Re: [PATCH] perf bench syscall: Add fork syscall benchmark

From: Arnaldo Carvalho de Melo
Date: Mon Mar 27 2023 - 07:32:56 EST


Em Fri, Mar 24, 2023 at 09:31:25PM -0700, Namhyung Kim escreveu:
> Hello,
>
> On Mon, Mar 20, 2023 at 11:57 PM Tiezhu Yang <yangtiezhu@xxxxxxxxxxx> wrote:
> >
> > This is a follow up patch for the execve bench which is actually
> > fork + execve, it makes sense to add the fork syscall benchmark
> > to compare the execve part precisely.
> >
> > Some archs have no __NR_fork definition which is used only as a
> > check condition to call test_fork(), let us just define it as -1
> > to avoid build error.
> >
> > Suggested-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> > Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
>
> Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>

Thanks, applied.

- Arnaldo


> Thanks,
> Namhyung
>
>
> > ---
> > tools/arch/x86/include/uapi/asm/unistd_32.h | 4 ++--
> > tools/arch/x86/include/uapi/asm/unistd_64.h | 3 +++
> > tools/perf/bench/bench.h | 1 +
> > tools/perf/bench/syscall.c | 35 +++++++++++++++++++++++++++++
> > tools/perf/builtin-bench.c | 1 +
> > 5 files changed, 42 insertions(+), 2 deletions(-)
> >
> > diff --git a/tools/arch/x86/include/uapi/asm/unistd_32.h b/tools/arch/x86/include/uapi/asm/unistd_32.h
> > index 2712d5e..b8ddfc4 100644
> > --- a/tools/arch/x86/include/uapi/asm/unistd_32.h
> > +++ b/tools/arch/x86/include/uapi/asm/unistd_32.h
> > @@ -1,6 +1,6 @@
> > /* SPDX-License-Identifier: GPL-2.0 */
> > -#ifndef __NR_execve
> > -#define __NR_execve 11
> > +#ifndef __NR_fork
> > +#define __NR_fork 2
> > #endif
> > #ifndef __NR_getppid
> > #define __NR_getppid 64
> > diff --git a/tools/arch/x86/include/uapi/asm/unistd_64.h b/tools/arch/x86/include/uapi/asm/unistd_64.h
> > index a6f7fe8..f70d2cad 100644
> > --- a/tools/arch/x86/include/uapi/asm/unistd_64.h
> > +++ b/tools/arch/x86/include/uapi/asm/unistd_64.h
> > @@ -1,4 +1,7 @@
> > /* SPDX-License-Identifier: GPL-2.0 */
> > +#ifndef __NR_fork
> > +#define __NR_fork 57
> > +#endif
> > #ifndef __NR_execve
> > #define __NR_execve 59
> > #endif
> > diff --git a/tools/perf/bench/bench.h b/tools/perf/bench/bench.h
> > index e438931..edfc257 100644
> > --- a/tools/perf/bench/bench.h
> > +++ b/tools/perf/bench/bench.h
> > @@ -23,6 +23,7 @@ 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_syscall_getpgid(int argc, const char **argv);
> > +int bench_syscall_fork(int argc, const char **argv);
> > int bench_syscall_execve(int argc, const char **argv);
> > int bench_mem_memcpy(int argc, const char **argv);
> > int bench_mem_memset(int argc, const char **argv);
> > diff --git a/tools/perf/bench/syscall.c b/tools/perf/bench/syscall.c
> > index fe79f7f..ea4dfc07 100644
> > --- a/tools/perf/bench/syscall.c
> > +++ b/tools/perf/bench/syscall.c
> > @@ -18,6 +18,10 @@
> > #include <unistd.h>
> > #include <stdlib.h>
> >
> > +#ifndef __NR_fork
> > +#define __NR_fork -1
> > +#endif
> > +
> > #define LOOPS_DEFAULT 10000000
> > static int loops = LOOPS_DEFAULT;
> >
> > @@ -31,6 +35,23 @@ static const char * const bench_syscall_usage[] = {
> > NULL
> > };
> >
> > +static void test_fork(void)
> > +{
> > + pid_t pid = fork();
> > +
> > + if (pid < 0) {
> > + fprintf(stderr, "fork failed\n");
> > + exit(1);
> > + } else if (pid == 0) {
> > + exit(0);
> > + } else {
> > + if (waitpid(pid, NULL, 0) < 0) {
> > + fprintf(stderr, "waitpid failed\n");
> > + exit(1);
> > + }
> > + }
> > +}
> > +
> > static void test_execve(void)
> > {
> > const char *pathname = "/bin/true";
> > @@ -71,6 +92,12 @@ static int bench_syscall_common(int argc, const char **argv, int syscall)
> > case __NR_getpgid:
> > getpgid(0);
> > break;
> > + case __NR_fork:
> > + test_fork();
> > + /* Only loop 10000 times to save time */
> > + if (i == 10000)
> > + loops = 10000;
> > + break;
> > case __NR_execve:
> > test_execve();
> > /* Only loop 10000 times to save time */
> > @@ -92,6 +119,9 @@ static int bench_syscall_common(int argc, const char **argv, int syscall)
> > case __NR_getpgid:
> > name = "getpgid()";
> > break;
> > + case __NR_fork:
> > + name = "fork()";
> > + break;
> > case __NR_execve:
> > name = "execve()";
> > break;
> > @@ -143,6 +173,11 @@ int bench_syscall_getpgid(int argc, const char **argv)
> > return bench_syscall_common(argc, argv, __NR_getpgid);
> > }
> >
> > +int bench_syscall_fork(int argc, const char **argv)
> > +{
> > + return bench_syscall_common(argc, argv, __NR_fork);
> > +}
> > +
> > int bench_syscall_execve(int argc, const char **argv)
> > {
> > return bench_syscall_common(argc, argv, __NR_execve);
> > diff --git a/tools/perf/builtin-bench.c b/tools/perf/builtin-bench.c
> > index 814e9af..d0fcc3c 100644
> > --- a/tools/perf/builtin-bench.c
> > +++ b/tools/perf/builtin-bench.c
> > @@ -53,6 +53,7 @@ static struct bench sched_benchmarks[] = {
> > static struct bench syscall_benchmarks[] = {
> > { "basic", "Benchmark for basic getppid(2) calls", bench_syscall_basic },
> > { "getpgid", "Benchmark for getpgid(2) calls", bench_syscall_getpgid },
> > + { "fork", "Benchmark for fork(2) calls", bench_syscall_fork },
> > { "execve", "Benchmark for execve(2) calls", bench_syscall_execve },
> > { "all", "Run all syscall benchmarks", NULL },
> > { NULL, NULL, NULL },
> > --
> > 2.1.0
> >

--

- Arnaldo