct timespec *rs)
return 0;
}
+static int read_bpf_map_counters(void)
+{
+ struct evsel *counter;
+ int err;
+
+ evlist__for_each_entry(evsel_list, counter) {
+ err = bpf_counter__read(counter);
+ if (err)
+ return err;
+ }
+ return 0;
+}
+
static void read_counters(struct timespec *rs)
{
struct evsel *counter;
+ int err;
- if (!stat_config.stop_read_counter && (read_affinity_counters(rs) < 0))
- return;
+ if (!stat_config.stop_read_counter) {
+ err = read_bpf_map_counters();
+ if (err == -EAGAIN)
+ err = read_affinity_counters(rs);
+ if (err < 0)
+ return;
+ }
evlist__for_each_entry(evsel_list, counter) {
if (counter->err)
@@ -496,11 +516,20 @@ static bool handle_interval(unsigned int interval, int *times)
return false;
}
-static void enable_counters(void)
+static int enable_counters(void)
{
+ struct evsel *evsel;
+ int err;
+
+ evlist__for_each_entry(evsel_list, evsel) {
+ err = bpf_counter__enable(evsel);
+ if (err)
+ return err;
+ }
+
if (stat_config.initial_delay < 0) {
pr_info(EVLIST_DISABLED_MSG);
- return;
+ return 0;
}
if (stat_config.initial_delay > 0) {
@@ -518,6 +547,7 @@ static void enable_counters(void)
if (stat_config.initial_delay > 0)
pr_info(EVLIST_ENABLED_MSG);
}
+ return 0;
}
static void disable_counters(void)
@@ -720,7 +750,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
const bool forks = (argc > 0);
bool is_pipe = STAT_RECORD ? perf_stat.data.is_pipe : false;
struct affinity affinity;
- int i, cpu;
+ int i, cpu, err;
bool second_pass = false;
if (forks) {
@@ -738,6 +768,11 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
if (affinity__setup(&affinity) < 0)
return -1;
+ evlist__for_each_entry(evsel_list, counter) {
+ if (bpf_counter__load(counter, &target))
+ return -1;
+ }
+
evlist__for_each_cpu (evsel_list, i, cpu) {
affinity__set(&affinity, cpu);
@@ -851,7 +886,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
}
if (STAT_RECORD) {
- int err, fd = perf_data__fd(&perf_stat.data);
+ int fd = perf_data__fd(&perf_stat.data);
if (is_pipe) {
err = perf_header__write_pipe(perf_data__fd(&perf_stat.data));
@@ -877,7 +912,9 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
if (forks) {
perf_evlist__start_workload(evsel_list);
- enable_counters();
+ err = enable_counters();
+ if (err)
+ return -1;
if (interval || timeout || evlist__ctlfd_initialized(evsel_list))
status = dispatch_events(forks, timeout, interval, ×);
@@ -896,7 +933,9 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
if (WIFSIGNALED(status))
psignal(WTERMSIG(status), argv[0]);
} else {
- enable_counters();
+ err = enable_counters();
+ if (err)
+ return -1;
status = dispatch_events(forks, timeout, interval, ×);
}
@@ -1087,6 +1126,10 @@ static struct option stat_options[] = {
"stat events on existing process id"),
OPT_STRING('t', "tid", &target.tid, "tid",
"stat events on existing thread id"),
+#ifdef BUILD_BPF_SKEL
+ OPT_STRING('b', "bpf-prog", &target.bpf_prog_id, "bpf-prog-id",
+ "stat events on existing bpf program id"),
+#endif
OPT_BOOLEAN('a', "all-cpus", &target.system_wide,
"system-wide collection from all CPUs"),
OPT_BOOLEAN('g', "group", &group,
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index e2563d0154eb6..188521f343470 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -135,6 +135,7 @@ perf-y += clockid.o
perf-$(CONFIG_LIBBPF) += bpf-loader.o
perf-$(CONFIG_LIBBPF) += bpf_map.o
+perf-$(CONFIG_PERF_BPF_SKEL) += bpf_counter.o
perf-$(CONFIG_BPF_PROLOGUE) += bpf-prologue.o
perf-$(CONFIG_LIBELF) += symbol-elf.o
perf-$(CONFIG_LIBELF) += probe-file.o
diff --git a/tools/perf/util/bpf_counter.c b/tools/perf/util/bpf_counter.c
new file mode 100644
index 0000000000000..25456a179af26
--- /dev/null
+++ b/tools/perf/util/bpf_counter.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/* Copyright (c) 2019 Facebook */
