[LTP] [PATCH 3/3] cgroup: Add memcontrol02

[Richard Palethorpe]

Conversion of the second kself test.

Signed-off-by: Richard Palethorpe <rpalethorpe@suse.com>
---
 runtest/controllers                           |   1 +
 testcases/kernel/controllers/memcg/.gitignore |   1 +
 .../kernel/controllers/memcg/memcontrol02.c   | 151 ++++++++++++++++++
 3 files changed, 153 insertions(+)
 create mode 100644 testcases/kernel/controllers/memcg/memcontrol02.c

diff --git a/runtest/controllers b/runtest/controllers
index 2b41a94d3..09e0107e4 100644
--- a/runtest/controllers
+++ b/runtest/controllers
@@ -18,6 +18,7 @@ memcg_control		memcg_control_test.sh
 
 # kselftest ports
 memcontrol01 memcontrol01
+memcontrol02 memcontrol02
 
 cgroup_fj_function_debug cgroup_fj_function.sh debug
 cgroup_fj_function_cpuset cgroup_fj_function.sh cpuset
diff --git a/testcases/kernel/controllers/memcg/.gitignore b/testcases/kernel/controllers/memcg/.gitignore
index c3565f85c..f7de40d53 100644
--- a/testcases/kernel/controllers/memcg/.gitignore
+++ b/testcases/kernel/controllers/memcg/.gitignore
@@ -6,3 +6,4 @@
 /regression/memcg_test_4
 /stress/memcg_process_stress
 memcontrol01
+memcontrol02
diff --git a/testcases/kernel/controllers/memcg/memcontrol02.c b/testcases/kernel/controllers/memcg/memcontrol02.c
new file mode 100644
index 000000000..002637db0
--- /dev/null
+++ b/testcases/kernel/controllers/memcg/memcontrol02.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0
+/*\
+ *
+ * [Description]
+ *
+ * Conversion of second kself test in cgroup/test_memcontrol.c.
+ *
+ * This test creates a memory cgroup, allocates some anonymous memory
+ * and some pagecache and check memory.current and some memory.stat
+ * values.
+ *
+ * Note that the V1 rss and cache counters were renamed to anon and
+ * file in V2. Besides error reporting, this test mainly differs from
+ * the kselftest in that it supports V1.
+ */
+#define _GNU_SOURCE
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "tst_test.h"
+#include "tst_cgroup.h"
+
+#define MB(x) (x << 20)
+
+static size_t page_size;
+static const struct tst_cgroup_group *cg_test;
+static int is_v1_memcg;
+static struct tst_cgroup_group *cg_child;
+static int fd;
+
+/*
+ * Checks if two given values differ by less than err% of their sum.
+ */
+static inline int values_close(const ssize_t a,
+			       const ssize_t b,
+			       const ssize_t err)
+{
+	return labs(a - b) <= (a + b) / 100 * err;
+}
+
+static void alloc_anon_50M_check(void)
+{
+	const ssize_t size = MB(50);
+	char *buf, *ptr;
+	ssize_t anon, current;
+	const char *const anon_key_fmt = is_v1_memcg ? "rss %zd" : "anon %zd";
+
+	buf = SAFE_MALLOC(size);
+	for (ptr = buf; ptr < buf + size; ptr += page_size)
+		*ptr = 0;
+
+	SAFE_CGROUP_SCANF(cg_child, "memory.current", "%zd", &current);
+	TST_EXP_POSITIVE(current >= size,
+			 "(memory.current=%zd) >= (size=%zd)", current, size);
+
+	SAFE_CGROUP_LINES_SCANF(cg_child, "memory.stat", anon_key_fmt, &anon);
+
+	TST_EXP_POSITIVE(anon > 0, "(memory.stat.anon=%zd) > 0", anon);
+
+	TST_EXP_POSITIVE(values_close(size, current, 3),
+			 "(size=%zd) ~= (memory.stat.anon=%zd)", size, current);
+	TST_EXP_POSITIVE(values_close(anon, current, 3),
+			 "(memory.current=%zd) ~= (memory.stat.anon=%zd)",
+			 current, anon);
+}
+
+static void alloc_pagecache(const int fd, size_t size)
+{
+	char buf[BUFSIZ];
+	struct stat st;
+	size_t i;
+
+	SAFE_FSTAT(fd, &st);
+	size += st.st_size;
+
+	SAFE_FTRUNCATE(fd, size);
+
+	for (i = 0; i < size; i += sizeof(buf))
+		SAFE_READ(0, fd, buf, sizeof(buf));
+}
+
+static void alloc_pagecache_50M_check(void)
+{
+	const size_t size = MB(50);
+	size_t current, file;
+	const char *const file_key_fmt = is_v1_memcg ? "cache %zd" : "file %zd";
+
+	fd = SAFE_OPEN("page_cache", O_RDWR | O_CREAT);
+	alloc_pagecache(fd, size);
+
+	SAFE_CGROUP_SCANF(cg_child, "memory.current", "%zu", &current);
+	TST_EXP_POSITIVE(current >= size,
+			 "(memory.current=%zu) >= (size=%zu)", current, size);
+
+	SAFE_CGROUP_LINES_SCANF(cg_child, "memory.stat", file_key_fmt, &file);
+	TST_EXP_POSITIVE(file > 0, "(memory.stat.file=%zd) > 0", file);
+
+	TST_EXP_POSITIVE(values_close(file, current, 10),
+			 "(memory.current=%zd) ~= (memory.stat.file=%zd)",
+			 current, file);
+
+	SAFE_CLOSE(fd);
+}
+
+static void test_memcg_current(unsigned int n)
+{
+	size_t current;
+
+	cg_child = tst_cgroup_group_mk(cg_test, "child");
+	SAFE_CGROUP_SCANF(cg_child, "memory.current", "%zu", &current);
+	TST_EXP_POSITIVE(current == 0, "(current=%zu) == 0", current);
+
+	if (!SAFE_FORK()) {
+		SAFE_CGROUP_PRINTF(cg_child, "cgroup.procs", "%d", getpid());
+		if (!n)
+			alloc_anon_50M_check();
+		else
+			alloc_pagecache_50M_check();
+	} else {
+		tst_reap_children();
+		cg_child = tst_cgroup_group_rm(cg_child);
+	}
+}
+
+static void setup(void)
+{
+	page_size = SAFE_SYSCONF(_SC_PAGESIZE);
+
+	tst_cgroup_require("memory", NULL);
+	cg_test = tst_cgroup_get_test_group();
+
+	is_v1_memcg = TST_CGROUP_VER(cg_test, "memory") == TST_CGROUP_V1;
+}
+
+static void cleanup(void)
+{
+	if (cg_child)
+		cg_child = tst_cgroup_group_rm(cg_child);
+
+	tst_cgroup_cleanup();
+}
+
+static struct tst_test test = {
+	.setup = setup,
+	.cleanup = cleanup,
+	.tcnt = 2,
+	.test = test_memcg_current,
+	.needs_tmpdir = 1,
+	.forks_child = 1,
+};
-- 
2.34.0