/*
 * Out Of Memory (OOM) for MEMCG and CPUSET
 *
 * The program is designed to cope with unpredictable like amount and
 * system physical memory, swap size and other VMM technology like KSM,
 * memcg, memory hotplug and so on which may affect the OOM
 * behaviours. It simply increase the memory consumption 3G each time
 * until all the available memory is consumed and OOM is triggered.
 *
 * Copyright (C) 2013-2017  Red Hat, Inc.
 *
 * This program is free software;  you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 */

#include "config.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include "numa_helper.h"
#include "mem.h"

#if HAVE_NUMA_H && HAVE_LINUX_MEMPOLICY_H && HAVE_NUMAIF_H \
	&& HAVE_MPOL_CONSTANTS

static void verify_oom(void)
{
	int swap_acc_on = 1;

#if __WORDSIZE == 32
	tst_brk(TCONF, "test is not designed for 32-bit system.");
#endif

	tst_res(TINFO, "OOM on CPUSET & MEMCG...");
	testoom(0, 0, ENOMEM, 1);

	/*
	 * Under NUMA system, the migration of cpuset's memory
	 * is in charge of cpuset.memory_migrate, we can write
	 * 1 to cpuset.memory_migrate to enable the migration.
	 */
	if (is_numa(NULL, NH_MEMS, 2)) {
		write_cpuset_files(CPATH_NEW, "memory_migrate", "1");
		tst_res(TINFO, "OOM on CPUSET & MEMCG with "
				"cpuset.memory_migrate=1");
		testoom(0, 0, ENOMEM, 1);
	}

	if (access(MEMCG_SW_LIMIT, F_OK) == -1) {
		if (errno == ENOENT) {
			tst_res(TCONF, "memcg swap accounting is disabled");
			swap_acc_on = 0;
		} else
			tst_brk(TBROK|TERRNO, "access");
	}

	if (swap_acc_on) {
		tst_res(TINFO, "OOM on CPUSET & MEMCG with "
				"special memswap limitation:");
		SAFE_FILE_PRINTF(MEMCG_SW_LIMIT, "%ld", TESTMEM);
		testoom(0, 0, ENOMEM, 1);

		tst_res(TINFO, "OOM on CPUSET & MEMCG with "
				"disabled memswap limitation:");
		SAFE_FILE_PRINTF(MEMCG_SW_LIMIT, "-1");
		testoom(0, 0, ENOMEM, 1);
	}
}

void setup(void)
{
	int ret, memnode;

	if (!is_numa(NULL, NH_MEMS, 1))
		tst_brk(TCONF, "requires NUMA with at least 1 node");

	overcommit = get_sys_tune("overcommit_memory");
	set_sys_tune("overcommit_memory", 1, 1);

	mount_mem("memcg", "cgroup", "memory", MEMCG_PATH, MEMCG_PATH_NEW);
	mount_mem("cpuset", "cpuset", NULL, CPATH, CPATH_NEW);
	write_memcg();

	/*
	 * Some nodes do not contain memory, so use
	 * get_allowed_nodes(NH_MEMS) to get a memory
	 * node. This operation also applies to Non-NUMA
	 * systems.
	 */
	ret = get_allowed_nodes(NH_MEMS, 1, &memnode);
	if (ret < 0)
		tst_brk(TBROK, "Failed to get a memory node "
			      "using get_allowed_nodes()");
	write_cpusets(memnode);
}

void cleanup(void)
{
	set_sys_tune("overcommit_memory", overcommit, 0);
	umount_mem(CPATH, CPATH_NEW);
	umount_mem(MEMCG_PATH, MEMCG_PATH_NEW);
}

static struct tst_test test = {
	.needs_root = 1,
	.forks_child = 1,
	.timeout = -1,
	.setup = setup,
	.cleanup = cleanup,
	.test_all = verify_oom,
};

#else /* no NUMA */
	TST_TEST_TCONF("no NUMA development packages installed.");
#endif
