Commit 1854b97e authored by Andrei Vagin's avatar Andrei Vagin Committed by Thomas Gleixner
Browse files

selftests/timens: Add a simple perf test for clock_gettime() 



Output on success:
1..4
 ok 1 host:	clock:  monotonic	cycles:	 148323947
 ok 2 host:	clock:   boottime	cycles:	 148577503
 ok 3 ns:	clock:  monotonic	cycles:	 137659217
 ok 4 ns:	clock:   boottime	cycles:	 137959154
 # Pass 4 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0

Output with lack of permissions:
 1..4
 ok 1 host:	clock:  monotonic	cycles:	 145671139
 ok 2 host:	clock:   boottime	cycles:	 146958357
 not ok 3 # SKIP need to run as root

Output without support of time namespaces:
 1..4
 ok 1 host:	clock:  monotonic	cycles:	 145671139
 ok 2 host:	clock:   boottime	cycles:	 146958357
 not ok 3 # SKIP Time namespaces are not supported

Co-developed-by: default avatarDmitry Safonov <dima@arista.com>
Signed-off-by: default avatarAndrei Vagin <avagin@gmail.com>
Signed-off-by: default avatarDmitry Safonov <dima@arista.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-34-dima@arista.com
parent d5b0117d

tools/testing/selftests/timens/.gitignore

+2 −0
Original line number Diff line number Diff line 
clock_nanosleep

gettime_perf

gettime_perf_cold

procfs

timens

timer

tools/testing/selftests/timens/Makefile

+2 −1
Original line number Diff line number Diff line 
TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs

TEST_GEN_PROGS_EXTENDED := gettime_perf



CFLAGS := -Wall -Werror -pthread

LDFLAGS := -lrt

LDFLAGS := -lrt -ldl



include ../lib.mk

tools/testing/selftests/timens/gettime_perf.c

0 → 100644
+95 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

#define _GNU_SOURCE

#include <sys/types.h>

#include <sys/stat.h>

#include <errno.h>

#include <fcntl.h>

#include <sched.h>

#include <time.h>

#include <stdio.h>

#include <unistd.h>

#include <sys/syscall.h>

#include <dlfcn.h>



#include "log.h"

#include "timens.h"



typedef int (*vgettime_t)(clockid_t, struct timespec *);



vgettime_t vdso_clock_gettime;



static void fill_function_pointers(void)

{

	void *vdso = dlopen("linux-vdso.so.1",

			    RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);

	if (!vdso)

		vdso = dlopen("linux-gate.so.1",

			      RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);

	if (!vdso) {

		pr_err("[WARN]\tfailed to find vDSO\n");

		return;

	}



	vdso_clock_gettime = (vgettime_t)dlsym(vdso, "__vdso_clock_gettime");

	if (!vdso_clock_gettime)

		pr_err("Warning: failed to find clock_gettime in vDSO\n");



}



static void test(clock_t clockid, char *clockstr, bool in_ns)

{

	struct timespec tp, start;

	long i = 0;

	const int timeout = 3;



	vdso_clock_gettime(clockid, &start);

	tp = start;

	for (tp = start; start.tv_sec + timeout > tp.tv_sec ||

			 (start.tv_sec + timeout == tp.tv_sec &&

			  start.tv_nsec > tp.tv_nsec); i++) {

		vdso_clock_gettime(clockid, &tp);

	}



	ksft_test_result_pass("%s:\tclock: %10s\tcycles:\t%10ld\n",

			      in_ns ? "ns" : "host", clockstr, i);

}



int main(int argc, char *argv[])

{

	time_t offset = 10;

	int nsfd;



	ksft_set_plan(8);



	fill_function_pointers();



	test(CLOCK_MONOTONIC, "monotonic", false);

	test(CLOCK_MONOTONIC_COARSE, "monotonic-coarse", false);

	test(CLOCK_MONOTONIC_RAW, "monotonic-raw", false);

	test(CLOCK_BOOTTIME, "boottime", false);



	nscheck();



	if (unshare_timens())

		return 1;



	nsfd = open("/proc/self/ns/time_for_children", O_RDONLY);

	if (nsfd < 0)

		return pr_perror("Can't open a time namespace");



	if (_settime(CLOCK_MONOTONIC, offset))

		return 1;

	if (_settime(CLOCK_BOOTTIME, offset))

		return 1;



	if (setns(nsfd, CLONE_NEWTIME))

		return pr_perror("setns");



	test(CLOCK_MONOTONIC, "monotonic", true);

	test(CLOCK_MONOTONIC_COARSE, "monotonic-coarse", true);

	test(CLOCK_MONOTONIC_RAW, "monotonic-raw", true);

	test(CLOCK_BOOTTIME, "boottime", true);



	ksft_exit_pass();

	return 0;

}

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