Re: [PATCH] tools/perf-bench: Add basic syscall benchmark

[Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>]

Em Thu, Mar 07, 2019 at 10:52:53AM -0800, Davidlohr Bueso escreveu:
> 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.

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.

Thanks.

- Arnaldo
 
> https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1067469.html
> 
> Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
> ---
>  tools/perf/bench/Build     |  1 +
>  tools/perf/bench/bench.h   |  1 +
>  tools/perf/bench/syscall.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++
>  tools/perf/builtin-bench.c |  8 +++++
>  4 files changed, 90 insertions(+)
>  create mode 100644 tools/perf/bench/syscall.c
> 
> 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..149129cca639
> --- /dev/null
> +++ b/tools/perf/bench/syscall.c
> @@ -0,0 +1,80 @@
> +/*
> + *
> + * 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 <locale.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:
> +		setlocale(LC_NUMERIC, "");
> +		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..4e9dd0f4eced 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() system 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

-- 

- Arnaldo