Commit 6af5e4cf authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
Browse files

perf bench uprobe empty: Add entry attaching an empty BPF program 



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
  #

Acked-by: default avatarIan Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andre Fredette <anfredet@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Dave Tucker <datucker@redhat.com>
Cc: Derek Barbosa <debarbos@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/20230719204910.539044-5-acme@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 54d81102

tools/perf/Makefile.perf

+1 −0
Original line number Diff line number Diff line
@@ -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 $@

tools/perf/bench/bench.h

+1 −0
Original line number Diff line number Diff line
@@ -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"

tools/perf/bench/uprobe.c

+72 −3
Original line number Diff line number Diff line
@@ -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;
@@ -77,6 +135,9 @@ static int bench_uprobe(int argc, const char **argv) 


	argc = parse_options(argc, argv, options, bench_uprobe_usage, 0);



	if (bench != BENCH_UPROBE__BASELINE && bench_uprobe__setup_bpf_skel() < 0)

		return 0;



        clock_gettime(CLOCK_REALTIME, &start);



	for (i = 0; i < loops; i++) {
@@ -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);

}

tools/perf/builtin-bench.c

+2 −1
Original line number Diff line number Diff line
@@ -106,6 +106,7 @@ static struct bench breakpoint_benchmarks[] = { 


static struct bench uprobe_benchmarks[] = {

	{ "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 },

};

tools/perf/util/bpf_skel/bench_uprobe.bpf.c

0 → 100644
+12 −0
Original line number Diff line number Diff line 
// 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";