1// SPDX-License-Identifier: GPL-2.0
2/*\
3 *
4 * [Description]
5 *
6 * Conversion of second kself test in cgroup/test_memcontrol.c.
7 *
8 * Original description:
9 * "This test creates a memory cgroup, allocates some anonymous memory
10 * and some pagecache and check memory.current and some memory.stat
11 * values."
12 *
13 * Note that the V1 rss and cache counters were renamed to anon and
14 * file in V2. Besides error reporting, this test differs from the
15 * kselftest in the following ways:
16 *
17 * . It supports V1.
18 * . It writes instead of reads to fill the page cache. Because no
19 *   pages were allocated on tmpfs.
20 * . It runs on most filesystems available
21 * . On EXFAT and extN we change the margin of error between all and file
22 *   memory to 50%. Because these allocate non-page-cache memory during writes.
23 */
24#define _GNU_SOURCE
25
26#include "memcontrol_common.h"
27
28static size_t page_size;
29static struct tst_cg_group *cg_child;
30static int fd;
31static int file_to_all_error = 10;
32
33static void alloc_anon_50M_check(void)
34{
35	const ssize_t size = MB(50);
36	char *buf, *ptr;
37	ssize_t anon, current;
38	const char *const anon_key_fmt =
39		TST_CG_VER_IS_V1(tst_cg, "memory") ? "rss %zd" : "anon %zd";
40
41	buf = SAFE_MALLOC(size);
42	for (ptr = buf; ptr < buf + size; ptr += page_size)
43		*ptr = 0;
44
45	SAFE_CG_SCANF(cg_child, "memory.current", "%zd", &current);
46	TST_EXP_EXPR(current >= size,
47		     "(memory.current=%zd) >= (size=%zd)", current, size);
48
49	SAFE_CG_LINES_SCANF(cg_child, "memory.stat", anon_key_fmt, &anon);
50
51	TST_EXP_EXPR(anon > 0, "(memory.stat.anon=%zd) > 0", anon);
52	TST_EXP_EXPR(values_close(size, anon, 3),
53		     "(size=%zd) ~= (memory.stat.anon=%zd)", size, anon);
54	TST_EXP_EXPR(values_close(anon, current, 3),
55		     "(memory.current=%zd) ~= (memory.stat.anon=%zd)",
56		     current, anon);
57}
58
59static void alloc_pagecache_50M_check(void)
60{
61	const size_t size = MB(50);
62	size_t current, file;
63	const char *const file_key_fmt =
64		TST_CG_VER_IS_V1(tst_cg, "memory") ? "cache %zd" : "file %zd";
65
66	fd = SAFE_OPEN(TMPDIR"/tmpfile", O_RDWR | O_CREAT, 0600);
67
68	SAFE_CG_SCANF(cg_child, "memory.current", "%zu", &current);
69	tst_res(TINFO, "Created temp file: memory.current=%zu", current);
70
71	alloc_pagecache(fd, size);
72
73	SAFE_CG_SCANF(cg_child, "memory.current", "%zu", &current);
74	TST_EXP_EXPR(current >= size,
75			 "(memory.current=%zu) >= (size=%zu)", current, size);
76
77	SAFE_CG_LINES_SCANF(cg_child, "memory.stat", file_key_fmt, &file);
78	TST_EXP_EXPR(file > 0, "(memory.stat.file=%zd) > 0", file);
79
80	TST_EXP_EXPR(values_close(file, current, file_to_all_error),
81			 "(memory.current=%zd) ~= (memory.stat.file=%zd)",
82			 current, file);
83
84	SAFE_CLOSE(fd);
85}
86
87static void test_memcg_current(unsigned int n)
88{
89	size_t current;
90
91	cg_child = tst_cg_group_mk(tst_cg, "child");
92	SAFE_CG_SCANF(cg_child, "memory.current", "%zu", &current);
93	TST_EXP_EXPR(current == 0, "(current=%zu) == 0", current);
94
95	if (!SAFE_FORK()) {
96		SAFE_CG_PRINTF(cg_child, "cgroup.procs", "%d", getpid());
97
98		SAFE_CG_SCANF(cg_child, "memory.current", "%zu", &current);
99		tst_res(TINFO, "Added proc to memcg: memory.current=%zu",
100			current);
101
102		if (!n)
103			alloc_anon_50M_check();
104		else
105			alloc_pagecache_50M_check();
106	} else {
107		tst_reap_children();
108		cg_child = tst_cg_group_rm(cg_child);
109	}
110}
111
112static void setup(void)
113{
114	page_size = SAFE_SYSCONF(_SC_PAGESIZE);
115
116	switch (tst_fs_type(TMPDIR)) {
117	case TST_VFAT_MAGIC:
118	case TST_EXFAT_MAGIC:
119	case TST_EXT234_MAGIC:
120		file_to_all_error = 50;
121		break;
122	}
123}
124
125static void cleanup(void)
126{
127	if (cg_child)
128		cg_child = tst_cg_group_rm(cg_child);
129}
130
131static struct tst_test test = {
132	.setup = setup,
133	.cleanup = cleanup,
134	.tcnt = 2,
135	.test = test_memcg_current,
136	.mount_device = 1,
137	.dev_min_size = 256,
138	.mntpoint = TMPDIR,
139	.all_filesystems = 1,
140	.forks_child = 1,
141	.needs_root = 1,
142	.needs_cgroup_ctrls = (const char *const []){ "memory", NULL },
143};
144