perf bench syscall: Add execve syscall benchmark

This commit adds the execve syscall benchmark, more syscall benchmarks
can be added in the future.

Signed-off-by: Tiezhu Yang <[e-mail]>
Acked-by: Namhyung Kim <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/arch/x86/include/uapi/asm/unistd_32.h

···
 /* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __NR_execve
+#define __NR_execve 11
+#endif
 #ifndef __NR_getppid
 #define __NR_getppid 64
 #endif

tools/arch/x86/include/uapi/asm/unistd_64.h

···
 /* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __NR_execve
+#define __NR_execve 59
+#endif
 #ifndef __NR_getppid
 #define __NR_getppid 110
 #endif

tools/perf/bench/bench.h

···
 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_execve(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_mem_find_bit(int argc, const char **argv);

tools/perf/bench/syscall.c

···
 #include <sys/time.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
+#include <sys/wait.h>
 #include <unistd.h>
 #include <stdlib.h>
 
···
 	"perf bench syscall <options>",
 	NULL
 };
+
+static void test_execve(void)
+{
+	const char *pathname = "/bin/true";
+	char *const argv[] = { (char *)pathname, NULL };
+	pid_t pid = fork();
+
+	if (pid < 0) {
+		fprintf(stderr, "fork failed\n");
+		exit(1);
+	} else if (pid == 0) {
+		execve(pathname, argv, NULL);
+		fprintf(stderr, "execve /bin/true failed\n");
+		exit(1);
+	} else {
+		if (waitpid(pid, NULL, 0) < 0) {
+			fprintf(stderr, "waitpid failed\n");
+			exit(1);
+		}
+	}
+}
 
 static int bench_syscall_common(int argc, const char **argv, int syscall)
 {
···
 		case __NR_getpgid:
 			getpgid(0);
 			break;
+		case __NR_execve:
+			test_execve();
+			/* Only loop 10000 times to save time */
+			if (i == 10000)
+				loops = 10000;
+			break;
 		default:
 			break;
 		}
···
 		break;
 	case __NR_getpgid:
 		name = "getpgid()";
+		break;
+	case __NR_execve:
+		name = "execve()";
 		break;
 	default:
 		break;
···
 int bench_syscall_getpgid(int argc, const char **argv)
 {
 	return bench_syscall_common(argc, argv, __NR_getpgid);
+}
+
+int bench_syscall_execve(int argc, const char **argv)
+{
+	return bench_syscall_common(argc, argv, __NR_execve);
 }

tools/perf/builtin-bench.c

···
 static struct bench syscall_benchmarks[] = {
 	{ "basic",	"Benchmark for basic getppid(2) calls",		bench_syscall_basic	},
 	{ "getpgid",	"Benchmark for getpgid(2) calls",		bench_syscall_getpgid	},
+	{ "execve",	"Benchmark for execve(2) calls",		bench_syscall_execve	},
 	{ "all",	"Run all syscall benchmarks",			NULL			},
 	{ NULL,		NULL,						NULL			},
 };