+
+#include <limits.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <linux/err.h>
+#include <bpf/bpf.h>
+#include <bpf/btf.h>
+#include <bpf/libbpf.h>
+
+#include "bpf_counter.h"
+#include "counts.h"
+#include "debug.h"
+#include "evsel.h"
+#include "target.h"
+
+#include "bpf_skel/bpf_prog_profiler.skel.h"
+
+static inline void *u64_to_ptr(__u64 ptr)
+{
+ return (void *)(unsigned long)ptr;
+}
+
+static char *bpf_target_prog_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)) {
+ pr_debug2("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)) {
+ pr_debug2("prog FD %d doesn't have valid btf", tgt_fd);
+ goto out;
+ }
+
+ func_info = u64_to_ptr(info_linear->info.func_info);
+ t = btf__type_by_id(btf, func_info[0].type_id);
+ if (!t) {
+ pr_debug2("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 void set_max_rlimit(void)
+{
+ struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY };
+
+ setrlimit(RLIMIT_MEMLOCK, &rinf);
+}
+
+static int bpf_program_profiler__load(struct evsel *evsel, struct target *target)
+{
+ struct bpf_prog_profiler_bpf *skel;
+ struct bpf_program *prog;
+ char *prog_name;
+ char *end_ptr;
+ u32 prog_id;
+ int prog_fd;
+ int err;
+
+ prog_id = strtoul(target->bpf_prog_id, &end_ptr, 10);
+ if (prog_id == 0 || prog_id == UINT_MAX || *end_ptr != '\0') {
+ pr_debug("Failed to parse bpf prog id %s\n", target->bpf_prog_id);
+ return -1;
+ }
+ prog_fd = bpf_prog_get_fd_by_id(prog_id);
+ if (prog_fd < 0) {
+ pr_debug("Failed to open fd for bpf prog %u\n", prog_id);
+ return -1;
+ }
+
+ skel = bpf_prog_profiler_bpf__open();
+ if (!skel) {
+ pr_debug("Failed to load bpf skeleton\n");
+ return -1;
+ }
+ skel->rodata->num_cpu = evsel__nr_cpus(evsel);
+
+ bpf_map__resize(skel->maps.events, evsel__nr_cpus(evsel));
+ bpf_map__resize(skel->maps.fentry_readings, 1);
+ bpf_map__resize(skel->maps.accum_readings, 1);
+
+ prog_name = bpf_target_prog_name(prog_fd);
+
+ bpf_object__for_each_program(prog, skel->obj) {
+ err = bpf_program__set_attach_target(prog, prog_fd, prog_name);
+ if (err)
+ pr_debug("bpf_program__set_attach_target failed\n");
+ }
+ set_max_rlimit();
+ err = bpf_prog_profiler_bpf__load(skel);
+ if (err)
+ pr_debug("bpf_prog_profiler_bpf__load failed\n");
+
+ evsel->bpf_counter.skel = skel;
+ return 0;
+}
+
+static int bpf_program_profiler__enable(struct evsel *evsel)
+{
+ struct bpf_prog_profiler_bpf *skel = evsel->bpf_counter.skel;
+
+ return bpf_prog_profiler_bpf__attach(skel);
+}
+
+static int bpf_program_profiler__read(struct evsel *evsel)
+{
+ struct bpf_prog_profiler_bpf *skel = evsel->bpf_counter.skel;
+ int num_cpu = evsel__nr_cpus(evsel);
+ struct bpf_perf_event_value values[num_cpu];
+ int reading_map_fd;
+ __u32 key = 0;
+ int err, cpu;
+
+ if (!skel)
+ return -EAGAIN;
+
+ reading_map_fd = bpf_map__fd(skel->maps.accum_readings);
+
+ err = bpf_map_lookup_elem(reading_map_fd, &key, values);
+ if (err) {
+ fprintf(stderr, "failed to read value\n");
+ return err;
+ }
+
+ for (cpu = 0; cpu < num_cpu; cpu++) {
+ perf_counts(evsel->counts, cpu, 0)->val = values[cpu].counter;
+ perf_counts(evsel->counts, cpu, 0)->ena = values[cpu].enabled;
+ perf_counts(evsel->counts, cpu, 0)->run = values[cpu].running;
+ }
+
+ return 0;
+}
+
+static int bpf_program_profiler__destroy(struct evsel *evsel)
+{
+ struct bpf_prog_profiler_bpf *skel = evsel->bpf_counter.skel;
+
+ bpf_prog_profiler_bpf__destroy(skel);
+ return 0;
+}
+
+static int bpf_program_profiler__install_pe(struct evsel *evsel, int cpu,
+ int fd)
+{
+ struct bpf_prog_profiler_bpf *skel = evsel->bpf_counter.skel;
+
+ return bpf_map_update_elem(bpf_map__fd(skel->maps.events),
+ &cpu, &fd, BPF_ANY);
+}
+
+struct bpf_counter_ops bpf_program_profiler_ops = {
+ .load = bpf_program_profiler__load,
