[PATCH 4/5] perf bench uprobe empty: Add entry attaching an empty BPF program
From: Arnaldo Carvalho de Melo
Date: Wed Jul 19 2023 - 16:49:54 EST
From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Using libbpf and a BPF skel:
# perf bench uprobe all
# Running uprobe/baseline benchmark...
# Executed 1,000 usleep(1000) calls
Total time: 1,055,618 usecs
1,055.618 usecs/op
# Running uprobe/empty benchmark...
# Executed 1,000 usleep(1000) calls
Total time: 1,057,146 usecs +1,528 to baseline
1,057.146 usecs/op
#
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Andre Fredette <anfredet@xxxxxxxxxx>
Cc: Clark Williams <williams@xxxxxxxxxx>
Cc: Dave Tucker <datucker@xxxxxxxxxx>
Cc: Derek Barbosa <debarbos@xxxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Makefile.perf | 1 +
tools/perf/bench/bench.h | 1 +
tools/perf/bench/uprobe.c | 75 ++++++++++++++++++++-
tools/perf/builtin-bench.c | 3 +-
tools/perf/util/bpf_skel/bench_uprobe.bpf.c | 12 ++++
5 files changed, 88 insertions(+), 4 deletions(-)
create mode 100644 tools/perf/util/bpf_skel/bench_uprobe.bpf.c
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 097316ef38e6a80f..a44d16ec11ee5490 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -1057,6 +1057,7 @@ SKELETONS += $(SKEL_OUT)/bperf_leader.skel.h $(SKEL_OUT)/bperf_follower.skel.h
SKELETONS += $(SKEL_OUT)/bperf_cgroup.skel.h $(SKEL_OUT)/func_latency.skel.h
SKELETONS += $(SKEL_OUT)/off_cpu.skel.h $(SKEL_OUT)/lock_contention.skel.h
SKELETONS += $(SKEL_OUT)/kwork_trace.skel.h $(SKEL_OUT)/sample_filter.skel.h
+SKELETONS += $(SKEL_OUT)/bench_uprobe.skel.h
$(SKEL_TMP_OUT) $(LIBAPI_OUTPUT) $(LIBBPF_OUTPUT) $(LIBPERF_OUTPUT) $(LIBSUBCMD_OUTPUT) $(LIBSYMBOL_OUTPUT):
$(Q)$(MKDIR) -p $@
diff --git a/tools/perf/bench/bench.h b/tools/perf/bench/bench.h
index 201311f75c964df2..daf4850b441cf91c 100644
--- a/tools/perf/bench/bench.h
+++ b/tools/perf/bench/bench.h
@@ -43,6 +43,7 @@ int bench_evlist_open_close(int argc, const char **argv);
int bench_breakpoint_thread(int argc, const char **argv);
int bench_breakpoint_enable(int argc, const char **argv);
int bench_uprobe_baseline(int argc, const char **argv);
+int bench_uprobe_empty(int argc, const char **argv);
int bench_pmu_scan(int argc, const char **argv);
#define BENCH_FORMAT_DEFAULT_STR "default"
diff --git a/tools/perf/bench/uprobe.c b/tools/perf/bench/uprobe.c
index a90e09f791c540a9..dfb90038a4f7a06a 100644
--- a/tools/perf/bench/uprobe.c
+++ b/tools/perf/bench/uprobe.c
@@ -24,6 +24,11 @@
#define LOOPS_DEFAULT 1000
static int loops = LOOPS_DEFAULT;
+enum bench_uprobe {
+ BENCH_UPROBE__BASELINE,
+ BENCH_UPROBE__EMPTY,
+};
+
static const struct option options[] = {
OPT_INTEGER('l', "loop", &loops, "Specify number of loops"),
OPT_END()
@@ -34,6 +39,59 @@ static const char * const bench_uprobe_usage[] = {
NULL
};
+#ifdef HAVE_BPF_SKEL
+#include "bpf_skel/bench_uprobe.skel.h"
+
+struct bench_uprobe_bpf *skel;
+
+static int bench_uprobe__setup_bpf_skel(void)
+{
+ DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
+ int err;
+
+ /* Load and verify BPF application */
+ skel = bench_uprobe_bpf__open();
+ if (!skel) {
+ fprintf(stderr, "Failed to open and load uprobes bench BPF skeleton\n");
