[PATCH 4.18 079/135] Add tests for memory.oom.group

Greg Kroah-Hartman
2018-10-16T17:16:14Z

From: Jay Kamat <jgkamat@fb.com>

[ Upstream commit a987785dcd6c8ae2915460582aebd6481c81eb67 ]

Add tests for memory.oom.group for the following cases:
- Killing all processes in a leaf cgroup, but leaving the
parent untouched
- Killing all processes in a parent and leaf cgroup
- Keeping processes marked by OOM_SCORE_ADJ_MIN alive when considered
for being killed by the group oom killer.

Signed-off-by: Jay Kamat <jgkamat@fb.com>
Acked-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/testing/selftests/cgroup/cgroup_util.c | 21 ++
tools/testing/selftests/cgroup/cgroup_util.h | 1
tools/testing/selftests/cgroup/test_memcontrol.c | 205 +++++++++++++++++++++++
3 files changed, 227 insertions(+)

--- a/tools/testing/selftests/cgroup/cgroup_util.c
+++ b/tools/testing/selftests/cgroup/cgroup_util.c
@@ -340,3 +340,24 @@ int is_swap_enabled(void)

return cnt > 1;
}
+
+int set_oom_adj_score(int pid, int score)
+{
+ char path[PATH_MAX];
+ int fd, len;
+
+ sprintf(path, "/proc/%d/oom_score_adj", pid);
+
+ fd = open(path, O_WRONLY | O_APPEND);
+ if (fd < 0)
+ return fd;
+
+ len = dprintf(fd, "%d", score);
+ if (len < 0) {
+ close(fd);
+ return len;
+ }
+
+ close(fd);
+ return 0;
+}
--- a/tools/testing/selftests/cgroup/cgroup_util.h
+++ b/tools/testing/selftests/cgroup/cgroup_util.h
@@ -39,3 +39,4 @@ extern int get_temp_fd(void);
extern int alloc_pagecache(int fd, size_t size);
extern int alloc_anon(const char *cgroup, void *arg);
extern int is_swap_enabled(void);
+extern int set_oom_adj_score(int pid, int score);
--- a/tools/testing/selftests/cgroup/test_memcontrol.c
+++ b/tools/testing/selftests/cgroup/test_memcontrol.c
@@ -2,6 +2,7 @@
#define _GNU_SOURCE

#include <linux/limits.h>
+#include <linux/oom.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
@@ -202,6 +203,36 @@ static int alloc_pagecache_50M_noexit(co
return 0;
}

+static int alloc_anon_noexit(const char *cgroup, void *arg)
+{
+ int ppid = getppid();
+
+ if (alloc_anon(cgroup, arg))
+ return -1;
+
+ while (getppid() == ppid)
+ sleep(1);
+
+ return 0;
+}
+
+/*
+ * Wait until processes are killed asynchronously by the OOM killer
+ * If we exceed a timeout, fail.
+ */
+static int cg_test_proc_killed(const char *cgroup)
+{
+ int limit;
+
+ for (limit = 10; limit > 0; limit--) {
+ if (cg_read_strcmp(cgroup, "cgroup.procs", "") == 0)
+ return 0;
+
+ usleep(100000);
+ }
+ return -1;
+}
+
/*
* First, this test creates the following hierarchy:
* A memory.min = 50M, memory.max = 200M
@@ -964,6 +995,177 @@ cleanup:
return ret;
}

