Re: [LTP] [PATCH v4] syscalls/nice05: Add testcase for nice() syscall

[zhaogongyi via ltp <ltp@lists.linux.it>]

Hi Cyril,

Thanks for your review! I have resubmit a patch according to your suggestion. Please see: https://patchwork.ozlabs.org/project/ltp/patch/20220824095144.259871-1-zhaogongyi@huawei.com/

Best Wishes,
Gongyi

> 
> Hi!
> > Add test verifies that the low nice thread executes more time than the
> > high nice thread since the two thread binded on the same cpu.
> 
> Looks very good now, there are few very minor points see below.
> 
> > Signed-off-by: Zhao Gongyi <zhaogongyi@huawei.com>
> > ---
> > v3->v4: Replace getting exec time from sum_exec_runtime with
> pthread_getcpuclockid().
> >
> >  runtest/syscalls                          |   1 +
> >  testcases/kernel/syscalls/nice/.gitignore |   1 +
> >  testcases/kernel/syscalls/nice/Makefile   |   2 +
> >  testcases/kernel/syscalls/nice/nice05.c   | 188
> ++++++++++++++++++++++
> >  4 files changed, 192 insertions(+)
> >  create mode 100644 testcases/kernel/syscalls/nice/nice05.c
> >
> > diff --git a/runtest/syscalls b/runtest/syscalls index
> > 9d58e0aa1..98fcbbe1e 100644
> > --- a/runtest/syscalls
> > +++ b/runtest/syscalls
> > @@ -903,6 +903,7 @@ nice01 nice01
> >  nice02 nice02
> >  nice03 nice03
> >  nice04 nice04
> > +nice05 nice05
> >
> >  open01 open01
> >  open01A symlink01 -T open01
> > diff --git a/testcases/kernel/syscalls/nice/.gitignore
> > b/testcases/kernel/syscalls/nice/.gitignore
> > index 9d7a1bb43..58d64779e 100644
> > --- a/testcases/kernel/syscalls/nice/.gitignore
> > +++ b/testcases/kernel/syscalls/nice/.gitignore
> > @@ -2,3 +2,4 @@
> >  /nice02
> >  /nice03
> >  /nice04
> > +/nice05
> > diff --git a/testcases/kernel/syscalls/nice/Makefile
> > b/testcases/kernel/syscalls/nice/Makefile
> > index 044619fb8..02e78a295 100644
> > --- a/testcases/kernel/syscalls/nice/Makefile
> > +++ b/testcases/kernel/syscalls/nice/Makefile
> > @@ -3,6 +3,8 @@
> >
> >  top_srcdir		?= ../../../..
> >
> > +nice05: CFLAGS += -pthread
> > +
> >  include $(top_srcdir)/include/mk/testcases.mk
> >
> >  include $(top_srcdir)/include/mk/generic_leaf_target.mk
> > diff --git a/testcases/kernel/syscalls/nice/nice05.c
> > b/testcases/kernel/syscalls/nice/nice05.c
> > new file mode 100644
> > index 000000000..8ef33f932
> > --- /dev/null
> > +++ b/testcases/kernel/syscalls/nice/nice05.c
> > @@ -0,0 +1,188 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * Copyright(c) 2022 Huawei Technologies Co., Ltd
> > + * Author: Li Mengfei <limengfei4@huawei.com>
> > + *         Zhao Gongyi <zhaogongyi@huawei.com>
> > + */
> > +
> > +/*\
> > + * [Description]
> > + *
> > + * 1. Create a high nice thread and a low nice thread, the main
> > + *    thread wake them at the same time
> > + * 2. Both threads run on the same CPU
> > + * 3. Verify that the low nice thread executes more time than
> > + *    the high nice thread
> > + */
> > +
> > +#define _GNU_SOURCE
> > +#include <pthread.h>
> > +#include <sys/types.h>
> > +#include <stdio.h>
> > +#include "tst_test.h"
> > +#include "tst_safe_pthread.h"
> > +#include "lapi/syscalls.h"
> > +
> > +#define SEC2NS(sec)  ((sec) * 1000000000LL)
> > +
> > +static pthread_barrier_t barrier;
> > +static int some_cpu;
> > +static cpu_set_t *set;
> > +
> > +static void set_nice(int nice_inc)
> > +{
> > +	int orig_nice;
> > +
> > +	orig_nice = SAFE_GETPRIORITY(PRIO_PROCESS, 0);
> > +
> > +	TEST(nice(nice_inc));
> > +
> > +	if (TST_RET != (orig_nice + nice_inc)) {
> > +		tst_brk(TBROK | TTERRNO, "nice(%d) returned %li, expected %i",
> > +			nice_inc, TST_RET, orig_nice + nice_inc);
> > +	}
> > +
> > +	if (TST_ERR)
> > +		tst_brk(TBROK | TTERRNO, "nice(%d) failed", nice_inc); }
> > +
> > +static void *nice_low_thread(void *arg) {
> > +	volatile int number = 0;
> > +
> > +	set_nice((intptr_t)arg);
> > +	TEST(pthread_barrier_wait(&barrier));
> > +	if (TST_RET != 0 && TST_RET != PTHREAD_BARRIER_SERIAL_THREAD)
> > +		tst_brk(TBROK | TRERRNO, "pthread_barrier_wait() failed");
> > +
> > +	while (1)
> > +		number++;
> > +
> > +	return NULL;
> > +}
> > +
> > +static void *nice_high_thread(void *arg) {
> > +	volatile int number = 0;