+ return -1;
+ }
+
+ err = bench_uprobe_bpf__load(skel);
+ if (err) {
+ fprintf(stderr, "Failed to load and verify BPF skeleton\n");
+ goto cleanup;
+ }
+
+ uprobe_opts.func_name = "usleep";
+ skel->links.empty = bpf_program__attach_uprobe_opts(/*prog=*/skel->progs.empty,
+ /*pid=*/-1,
+ /*binary_path=*/"/lib64/libc.so.6",
+ /*func_offset=*/0,
+ /*opts=*/&uprobe_opts);
+ if (!skel->links.empty) {
+ err = -errno;
+ fprintf(stderr, "Failed to attach bench uprobe: %s\n", strerror(errno));
+ goto cleanup;
+ }
+
+ return err;
+cleanup:
+ bench_uprobe_bpf__destroy(skel);
+ return err;
+}
+
+static void bench_uprobe__teardown_bpf_skel(void)
+{
+ if (skel) {
+ bench_uprobe_bpf__destroy(skel);
+ skel = NULL;
+ }
+}
+#else
+static int bench_uprobe__setup_bpf_skel(void) { return 0; }
+static void bench_uprobe__teardown_bpf_skel(void) {};
+#endif
+
static int bench_uprobe_format__default_fprintf(const char *name, const char *unit, u64 diff, FILE *fp)
{
static u64 baseline, previous;
@@ -68,7 +126,7 @@ static int bench_uprobe_format__default_fprintf(const char *name, const char *un
return printed + 1;
}
-static int bench_uprobe(int argc, const char **argv)
+static int bench_uprobe(int argc, const char **argv, enum bench_uprobe bench)
{
const char *name = "usleep(1000)", *unit = "usec";
struct timespec start, end;
@@ -77,7 +135,10 @@ static int bench_uprobe(int argc, const char **argv)
argc = parse_options(argc, argv, options, bench_uprobe_usage, 0);
- clock_gettime(CLOCK_REALTIME, &start);
+ if (bench != BENCH_UPROBE__BASELINE && bench_uprobe__setup_bpf_skel() < 0)
+ return 0;
+
+ clock_gettime(CLOCK_REALTIME, &start);
for (i = 0; i < loops; i++) {
usleep(USEC_PER_MSEC);
@@ -103,10 +164,18 @@ static int bench_uprobe(int argc, const char **argv)
exit(1);
}
+ if (bench != BENCH_UPROBE__BASELINE)
+ bench_uprobe__teardown_bpf_skel();
+
return 0;
}
int bench_uprobe_baseline(int argc, const char **argv)
{
- return bench_uprobe(argc, argv);
+ return bench_uprobe(argc, argv, BENCH_UPROBE__BASELINE);
+}
+
+int bench_uprobe_empty(int argc, const char **argv)
+{
+ return bench_uprobe(argc, argv, BENCH_UPROBE__EMPTY);
}
diff --git a/tools/perf/builtin-bench.c b/tools/perf/builtin-bench.c
index 09637aee83413e63..1021680bbc6d4298 100644
--- a/tools/perf/builtin-bench.c
+++ b/tools/perf/builtin-bench.c
@@ -105,7 +105,8 @@ static struct bench breakpoint_benchmarks[] = {
};
static struct bench uprobe_benchmarks[] = {
- { "baseline", "Baseline libc usleep(1000) call", bench_uprobe_baseline, },
+ { "baseline", "Baseline libc usleep(1000) call", bench_uprobe_baseline, },
+ { "empty", "Attach empty BPF prog to uprobe on usleep, system wide", bench_uprobe_empty, },
{ NULL, NULL, NULL },
};
diff --git a/tools/perf/util/bpf_skel/bench_uprobe.bpf.c b/tools/perf/util/bpf_skel/bench_uprobe.bpf.c
new file mode 100644
index 0000000000000000..1365dcc5dddff546
--- /dev/null
+++ b/tools/perf/util/bpf_skel/bench_uprobe.bpf.c
@@ -0,0 +1,12 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+// Copyright (c) 2023 Red Hat
+#include "vmlinux.h"
+#include <bpf/bpf_tracing.h>
+
+SEC("uprobe")
+int BPF_UPROBE(empty)
+{
+ return 0;
+}
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";
--
2.41.0