+ .enable = bpf_program_profiler__enable,
+ .read = bpf_program_profiler__read,
+ .destroy = bpf_program_profiler__destroy,
+ .install_pe = bpf_program_profiler__install_pe,
+};
+
+int bpf_counter__install_pe(struct evsel *evsel, int cpu, int fd)
+{
+ if (!evsel->bpf_counter.skel)
+ return 0;
+ return evsel->bpf_counter.ops->install_pe(evsel, cpu, fd);
+}
+
+int bpf_counter__load(struct evsel *evsel, struct target *target)
+{
+ if (target__has_bpf(target))
+ evsel->bpf_counter.ops = &bpf_program_profiler_ops;
+
+ if (evsel->bpf_counter.ops)
+ return evsel->bpf_counter.ops->load(evsel, target);
+ return 0;
+}
+
+int bpf_counter__enable(struct evsel *evsel)
+{
+ if (!evsel->bpf_counter.skel)
+ return 0;
+ return evsel->bpf_counter.ops->enable(evsel);
+}
+
+int bpf_counter__read(struct evsel *evsel)
+{
+ if (!evsel->bpf_counter.skel)
+ return -EAGAIN;
+ return evsel->bpf_counter.ops->read(evsel);
+}
+
+int bpf_counter__destroy(struct evsel *evsel)
+{
+ if (!evsel->bpf_counter.skel)
+ return 0;
+ evsel->bpf_counter.ops->destroy(evsel);
+ evsel->bpf_counter.skel = NULL;
+ evsel->bpf_counter.ops = NULL;
+ return 0;
+}
diff --git a/tools/perf/util/bpf_counter.h b/tools/perf/util/bpf_counter.h
new file mode 100644
index 0000000000000..9f8f9bd3ec6e2
--- /dev/null
+++ b/tools/perf/util/bpf_counter.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PERF_BPF_COUNTER_H
+#define __PERF_BPF_COUNTER_H 1
+
+struct evsel;
+struct target;
+struct bpf_counter;
+
+typedef int (*bpf_counter_evsel_op)(struct evsel *evsel);
+typedef int (*bpf_counter_evsel_target_op)(struct evsel *evsel,
+ struct target *target);
+typedef int (*bpf_counter_evsel_install_pe_op)(struct evsel *evsel,
+ int cpu,
+ int fd);
+
+struct bpf_counter_ops {
+ bpf_counter_evsel_target_op load;
+ bpf_counter_evsel_op enable;
+ bpf_counter_evsel_op read;
+ bpf_counter_evsel_op destroy;
+ bpf_counter_evsel_install_pe_op install_pe;
+};
+
+struct bpf_counter {
+ void *skel;
+ struct bpf_counter_ops *ops;
+};
+
+#ifdef BUILD_BPF_SKEL
+
+int bpf_counter__load(struct evsel *evsel, struct target *target);
+int bpf_counter__enable(struct evsel *evsel);
+int bpf_counter__read(struct evsel *evsel);
+int bpf_counter__destroy(struct evsel *evsel);
+int bpf_counter__install_pe(struct evsel *evsel, int cpu, int fd);
+
+#else
+
+#include<linux/err.h>
+
+static inline int bpf_counter__load(struct evsel *evsel __maybe_unused,
+ struct target *target __maybe_unused)
+{
+ return 0;
+}
+
+static inline int bpf_counter__enable(struct evsel *evsel __maybe_unused)
+{
+ return 0;
+}
+
+static inline int bpf_counter__read(struct evsel *evsel __maybe_unused)
+{
+ return -EAGAIN;
+}
+
+static inline int bpf_counter__destroy(struct evsel *evsel __maybe_unused)
+{
+ return 0;
+}
+
+static inline int bpf_counter__install_pe(struct evsel *evsel __maybe_unused,
+ int cpu __maybe_unused,
+ int fd __maybe_unused)
+{
+ return 0;
+}
+
+#endif /* BUILD_BPF_SKEL */
+
+#endif /* __PERF_BPF_COUNTER_H */
diff --git a/tools/perf/util/bpf_skel/bpf_prog_profiler.bpf.c b/tools/perf/util/bpf_skel/bpf_prog_profiler.bpf.c
new file mode 100644
index 0000000000000..cdde2218af86a
--- /dev/null
+++ b/tools/perf/util/bpf_skel/bpf_prog_profiler.bpf.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// Copyright (c) 2020 Facebook
+#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));
+ __uint(max_entries, 1);
+} 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));
+ __uint(max_entries, 1);
+} accum_readings SEC(".maps");
+
+const volatile __u32 num_cpu = 1;
+
+SEC("fentry/XXX")
+int BPF_PROG(fentry_XXX)
+{
+ __u32 key = bpf_get_smp_processor_id();
+ struct bpf_perf_event_value reading;
+ struct bpf_perf_event_value *ptr;
+ __u32 zero = 0;
+ long err;
+
+ /* look up before reading, to reduce error */
