kselftest: Add test for core sched prctl interface (9f269900) · Commits · jan.koester / Linux

tools/testing/selftests/sched/.gitignore

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		cs_prctl_test

tools/testing/selftests/sched/Makefile

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		# SPDX-License-Identifier: GPL-2.0+

		ifneq ($(shell $(CC) --version 2>&1 \| head -n 1 \| grep clang),)
		CLANG_FLAGS += -no-integrated-as
		endif

		CFLAGS += -O2 -Wall -g -I./ -I../../../../usr/include/ -Wl,-rpath=./ \
		$(CLANG_FLAGS)
		LDLIBS += -lpthread

		TEST_GEN_FILES := cs_prctl_test
		TEST_PROGS := cs_prctl_test

		include ../lib.mk

tools/testing/selftests/sched/config

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		CONFIG_SCHED_DEBUG=y

tools/testing/selftests/sched/cs_prctl_test.c

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		// SPDX-License-Identifier: GPL-2.0-only
		/*
		* Use the core scheduling prctl() to test core scheduling cookies control.
		*
		* Copyright (c) 2021 Oracle and/or its affiliates.
		* Author: Chris Hyser <chris.hyser@oracle.com>
		*
		*
		* This library is free software; you can redistribute it and/or modify it
		* under the terms of version 2.1 of the GNU Lesser General Public License as
		* published by the Free Software Foundation.
		*
		* This library is distributed in the hope that it will be useful, but WITHOUT
		* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
		* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
		* for more details.
		*
		* You should have received a copy of the GNU Lesser General Public License
		* along with this library; if not, see <http://www.gnu.org/licenses>.
		*/

		#define _GNU_SOURCE
		#include <sys/eventfd.h>
		#include <sys/wait.h>
		#include <sys/types.h>
		#include <sched.h>
		#include <sys/prctl.h>
		#include <sys/types.h>
		#include <sys/wait.h>
		#include <unistd.h>
		#include <time.h>
		#include <stdio.h>
		#include <stdlib.h>
		#include <string.h>

		#if __GLIBC_PREREQ(2, 30) == 0
		#include <sys/syscall.h>
		static pid_t gettid(void)
		{
		return syscall(SYS_gettid);
		}
		#endif

		#ifndef PR_SCHED_CORE
		#define PR_SCHED_CORE 62
		# define PR_SCHED_CORE_GET 0
		# define PR_SCHED_CORE_CREATE 1 /* create unique core_sched cookie */
		# define PR_SCHED_CORE_SHARE_TO 2 /* push core_sched cookie to pid */
		# define PR_SCHED_CORE_SHARE_FROM 3 /* pull core_sched cookie to pid */
		# define PR_SCHED_CORE_MAX 4
		#endif

		#define MAX_PROCESSES 128
		#define MAX_THREADS 128

		static const char USAGE[] = "cs_prctl_test [options]\n"
		" options:\n"
		" -P : number of processes to create.\n"
		" -T : number of threads per process to create.\n"
		" -d : delay time to keep tasks alive.\n"
		" -k : keep tasks alive until keypress.\n";

		enum pid_type {PIDTYPE_PID = 0, PIDTYPE_TGID, PIDTYPE_PGID};

		const int THREAD_CLONE_FLAGS = CLONE_THREAD \| CLONE_SIGHAND \| CLONE_FS \| CLONE_VM \| CLONE_FILES;

		static int _prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4,
		unsigned long arg5)
		{
		int res;

		res = prctl(option, arg2, arg3, arg4, arg5);
		printf("%d = prctl(%d, %ld, %ld, %ld, %lx)\n", res, option, (long)arg2, (long)arg3,
		(long)arg4, arg5);
		return res;
		}

		#define STACK_SIZE (1024 * 1024)

