[LTP] [PATCH] controllers/memcg: update regression tests to work under cgroup2

[Luke Nowakowski-Krijger]

Some tests no longer make sense under cgroup2, while other tests just
needed to be updated to use new parameters introduced by the cgroup2
interface.

Signed-off-by: Luke Nowakowski-Krijger <luke.nowakowskikrijger@canonical.com>
---
 .../memcg/regression/memcg_regression_test.sh | 41 ++++++++++++++++---
 .../memcg/regression/memcg_test_1.c           | 12 +++++-
 .../memcg/regression/memcg_test_3.c           |  8 ++++
 .../memcg/regression/memcg_test_4.sh          | 18 ++++++--
 4 files changed, 68 insertions(+), 11 deletions(-)

diff --git a/testcases/kernel/controllers/memcg/regression/memcg_regression_test.sh b/testcases/kernel/controllers/memcg/regression/memcg_regression_test.sh
index c91a4069e..ad88d49d1 100755
--- a/testcases/kernel/controllers/memcg/regression/memcg_regression_test.sh
+++ b/testcases/kernel/controllers/memcg/regression/memcg_regression_test.sh
@@ -103,7 +103,12 @@ check_kernel_bug()
 test_1()
 {
 	mkdir memcg/0/
-	echo 0 > memcg/0/memory.limit_in_bytes
+
+	if [ "$cgroup_ver" = "cgroup2" ]; then
+		echo 0 > memcg/0/memory.max
+	else
+		echo 0 > memcg/0/memory.limit_in_bytes
+	fi
 
 	./memcg_test_1
 
@@ -124,6 +129,16 @@ test_1()
 #---------------------------------------------------------------------------
 test_2()
 {
+	# for cgroup2 the default behaivor is to check the new memory limit and
+	# then to start killing processes if oom. This test then doesen't
+	# make sense as we don't expect EBUSY to be returned. The shrink
+	# operation (write to memory.max in cgroup2) would kill the pid1 process
+	# and exit.
+	if [ "$cgroup_ver" = "cgroup2" ]; then
+		tst_resm TCONF "cgroup2 found, skipping test"
+		return
+	fi
+
 	./memcg_test_2 &
 	pid1=$!
 	sleep 1
@@ -177,12 +192,20 @@ test_2()
 test_3()
 {
 	mkdir memcg/0
-	for pid in `cat memcg/tasks`; do
-		echo $pid > memcg/0/tasks 2> /dev/null
+	if [ "$cgroup_ver" = "cgroup2" ]; then
+		memcg_procs=memcg/cgroup.procs
+		memcg_subprocs=memcg/0/cgroup.procs
+	else
+		memcg_procs=memcg/tasks
+		memcg_subprocs=memcg/0/tasks
+	fi
+
+	for pid in `cat $memcg_procs`; do
+		echo $pid > $memcg_subprocs 2> /dev/null
 	done
 
-	for pid in `cat memcg/0/tasks`; do
-		echo $pid > memcg/tasks 2> /dev/null
+	for pid in `cat $memcg_subprocs`; do
+		echo $pid > $memcg_procs 2> /dev/null
 	done
 	rmdir memcg/0
 
@@ -218,13 +241,19 @@ test_4()
 }
 
 # main
+cgroup_ver=$(grep "/sys/fs/cgroup" /proc/mounts | cut -d' ' -f1)
 failed=0
 mkdir memcg/
 
 for cur in $(seq 1 $TST_TOTAL); do
 	export TST_COUNT=$cur
 
-	mount -t cgroup -o memory xxx memcg/
+	if [ "$cgroup_ver" = "cgroup2" ]; then
+		mount -t cgroup2 xxx memcg/
+	else
+		mount -t cgroup -o memory xxx memcg/
+	fi
+
 	if [ $? -ne 0 ]; then
 		tst_resm TFAIL "failed to mount memory subsystem"
 		failed=1
diff --git a/testcases/kernel/controllers/memcg/regression/memcg_test_1.c b/testcases/kernel/controllers/memcg/regression/memcg_test_1.c
index c7fb948fe..b9277e633 100644
--- a/testcases/kernel/controllers/memcg/regression/memcg_test_1.c
+++ b/testcases/kernel/controllers/memcg/regression/memcg_test_1.c
@@ -33,6 +33,16 @@
 
 #define FORKED_PROC_COUNT	10
 
+static int open_cgroup_procs(void)
+{
+	int fd = open("memcg/0/tasks", O_WRONLY);
+	if (fd >= 0)
+		return fd;
+
+	fd = open("memcg/0/cgroup.procs", O_WRONLY);
+	return fd;
+}
+
 int main(void)
 {
 	char buf[10];
@@ -40,7 +50,7 @@ int main(void)
 	int loop;
 	int pid;
 	int size = getpagesize();
-	int fd = open("memcg/0/tasks", O_WRONLY);
+	int fd = open_cgroup_procs();
 
 	if (fd < 0)
 		return 1;
diff --git a/testcases/kernel/controllers/memcg/regression/memcg_test_3.c b/testcases/kernel/controllers/memcg/regression/memcg_test_3.c
index 75a6e1545..d5531fe87 100644
--- a/testcases/kernel/controllers/memcg/regression/memcg_test_3.c
+++ b/testcases/kernel/controllers/memcg/regression/memcg_test_3.c
@@ -66,6 +66,14 @@ static void setup(void)
 	SAFE_MKDIR(MNTPOINT, 0644);
 
 	ret = mount("memcg", MNTPOINT, "cgroup", 0, "memory");
+
+	if (!ret) {
+		mount_flag = 1;
+		return;
+	}
+
+	ret = mount("memcg", MNTPOINT, "cgroup2", 0, NULL);
+
 	if (ret) {
 		if (errno == ENOENT)
 			tst_brk(TCONF | TERRNO, "memcg not supported");
diff --git a/testcases/kernel/controllers/memcg/regression/memcg_test_4.sh b/testcases/kernel/controllers/memcg/regression/memcg_test_4.sh
index 620031366..287864b81 100755
--- a/testcases/kernel/controllers/memcg/regression/memcg_test_4.sh
+++ b/testcases/kernel/controllers/memcg/regression/memcg_test_4.sh
@@ -22,9 +22,19 @@
 ##                                                                            ##
 ################################################################################
 
+cgroup_ver=$(grep "/sys/fs/cgroup" /proc/mounts | cut -d' ' -f1)
+
+if [ "$cgroup_ver" = 'cgroup2' ]; then
+	cgroup_proc=cgroup.procs
+	cgroup_mem_limit=memory.max
+else
+	cgroup_proc=tasks
+	cgroup_mem_limit=memory.limit_in_bytes
+fi
+
 # attach current task to memcg/0/
 mkdir memcg/0
-echo $$ > memcg/0/tasks
+echo $$ > memcg/0/${cgroup_proc}
 
 ./memcg_test_4 &
 pid=$!
@@ -35,13 +45,13 @@ sleep 1
 sleep 1
 
 # shrink memory, and then 80M will be swapped
-echo 40M > memcg/0/memory.limit_in_bytes
+echo 40M > memcg/0/${cgroup_mem_limit}
 
 # turn off swap, and swapoff will be killed
 swapoff -a
 sleep 1
-echo $pid > memcg/tasks 2> /dev/null
-echo $$ > memcg/tasks 2> /dev/null
+echo $pid > memcg/${cgroup_proc} 2> /dev/null
+echo $$ > memcg/${cgroup_proc} 2> /dev/null
 
 # now remove the cgroup
 rmdir memcg/0
-- 
2.32.0