Re: [PATCH] tools/perf-bench: Add basic syscall benchmark
From: Davidlohr Bueso
Date: Fri Mar 08 2019 - 13:17:58 EST
On Thu, 07 Mar 2019, Arnaldo Carvalho de Melo wrote:
You forgot to update tools/perf/Documentation/perf-bench.txt, and please
take a look at tools/perf/util/pmu.c convert_scale() to see how to save
the current locale, set the one you want, then restore the previous one,
so that at the end of this benchmark the environment is back to where it
was.
Here's an updated version with the corresponding docs, but I removed the
setlocale() - doesn't seem worth it; I hope Mel has no strong objection.
Thanks.
-------8<----------------------------------------------------------
[PATCH v2] tools/perf-bench: Add basic syscall benchmark
The usefulness of having a standard way of testing syscall performance
has come up from time to time[0]. Furthermore, some of our testing
machinery (such as 'mmtests') already makes use of a simplified version
of the microbenchmark. This patch mainly takes the same idea to measure
syscall throughput compatible with 'perf-bench' via getppid(2), yet
without any of the additional template stuff from Ingo's version (based
on numa.c). The code is identical to what mmtests uses.
[0] https://lore.kernel.org/lkml/20160201074156.GA27156@xxxxxxxxx/
Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx>
---
tools/perf/Documentation/perf-bench.txt | 11 +++++
tools/perf/bench/Build | 1 +
tools/perf/bench/bench.h | 1 +
tools/perf/bench/syscall.c | 78 +++++++++++++++++++++++++++++++++
tools/perf/builtin-bench.c | 8 ++++
5 files changed, 99 insertions(+)
create mode 100644 tools/perf/bench/syscall.c
diff --git a/tools/perf/Documentation/perf-bench.txt b/tools/perf/Documentation/perf-bench.txt
index 0921a3c67381..8093cafc530a 100644
--- a/tools/perf/Documentation/perf-bench.txt
+++ b/tools/perf/Documentation/perf-bench.txt
@@ -49,6 +49,9 @@ SUBSYSTEM
'sched'::
Scheduler and IPC mechanisms.
+'syscall'::
+ System call performance (throughput).
+
'mem'::
Memory access performance.
@@ -134,6 +137,14 @@ Example of *pipe*
59004 ops/sec
---------------------
+SUITES FOR 'syscall'
+~~~~~~~~~~~~~~~~~~
+*basic*::
+Suite for evaluating performance of core system call throughput (both usecs/op and ops/sec metrics).
+This uses a single thread simply doing getppid(2), which is a simple syscall where the result is not
+cached by glibc.
+
+
SUITES FOR 'mem'
~~~~~~~~~~~~~~~~
*memcpy*::
diff --git a/tools/perf/bench/Build b/tools/perf/bench/Build
index e4e321b6f883..839f9b790587 100644
--- a/tools/perf/bench/Build
+++ b/tools/perf/bench/Build
@@ -1,5 +1,6 @@
perf-y += sched-messaging.o
perf-y += sched-pipe.o
+perf-y += syscall.o
perf-y += mem-functions.o
perf-y += futex-hash.o
perf-y += futex-wake.o
diff --git a/tools/perf/bench/bench.h b/tools/perf/bench/bench.h
index fddb3ced9db6..31ad3283d41b 100644
--- a/tools/perf/bench/bench.h
+++ b/tools/perf/bench/bench.h
@@ -29,6 +29,7 @@
int bench_numa(int argc, const char **argv);
int bench_sched_messaging(int argc, const char **argv);
int bench_sched_pipe(int argc, const char **argv);
+int bench_syscall_basic(int argc, const char **argv);
int bench_mem_memcpy(int argc, const char **argv);