		#define handle_error(msg) __handle_error(__FILE__, __LINE__, msg)
		static void __handle_error(char fn, int ln, char msg)
		{
		printf("(%s:%d) - ", fn, ln);
		perror(msg);
		exit(EXIT_FAILURE);
		}

		static void handle_usage(int rc, char *msg)
		{
		puts(USAGE);
		puts(msg);
		putchar('\n');
		exit(rc);
		}

		static unsigned long get_cs_cookie(int pid)
		{
		unsigned long long cookie;
		int ret;

		ret = prctl(PR_SCHED_CORE, PR_SCHED_CORE_GET, pid, PIDTYPE_PID,
		(unsigned long)&cookie);
		if (ret) {
		printf("Not a core sched system\n");
		return -1UL;
		}

		return cookie;
		}

		struct child_args {
		int num_threads;
		int pfd[2];
		int cpid;
		int thr_tids[MAX_THREADS];
		};

		static int child_func_thread(void __attribute__((unused))*arg)
		{
		while (1)
		usleep(20000);
		return 0;
		}

		static void create_threads(int num_threads, int thr_tids[])
		{
		void *child_stack;
		pid_t tid;
		int i;

		for (i = 0; i < num_threads; ++i) {
		child_stack = malloc(STACK_SIZE);
		if (!child_stack)
		handle_error("child stack allocate");

		tid = clone(child_func_thread, child_stack + STACK_SIZE, THREAD_CLONE_FLAGS, NULL);
		if (tid == -1)
		handle_error("clone thread");
		thr_tids[i] = tid;
		}
		}

		static int child_func_process(void *arg)
		{
		struct child_args ca = (struct child_args )arg;

		close(ca->pfd[0]);

		create_threads(ca->num_threads, ca->thr_tids);

		write(ca->pfd[1], &ca->thr_tids, sizeof(int) * ca->num_threads);
		close(ca->pfd[1]);

		while (1)
		usleep(20000);
		return 0;
		}

		static unsigned char child_func_process_stack[STACK_SIZE];

		void create_processes(int num_processes, int num_threads, struct child_args proc[])
		{
		pid_t cpid;
		int i;

		for (i = 0; i < num_processes; ++i) {
		proc[i].num_threads = num_threads;

		if (pipe(proc[i].pfd) == -1)
		handle_error("pipe() failed");

		cpid = clone(child_func_process, child_func_process_stack + STACK_SIZE,
		SIGCHLD, &proc[i]);
		proc[i].cpid = cpid;
		close(proc[i].pfd[1]);
		}

		for (i = 0; i < num_processes; ++i) {
		read(proc[i].pfd[0], &proc[i].thr_tids, sizeof(int) * proc[i].num_threads);
		close(proc[i].pfd[0]);
		}
		}

		void disp_processes(int num_processes, struct child_args proc[])
		{
		int i, j;

		printf("tid=%d, / tgid=%d / pgid=%d: %lx\n", gettid(), getpid(), getpgid(0),
		get_cs_cookie(getpid()));

		for (i = 0; i < num_processes; ++i) {
		printf(" tid=%d, / tgid=%d / pgid=%d: %lx\n", proc[i].cpid, proc[i].cpid,
		getpgid(proc[i].cpid), get_cs_cookie(proc[i].cpid));
		for (j = 0; j < proc[i].num_threads; ++j) {
		printf(" tid=%d, / tgid=%d / pgid=%d: %lx\n", proc[i].thr_tids[j],
		proc[i].cpid, getpgid(0), get_cs_cookie(proc[i].thr_tids[j]));
		}
		}
		puts("\n");
		}

		static int errors;

		#define validate(v) _validate(__LINE__, v, #v)
		void _validate(int line, int val, char *msg)
		{
		if (!val) {
		++errors;
		printf("(%d) FAILED: %s\n", line, msg);
		} else {
		printf("(%d) PASSED: %s\n", line, msg);
		}
		}

		int main(int argc, char *argv[])
		{
		struct child_args procs[MAX_PROCESSES];

		int keypress = 0;
		int num_processes = 2;
		int num_threads = 3;
		int delay = 0;
		int res = 0;
		int pidx;
		int pid;
		int opt;

