[PATCH 87/91] perf bench: Add kallsyms parsing

Arnaldo Carvalho de Melo
2020-05-06T15:27:35Z

From: Ian Rogers <irogers@google.com>

Add a benchmark for kallsyms parsing. Example output:

Running 'internals/kallsyms-parse' benchmark:
Average kallsyms__parse took: 103.971 ms (+- 0.121 ms)

Committer testing:

Test Machine: AMD Ryzen 5 3600X 6-Core Processor

[root@five ~]# perf bench internals kallsyms-parse
# Running 'internals/kallsyms-parse' benchmark:
Average kallsyms__parse took: 79.692 ms (+- 0.101 ms)
[root@five ~]# perf stat -r5 perf bench internals kallsyms-parse
# Running 'internals/kallsyms-parse' benchmark:
Average kallsyms__parse took: 80.563 ms (+- 0.079 ms)
# Running 'internals/kallsyms-parse' benchmark:
Average kallsyms__parse took: 81.046 ms (+- 0.155 ms)
# Running 'internals/kallsyms-parse' benchmark:
Average kallsyms__parse took: 80.874 ms (+- 0.104 ms)
# Running 'internals/kallsyms-parse' benchmark:
Average kallsyms__parse took: 81.173 ms (+- 0.133 ms)
# Running 'internals/kallsyms-parse' benchmark:
Average kallsyms__parse took: 81.169 ms (+- 0.074 ms)

Performance counter stats for 'perf bench internals kallsyms-parse' (5 runs):

8,093.54 msec task-clock # 0.999 CPUs utilized ( +- 0.14% )
3,165 context-switches # 0.391 K/sec ( +- 0.18% )
10 cpu-migrations # 0.001 K/sec ( +- 23.13% )
744 page-faults # 0.092 K/sec ( +- 0.21% )
34,551,564,954 cycles # 4.269 GHz ( +- 0.05% ) (83.33%)
1,160,584,308 stalled-cycles-frontend # 3.36% frontend cycles idle ( +- 1.60% ) (83.33%)
14,974,323,985 stalled-cycles-backend # 43.34% backend cycles idle ( +- 0.24% ) (83.33%)
58,712,905,705 instructions # 1.70 insn per cycle
# 0.26 stalled cycles per insn ( +- 0.01% ) (83.34%)
14,136,433,778 branches # 1746.632 M/sec ( +- 0.01% ) (83.33%)
141,943,217 branch-misses # 1.00% of all branches ( +- 0.04% ) (83.33%)

8.1040 +- 0.0115 seconds time elapsed ( +- 0.14% )

[root@five ~]#

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lore.kernel.org/lkml/20200501221315.54715-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/bench/Build | 1 +
tools/perf/bench/bench.h | 1 +
tools/perf/bench/kallsyms-parse.c | 75 +++++++++++++++++++++++++++++++
tools/perf/builtin-bench.c | 1 +
4 files changed, 78 insertions(+)
create mode 100644 tools/perf/bench/kallsyms-parse.c

diff --git a/tools/perf/bench/Build b/tools/perf/bench/Build
index 042827385c87..768e408757a0 100644
--- a/tools/perf/bench/Build
+++ b/tools/perf/bench/Build
@@ -9,6 +9,7 @@ perf-y += futex-lock-pi.o
perf-y += epoll-wait.o
perf-y += epoll-ctl.o
perf-y += synthesize.o
+perf-y += kallsyms-parse.o

perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-lib.o
perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-asm.o
diff --git a/tools/perf/bench/bench.h b/tools/perf/bench/bench.h
index 4d669c803237..61cae4966cae 100644
--- a/tools/perf/bench/bench.h
+++ b/tools/perf/bench/bench.h
@@ -44,6 +44,7 @@ int bench_futex_lock_pi(int argc, const char **argv);
int bench_epoll_wait(int argc, const char **argv);
int bench_epoll_ctl(int argc, const char **argv);
int bench_synthesize(int argc, const char **argv);
+int bench_kallsyms_parse(int argc, const char **argv);

#define BENCH_FORMAT_DEFAULT_STR "default"
#define BENCH_FORMAT_DEFAULT 0
diff --git a/tools/perf/bench/kallsyms-parse.c b/tools/perf/bench/kallsyms-parse.c
new file mode 100644
index 000000000000..2b0d0f980ae9
--- /dev/null
+++ b/tools/perf/bench/kallsyms-parse.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Benchmark of /proc/kallsyms parsing.
+ *
+ * Copyright 2020 Google LLC.
+ */
+#include <stdlib.h>
+#include "bench.h"
+#include "../util/stat.h"
+#include <linux/time64.h>
+#include <subcmd/parse-options.h>
+#include <symbol/kallsyms.h>
+
+static unsigned int iterations = 100;
+
+static const struct option options[] = {
+ OPT_UINTEGER('i', "iterations", &iterations,
+ "Number of iterations used to compute average"),
+ OPT_END()
+};
+
+static const char *const bench_usage[] = {
+ "perf bench internals kallsyms-parse <options>",
+ NULL
+};
+
+static int bench_process_symbol(void *arg __maybe_unused,
+ const char *name __maybe_unused,
+ char type __maybe_unused,
+ u64 start __maybe_unused)
+{
+ return 0;
+}
+
+static int do_kallsyms_parse(void)
+{
+ struct timeval start, end, diff;
+ u64 runtime_us;
+ unsigned int i;
+ double time_average, time_stddev;
+ int err;
+ struct stats time_stats;
+
+ init_stats(&time_stats);
+
+ for (i = 0; i < iterations; i++) {
+ gettimeofday(&start, NULL);
+ err = kallsyms__parse("/proc/kallsyms", NULL,
+ bench_process_symbol);
+ if (err)
+ return err;
+
+ gettimeofday(&end, NULL);
+ timersub(&end, &start, &diff);
+ runtime_us = diff.tv_sec * USEC_PER_SEC + diff.tv_usec;
+ update_stats(&time_stats, runtime_us);
+ }
+
+ time_average = avg_stats(&time_stats) / USEC_PER_MSEC;
+ time_stddev = stddev_stats(&time_stats) / USEC_PER_MSEC;
+ printf(" Average kallsyms__parse took: %.3f ms (+- %.3f ms)\n",
+ time_average, time_stddev);
+ return 0;
+}
+
+int bench_kallsyms_parse(int argc, const char **argv)
+{
+ argc = parse_options(argc, argv, options, bench_usage, 0);
+ if (argc) {
+ usage_with_options(bench_usage, options);
+ exit(EXIT_FAILURE);
+ }
+
+ return do_kallsyms_parse();
+}
diff --git a/tools/perf/builtin-bench.c b/tools/perf/builtin-bench.c
index 11c79a8d85d6..083273209c88 100644
--- a/tools/perf/builtin-bench.c
+++ b/tools/perf/builtin-bench.c
@@ -78,6 +78,7 @@ static struct bench epoll_benchmarks[] = {

static struct bench internals_benchmarks[] = {
{ "synthesize", "Benchmark perf event synthesis", bench_synthesize },
+ { "kallsyms-parse", "Benchmark kallsyms parsing", bench_kallsyms_parse },
{ NULL, NULL, NULL }
};

--
2.21.1