int bench_mem_memset(int argc, const char **argv);
int bench_futex_hash(int argc, const char **argv);
diff --git a/tools/perf/bench/syscall.c b/tools/perf/bench/syscall.c
new file mode 100644
index 000000000000..409f84a4fe4f
--- /dev/null
+++ b/tools/perf/bench/syscall.c
@@ -0,0 +1,78 @@
+/*
+ *
+ * syscall.c
+ *
+ * syscall: Benchmark for system call performance
+ */
+#include "../perf.h"
+#include "../util/util.h"
+#include <subcmd/parse-options.h>
+#include "../builtin.h"
+#include "bench.h"
+
+#include <stdio.h>
+#include <sys/time.h>
+#include <sys/syscall.h>
+
+#define LOOPS_DEFAULT 10000000
+static int loops = LOOPS_DEFAULT;
+
+static const struct option options[] = {
+ OPT_INTEGER('l', "loop", &loops, "Specify number of loops"),
+ OPT_END()
+};
+
+static const char * const bench_syscall_usage[] = {
+ "perf bench syscall <options>",
+ NULL
+};
+
+int bench_syscall_basic(int argc, const char **argv)
+{
+ struct timeval start, stop, diff;
+ unsigned long long result_usec = 0;
+ int i;
+
+ argc = parse_options(argc, argv, options, bench_syscall_usage, 0);
+
+ gettimeofday(&start, NULL);
+
+ for (i = 0; i < loops; i++)
+ getppid();
+
+ gettimeofday(&stop, NULL);
+ timersub(&stop, &start, &diff);
+
+ switch (bench_format) {
+ case BENCH_FORMAT_DEFAULT:
+ printf("# Executed %'d getppid() calls\n", loops);
+
+ result_usec = diff.tv_sec * 1000000;
+ result_usec += diff.tv_usec;
+
+ printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",
+ diff.tv_sec,
+ (unsigned long) (diff.tv_usec/1000));
+
+ printf(" %14lf usecs/op\n",
+ (double)result_usec / (double)loops);
+ printf(" %'14d ops/sec\n",
+ (int)((double)loops /
+ ((double)result_usec / (double)1000000)));
+ break;
+
+ case BENCH_FORMAT_SIMPLE:
+ printf("%lu.%03lu\n",
+ diff.tv_sec,
+ (unsigned long) (diff.tv_usec / 1000));
+ break;
+
+ default:
+ /* reaching here is something disaster */
+ fprintf(stderr, "Unknown format:%d\n", bench_format);
+ exit(1);
+ break;
+ }
+
+ return 0;
+}
diff --git a/tools/perf/builtin-bench.c b/tools/perf/builtin-bench.c
index 334c77ffc1d9..017029765404 100644
--- a/tools/perf/builtin-bench.c
+++ b/tools/perf/builtin-bench.c
@@ -11,6 +11,7 @@
* Available benchmark collection list:
*
* sched ... scheduler and IPC performance
+ * syscall ... System call performance
* mem ... memory access performance
* numa ... NUMA scheduling and MM performance
* futex ... Futex performance
@@ -50,6 +51,12 @@ static struct bench sched_benchmarks[] = {
{ NULL, NULL, NULL }
};
+static struct bench syscall_benchmarks[] = {
+ { "basic", "Benchmark for basic getppid(2) calls", bench_syscall_basic },
+ { "all", "Run all syscall benchmarks", NULL },
+ { NULL, NULL, NULL },
+};
+
static struct bench mem_benchmarks[] = {
{ "memcpy", "Benchmark for memcpy() functions", bench_mem_memcpy },
{ "memset", "Benchmark for memset() functions", bench_mem_memset },
@@ -85,6 +92,7 @@ struct collection {
static struct collection collections[] = {
{ "sched", "Scheduler and IPC benchmarks", sched_benchmarks },
+ { "syscall", "System call benchmarks", syscall_benchmarks },
{ "mem", "Memory access benchmarks", mem_benchmarks },
#ifdef HAVE_LIBNUMA_SUPPORT
{ "numa", "NUMA scheduling and MM benchmarks", numa_benchmarks },
--
2.16.4