		while ((opt = getopt(argc, argv, ":hkT:P:d:")) != -1) {
		switch (opt) {
		case 'P':
		num_processes = (int)strtol(optarg, NULL, 10);
		break;
		case 'T':
		num_threads = (int)strtoul(optarg, NULL, 10);
		break;
		case 'd':
		delay = (int)strtol(optarg, NULL, 10);
		break;
		case 'k':
		keypress = 1;
		break;
		case 'h':
		printf(USAGE);
		exit(EXIT_SUCCESS);
		default:
		handle_usage(20, "unknown option");
		}
		}

		if (num_processes < 1 \|\| num_processes > MAX_PROCESSES)
		handle_usage(1, "Bad processes value");

		if (num_threads < 1 \|\| num_threads > MAX_THREADS)
		handle_usage(2, "Bad thread value");

		if (keypress)
		delay = -1;

		srand(time(NULL));

		/* put into separate process group */
		if (setpgid(0, 0) != 0)
		handle_error("process group");

		printf("\n## Create a thread/process/process group hiearchy\n");
		create_processes(num_processes, num_threads, procs);
		disp_processes(num_processes, procs);
		validate(get_cs_cookie(0) == 0);

		printf("\n## Set a cookie on entire process group\n");
		if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_CREATE, 0, PIDTYPE_PGID, 0) < 0)
		handle_error("core_sched create failed -- PGID");
		disp_processes(num_processes, procs);

		validate(get_cs_cookie(0) != 0);

		/* get a random process pid */
		pidx = rand() % num_processes;
		pid = procs[pidx].cpid;

		validate(get_cs_cookie(0) == get_cs_cookie(pid));
		validate(get_cs_cookie(0) == get_cs_cookie(procs[pidx].thr_tids[0]));

		printf("\n## Set a new cookie on entire process/TGID [%d]\n", pid);
		if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_CREATE, pid, PIDTYPE_TGID, 0) < 0)
		handle_error("core_sched create failed -- TGID");
		disp_processes(num_processes, procs);

		validate(get_cs_cookie(0) != get_cs_cookie(pid));
		validate(get_cs_cookie(pid) != 0);
		validate(get_cs_cookie(pid) == get_cs_cookie(procs[pidx].thr_tids[0]));

		printf("\n## Copy the cookie of current/PGID[%d], to pid [%d] as PIDTYPE_PID\n",
		getpid(), pid);
		if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_TO, pid, PIDTYPE_PID, 0) < 0)
		handle_error("core_sched share to itself failed -- PID");
		disp_processes(num_processes, procs);

		validate(get_cs_cookie(0) == get_cs_cookie(pid));
		validate(get_cs_cookie(pid) != 0);
		validate(get_cs_cookie(pid) != get_cs_cookie(procs[pidx].thr_tids[0]));

		printf("\n## Copy cookie from a thread [%d] to current/PGID [%d] as PIDTYPE_PID\n",
		procs[pidx].thr_tids[0], getpid());
		if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_FROM, procs[pidx].thr_tids[0],
		PIDTYPE_PID, 0) < 0)
		handle_error("core_sched share from thread failed -- PID");
		disp_processes(num_processes, procs);

		validate(get_cs_cookie(0) == get_cs_cookie(procs[pidx].thr_tids[0]));
		validate(get_cs_cookie(pid) != get_cs_cookie(procs[pidx].thr_tids[0]));

		printf("\n## Copy cookie from current [%d] to current as pidtype PGID\n", getpid());
		if (_prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_TO, 0, PIDTYPE_PGID, 0) < 0)
		handle_error("core_sched share to self failed -- PGID");
		disp_processes(num_processes, procs);

		validate(get_cs_cookie(0) == get_cs_cookie(pid));
		validate(get_cs_cookie(pid) != 0);
		validate(get_cs_cookie(pid) == get_cs_cookie(procs[pidx].thr_tids[0]));

		if (errors) {
		printf("TESTS FAILED. errors: %d\n", errors);
		res = 10;
		} else {
		printf("SUCCESS !!!\n");
		}

		if (keypress)
		getchar();
		else
		sleep(delay);

		for (pidx = 0; pidx < num_processes; ++pidx)
		kill(procs[pidx].cpid, 15);

		return res;
		}