> > +
> > +	set_nice((intptr_t)arg);
> > +	TEST(pthread_barrier_wait(&barrier));
> > +	if (TST_RET != 0 && TST_RET != PTHREAD_BARRIER_SERIAL_THREAD)
> > +		tst_brk(TBROK | TRERRNO, "pthread_barrier_wait() failed");
> 
> It may be worth to add SAFE_PTHREAD_BARRIER_WAIT() to the
> tst_safe_pthread_h to make the code nicer.
> 
> > +	while (1)
> > +		number++;
> > +
> > +	return NULL;
> > +}
> > +
> > +static void setup(void)
> > +{
> > +	size_t size;
> > +	size_t i;
> > +	int nrcpus = 1024;
> > +
> > +	set = CPU_ALLOC(nrcpus);
> > +	if (!set)
> > +		tst_brk(TBROK | TERRNO, "CPU_ALLOC()");
> > +
> > +	size = CPU_ALLOC_SIZE(nrcpus);
> > +	CPU_ZERO_S(size, set);
> > +	if (sched_getaffinity(0, size, set) < 0)
> > +		tst_brk(TBROK | TERRNO, "sched_getaffinity()");
> > +
> > +	for (i = 0; i < size * 8; i++)
> > +		if (CPU_ISSET_S(i, size, set))
> > +			some_cpu = i;
> > +
> > +	CPU_ZERO_S(size, set);
> > +	CPU_SET_S(some_cpu, size, set);
> > +	if (sched_setaffinity(0, size, set) < 0)
> > +		tst_brk(TBROK | TERRNO, "sched_setaffinity()"); }
> > +
> > +static void cleanup(void)
> > +{
> > +	if (set)
> > +		CPU_FREE(set);
> 
> This is very minor however we do not seem to use set anywhere outside
> the setup so we may as well free it there.
> 
> > +}
> > +
> > +static void verify_nice(void)
> > +{
> > +	intptr_t nice_inc_high = -1;
> > +	intptr_t nice_inc_low = -2;
> > +	clockid_t nice_low_clockid, nice_high_clockid;
> > +	struct timespec nice_high_ts, nice_low_ts;
> > +	long long delta;
> > +	pid_t pid;
> > +	pthread_t thread[2];
> > +
> > +	pid = SAFE_FORK();
> > +	if (!pid) {
> 
> Is there a reason why we run the actual test in the child?
> 
> > +		TEST(pthread_barrier_init(&barrier, NULL, 3));
> > +		if (TST_RET != 0) {
> > +			tst_brk(TBROK | TTERRNO,
> > +					"pthread_barrier_init() failed");
> > +		}
> > +
> > +		SAFE_PTHREAD_CREATE(&thread[0], NULL, nice_high_thread,
> > +				(void *)nice_inc_high);
> > +		SAFE_PTHREAD_CREATE(&thread[1], NULL, nice_low_thread,
> > +				(void *)nice_inc_low);
> > +
> > +		TEST(pthread_barrier_wait(&barrier));
> > +		if (TST_RET != 0 && TST_RET !=
> PTHREAD_BARRIER_SERIAL_THREAD) {
> > +			tst_brk(TBROK | TTERRNO,
> > +					"pthread_barrier_wait() failed");
> > +		}
> > +
> > +		sleep(tst_remaining_runtime());
> > +
> > +		if (pthread_getcpuclockid(thread[1], &nice_low_clockid) != 0) {
> > +			perror("clock_getcpuclockid");
> > +			tst_brk(TBROK | TERRNO,
> > +					"clock_getcpuclockid() failed");
> > +		}
> > +		if (pthread_getcpuclockid(thread[0], &nice_high_clockid) != 0) {
> > +			perror("clock_getcpuclockid");
> > +			tst_brk(TBROK | TERRNO,
> > +					"clock_getcpuclockid() failed");
> > +		}
> > +
> > +		if (clock_gettime(nice_low_clockid, &nice_low_ts) == -1) {
> > +			tst_brk(TBROK | TERRNO,
> > +					"clock_getcpuclockid() failed");
> > +		}
> > +
> > +		if (clock_gettime(nice_high_clockid, &nice_high_ts) == -1) {
> > +			tst_brk(TBROK | TERRNO,
> > +					"clock_getcpuclockid() failed");
> > +		}
> 
> We do have SAFE_CLOCK_GETTIME() please use them.
> 
> > +		tst_res(TINFO, "Nice low thread CPU time: %ld.%09ld s",
> > +			nice_low_ts.tv_sec, nice_low_ts.tv_nsec);
> > +		tst_res(TINFO, "Nice high thread CPU time: %ld.%09ld s",
> > +			nice_high_ts.tv_sec, nice_high_ts.tv_nsec);
> > +
> > +		delta = SEC2NS(nice_low_ts.tv_sec - nice_high_ts.tv_sec) +
> > +			(nice_low_ts.tv_nsec - nice_high_ts.tv_nsec);
> 
> We do have a tst_timespec_diff_{us,ns,ms} functions in the tst_timer.h so
> we may as well use them.
> 
> > +		if (delta < 0) {
> > +			tst_res(TFAIL, "executes less cycles than "
> > +				"the high nice thread, delta: %lld ns", delta);
> > +		} else {
> > +			tst_res(TPASS, "executes more cycles than "
> > +				"the high nice thread, delta: %lld ns", delta);
> > +		}
> > +		return;
> > +	}
> > +	SAFE_WAIT(NULL);
> > +}
> > +
> > +static struct tst_test test = {
> > +	.setup = setup,
> > +	.cleanup = cleanup,
> > +	.test_all = verify_nice,
> > +	.needs_root = 1,
> > +	.forks_child = 1,
> > +	.max_runtime = 3,
> > +};
> > --
> > 2.17.1
> >
> 
> --
> Cyril Hrubis
> chrubis@suse.cz

-- 
Mailing list info: https://lists.linux.it/listinfo/ltp