perf bench uprobe trace_printk: Add entry attaching an BPF program that does a trace_printk

  [root@five ~]# perf bench uprobe all
  # Running uprobe/baseline benchmark...
  # Executed 1,000 usleep(1000) calls
       Total time: 1,053,963 usecs

   1,053.963 usecs/op

  # Running uprobe/empty benchmark...
  # Executed 1,000 usleep(1000) calls
       Total time: 1,056,293 usecs +2,330 to baseline

   1,056.293 usecs/op 2.330 usecs/op to baseline

  # Running uprobe/trace_printk benchmark...
  # Executed 1,000 usleep(1000) calls
       Total time: 1,056,977 usecs +3,014 to baseline +684 to previous

   1,056.977 usecs/op 3.014 usecs/op to baseline 0.684 usecs/op to previous

  [root@five ~]#
Acked-by: Ian 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/20230719204910.539044-6-acme@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/bench/bench.h

@@ -44,6 +44,7 @@ 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_uprobe_trace_printk(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

@@ -11,6 +11,7 @@
 #include <subcmd/parse-options.h>
 #include "../builtin.h"
 #include "bench.h"
+#include <linux/compiler.h>
 #include <linux/time64.h>
 
 #include <inttypes.h>
@@ -27,6 +28,7 @@ static int loops = LOOPS_DEFAULT;
 enum bench_uprobe {
         BENCH_UPROBE__BASELINE,
         BENCH_UPROBE__EMPTY,
+        BENCH_UPROBE__TRACE_PRINTK,
 };
 
 static const struct option options[] = {
@@ -42,9 +44,21 @@ static const char * const bench_uprobe_usage[] = {
 #ifdef HAVE_BPF_SKEL
 #include "bpf_skel/bench_uprobe.skel.h"
 
+#define bench_uprobe__attach_uprobe(prog) \
+	skel->links.prog = bpf_program__attach_uprobe_opts(/*prog=*/skel->progs.prog, \
+							   /*pid=*/-1, \
+							   /*binary_path=*/"/lib64/libc.so.6", \
+							   /*func_offset=*/0, \
+							   /*opts=*/&uprobe_opts); \
+	if (!skel->links.prog) { \
+		err = -errno; \
+		fprintf(stderr, "Failed to attach bench uprobe \"%s\": %s\n", #prog, strerror(errno)); \
+		goto cleanup; \
+	}
+
 struct bench_uprobe_bpf *skel;
 
-static int bench_uprobe__setup_bpf_skel(void)
+static int bench_uprobe__setup_bpf_skel(enum bench_uprobe bench)
 {
 	DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
 	int err;
@@ -63,14 +77,12 @@ static int bench_uprobe__setup_bpf_skel(void)
 	}
 
 	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));
+	switch (bench) {
+	case BENCH_UPROBE__BASELINE:							break;
+	case BENCH_UPROBE__EMPTY:	 bench_uprobe__attach_uprobe(empty);		break;
+	case BENCH_UPROBE__TRACE_PRINTK: bench_uprobe__attach_uprobe(trace_printk);	break;
+	default:
+		fprintf(stderr, "Invalid bench: %d\n", bench);
 		goto cleanup;
 	}
 
@@ -88,7 +100,7 @@ static void bench_uprobe__teardown_bpf_skel(void)
 	}
 }
 #else
-static int bench_uprobe__setup_bpf_skel(void) { return 0; }
+static int bench_uprobe__setup_bpf_skel(enum bench_uprobe bench __maybe_unused) { return 0; }
 static void bench_uprobe__teardown_bpf_skel(void) {};
 #endif
 
@@ -135,7 +147,7 @@ static int bench_uprobe(int argc, const char **argv, enum bench_uprobe bench)
 
 	argc = parse_options(argc, argv, options, bench_uprobe_usage, 0);
 
-	if (bench != BENCH_UPROBE__BASELINE && bench_uprobe__setup_bpf_skel() < 0)
+	if (bench != BENCH_UPROBE__BASELINE && bench_uprobe__setup_bpf_skel(bench) < 0)
 		return 0;
 
         clock_gettime(CLOCK_REALTIME, &start);
@@ -179,3 +191,8 @@ int bench_uprobe_empty(int argc, const char **argv)
 {
 	return bench_uprobe(argc, argv, BENCH_UPROBE__EMPTY);
 }
+
+int bench_uprobe_trace_printk(int argc, const char **argv)
+{
+	return bench_uprobe(argc, argv, BENCH_UPROBE__TRACE_PRINTK);
+}

tools/perf/builtin-bench.c

@@ -107,6 +107,7 @@ 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,	},
+	{ "trace_printk", "Attach trace_printk BPF prog to uprobe on usleep syswide",	bench_uprobe_trace_printk,	},
 	{ NULL,	NULL, NULL },
 };
 

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

@@ -3,10 +3,21 @@
 #include "vmlinux.h"
 #include <bpf/bpf_tracing.h>
 
+unsigned int nr_uprobes;
+
 SEC("uprobe")
 int BPF_UPROBE(empty)
 {
        return 0;
 }
 
+SEC("uprobe")
+int BPF_UPROBE(trace_printk)
+{
+	char fmt[] = "perf bench uprobe %u";
+
+	bpf_trace_printk(fmt, sizeof(fmt), ++nr_uprobes);
+	return 0;
+}
+
 char LICENSE[] SEC("license") = "Dual BSD/GPL";