+ ptr = bpf_map_lookup_elem(&fentry_readings, &zero);
+ if (!ptr)
+ return 0;
+
+ err = bpf_perf_event_read_value(&events, key, &reading,
+ sizeof(reading));
+ if (err)
+ return 0;
+
+ *ptr = reading;
+ return 0;
+}
+
+static inline void
+fexit_update_maps(struct bpf_perf_event_value *after)
+{
+ struct bpf_perf_event_value *before, diff, *accum;
+ __u32 zero = 0;
+
+ before = bpf_map_lookup_elem(&fentry_readings, &zero);
+ /* 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, &zero);
+ 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 reading;
+ __u32 cpu = bpf_get_smp_processor_id();
+ __u32 one = 1, zero = 0;
+ int err;
+
+ /* read all events before updating the maps, to reduce error */
+ err = bpf_perf_event_read_value(&events, cpu, &reading, sizeof(reading));
+ if (err)
+ return 0;
+
+ fexit_update_maps(&reading);
+ return 0;
+}
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 1cad6051d8b08..6376b8db58e09 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -25,6 +25,7 @@
#include <stdlib.h>
#include <perf/evsel.h>
#include "asm/bug.h"
+#include "bpf_counter.h"
#include "callchain.h"
#include "cgroup.h"
#include "counts.h"
@@ -51,6 +52,10 @@
#include <internal/lib.h>
#include <linux/ctype.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include <bpf/btf.h>
+#include "rlimit.h"
struct perf_missing_features perf_missing_features;
@@ -1365,6 +1370,7 @@ void evsel__exit(struct evsel *evsel)
{
assert(list_empty(&evsel->core.node));
assert(evsel->evlist == NULL);
+ bpf_counter__destroy(evsel);
evsel__free_counts(evsel);
perf_evsel__free_fd(&evsel->core);
perf_evsel__free_id(&evsel->core);
@@ -1770,6 +1776,8 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
evsel->core.attr.sample_id_all = 0;
display_attr(&evsel->core.attr);
+ if (evsel->bpf_counter.skel)
+ evsel->core.attr.inherit = 0;
for (cpu = start_cpu; cpu < end_cpu; cpu++) {
@@ -1788,6 +1796,8 @@ static int evsel__open_cpu(struct evsel *evsel, struct perf_cpu_map *cpus,
FD(evsel, cpu, thread) = fd;
+ bpf_counter__install_pe(evsel, cpu, fd);
+
if (unlikely(test_attr__enabled)) {
test_attr__open(&evsel->core.attr, pid, cpus->map[cpu],
fd, group_fd, flags);
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 79a860d8e3eef..3a44f7b25726c 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -10,6 +10,7 @@
#include <internal/evsel.h>
#include <perf/evsel.h>
#include "symbol_conf.h"
+#include "bpf_counter.h"
#include <internal/cpumap.h>
struct bpf_object;
@@ -17,6 +18,8 @@ struct cgroup;
struct perf_counts;
struct perf_stat_evsel;
union perf_event;
+struct bpf_counter;
+struct target;
typedef int (evsel__sb_cb_t)(union perf_event *event, void *data);
@@ -127,6 +130,7 @@ struct evsel {
* See also evsel__has_callchain().
*/
__u64 synth_sample_type;
+ struct bpf_counter bpf_counter;
};
struct perf_missing_features {
@@ -423,4 +427,5 @@ static inline bool evsel__is_dummy_event(struct evsel *evsel)
struct perf_env *evsel__env(struct evsel *evsel);
int evsel__store_ids(struct evsel *evsel, struct evlist *evlist);
+
#endif /* __PERF_EVSEL_H */
diff --git a/tools/perf/util/target.h b/tools/perf/util/target.h
index 6ef01a83b24e9..cdaa7510f918b 100644
--- a/tools/perf/util/target.h
+++ b/tools/perf/util/target.h
@@ -10,6 +10,7 @@ struct target {
const char *tid;
const char *cpu_list;
const char *uid_str;
+ const char *bpf_prog_id;
uid_t uid;
bool system_wide;
bool uses_mmap;
@@ -59,6 +60,11 @@ static inline bool target__has_cpu(struct target *target)
return target->system_wide || target->cpu_list;
}
+static inline bool target__has_bpf(struct target *target)
+{
+ return target->bpf_prog_id;
+}
+
static inline bool target__none(struct target *target)
{
return !target__has_task(target) && !target__has_cpu(target);
--
2.24.1
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