+/*
+ * This test disables swapping and tries to allocate anonymous memory
+ * up to OOM with memory.group.oom set. Then it checks that all
+ * processes in the leaf (but not the parent) were killed.
+ */
+static int test_memcg_oom_group_leaf_events(const char *root)
+{
+ int ret = KSFT_FAIL;
+ char *parent, *child;
+
+ parent = cg_name(root, "memcg_test_0");
+ child = cg_name(root, "memcg_test_0/memcg_test_1");
+
+ if (!parent || !child)
+ goto cleanup;
+
+ if (cg_create(parent))
+ goto cleanup;
+
+ if (cg_create(child))
+ goto cleanup;
+
+ if (cg_write(parent, "cgroup.subtree_control", "+memory"))
+ goto cleanup;
+
+ if (cg_write(child, "memory.max", "50M"))
+ goto cleanup;
+
+ if (cg_write(child, "memory.swap.max", "0"))
+ goto cleanup;
+
+ if (cg_write(child, "memory.oom.group", "1"))
+ goto cleanup;
+
+ cg_run_nowait(parent, alloc_anon_noexit, (void *) MB(60));
+ cg_run_nowait(child, alloc_anon_noexit, (void *) MB(1));
+ cg_run_nowait(child, alloc_anon_noexit, (void *) MB(1));
+ if (!cg_run(child, alloc_anon, (void *)MB(100)))
+ goto cleanup;
+
+ if (cg_test_proc_killed(child))
+ goto cleanup;
+
+ if (cg_read_key_long(child, "memory.events", "oom_kill ") <= 0)
+ goto cleanup;
+
+ if (cg_read_key_long(parent, "memory.events", "oom_kill ") != 0)
+ goto cleanup;
+
+ ret = KSFT_PASS;
+
+cleanup:
+ if (child)
+ cg_destroy(child);
+ if (parent)
+ cg_destroy(parent);
+ free(child);
+ free(parent);
+
+ return ret;
+}
+
+/*
+ * This test disables swapping and tries to allocate anonymous memory
+ * up to OOM with memory.group.oom set. Then it checks that all
+ * processes in the parent and leaf were killed.
+ */
+static int test_memcg_oom_group_parent_events(const char *root)
+{
+ int ret = KSFT_FAIL;
+ char *parent, *child;
+
+ parent = cg_name(root, "memcg_test_0");
+ child = cg_name(root, "memcg_test_0/memcg_test_1");
+
+ if (!parent || !child)
+ goto cleanup;
+
+ if (cg_create(parent))
+ goto cleanup;
+
+ if (cg_create(child))
+ goto cleanup;
+
+ if (cg_write(parent, "memory.max", "80M"))
+ goto cleanup;
+
+ if (cg_write(parent, "memory.swap.max", "0"))
+ goto cleanup;
+
+ if (cg_write(parent, "memory.oom.group", "1"))
+ goto cleanup;
+
+ cg_run_nowait(parent, alloc_anon_noexit, (void *) MB(60));
+ cg_run_nowait(child, alloc_anon_noexit, (void *) MB(1));
+ cg_run_nowait(child, alloc_anon_noexit, (void *) MB(1));
+
+ if (!cg_run(child, alloc_anon, (void *)MB(100)))
+ goto cleanup;
+
+ if (cg_test_proc_killed(child))
+ goto cleanup;
+ if (cg_test_proc_killed(parent))
+ goto cleanup;
+
+ ret = KSFT_PASS;
+
+cleanup:
+ if (child)
+ cg_destroy(child);
+ if (parent)
+ cg_destroy(parent);
+ free(child);
+ free(parent);
+
+ return ret;
+}
+
+/*
+ * This test disables swapping and tries to allocate anonymous memory
+ * up to OOM with memory.group.oom set. Then it checks that all
+ * processes were killed except those set with OOM_SCORE_ADJ_MIN
+ */
+static int test_memcg_oom_group_score_events(const char *root)
+{
+ int ret = KSFT_FAIL;
+ char *memcg;
+ int safe_pid;
+
+ memcg = cg_name(root, "memcg_test_0");
+
+ if (!memcg)
+ goto cleanup;
+
+ if (cg_create(memcg))
+ goto cleanup;
+
+ if (cg_write(memcg, "memory.max", "50M"))
+ goto cleanup;
+
+ if (cg_write(memcg, "memory.swap.max", "0"))
+ goto cleanup;
+
+ if (cg_write(memcg, "memory.oom.group", "1"))
+ goto cleanup;
+
+ safe_pid = cg_run_nowait(memcg, alloc_anon_noexit, (void *) MB(1));
+ if (set_oom_adj_score(safe_pid, OOM_SCORE_ADJ_MIN))
+ goto cleanup;
+
+ cg_run_nowait(memcg, alloc_anon_noexit, (void *) MB(1));
+ if (!cg_run(memcg, alloc_anon, (void *)MB(100)))
+ goto cleanup;
+
+ if (cg_read_key_long(memcg, "memory.events", "oom_kill ") != 3)
+ goto cleanup;
+
+ if (kill(safe_pid, SIGKILL))
+ goto cleanup;
+
+ ret = KSFT_PASS;
+
+cleanup:
+ if (memcg)
+ cg_destroy(memcg);
+ free(memcg);
+
+ return ret;
+}
+
+
#define T(x) { x, #x }
struct memcg_test {
int (*fn)(const char *root);
@@ -978,6 +1180,9 @@ struct memcg_test {
T(test_memcg_oom_events),
T(test_memcg_swap_max),
T(test_memcg_sock),
+ T(test_memcg_oom_group_leaf_events),
+ T(test_memcg_oom_group_parent_events),
+ T(test_memcg_oom_group_score_events),
};
#undef T