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authorDavid Vernet <void@manifault.com>2022-05-12 20:22:57 -0700
committerAndrew Morton <akpm@linux-foundation.org>2022-05-13 07:20:12 -0700
commitcdc69458a5f3d4cf31372efd45fe92cec6b167e4 (patch)
tree6156a64cffc2c648dc67990b1759ba95563a37ae /tools
parentcgroups: refactor children cgroups in memcg tests (diff)
downloadlinux-dev-cdc69458a5f3d4cf31372efd45fe92cec6b167e4.tar.xz
linux-dev-cdc69458a5f3d4cf31372efd45fe92cec6b167e4.zip
cgroup: account for memory_recursiveprot in test_memcg_low()
The test_memcg_low() testcase in test_memcontrol.c verifies the expected behavior of groups using the memory.low knob. Part of the testcase verifies that a group with memory.low that experiences reclaim due to memory pressure elsewhere in the system, observes memory.events.low events as a result of that reclaim. In commit 8a931f801340 ("mm: memcontrol: recursive memory.low protection"), the memory controller was updated to propagate memory.low and memory.min protection from a parent group to its children via a configurable memory_recursiveprot mount option. This unfortunately broke the memcg tests, which asserts that a sibling that experienced reclaim but had a memory.low value of 0, would not observe any memory.low events. This patch updates test_memcg_low() to account for the new behavior introduced by memory_recursiveprot. So as to make the test resilient to multiple configurations, the patch also adds a new proc_mount_contains() helper that checks for a string in /proc/mounts, and is used to toggle behavior based on whether the default memory_recursiveprot was present. Link: https://lkml.kernel.org/r/20220423155619.3669555-3-void@manifault.com Signed-off-by: David Vernet <void@manifault.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'tools')
-rw-r--r--tools/testing/selftests/cgroup/cgroup_util.c12
-rw-r--r--tools/testing/selftests/cgroup/cgroup_util.h1
-rw-r--r--tools/testing/selftests/cgroup/test_memcontrol.c16
3 files changed, 26 insertions, 3 deletions
diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/cgroup_util.c
index e6f3679cdcc0..b4d7027a44c3 100644
--- a/tools/testing/selftests/cgroup/cgroup_util.c
+++ b/tools/testing/selftests/cgroup/cgroup_util.c
@@ -528,6 +528,18 @@ int set_oom_adj_score(int pid, int score)
return 0;
}
+int proc_mount_contains(const char *option)
+{
+ char buf[4 * PAGE_SIZE];
+ ssize_t read;
+
+ read = read_text("/proc/mounts", buf, sizeof(buf));
+ if (read < 0)
+ return read;
+
+ return strstr(buf, option) != NULL;
+}
+
ssize_t proc_read_text(int pid, bool thread, const char *item, char *buf, size_t size)
{
char path[PATH_MAX];
diff --git a/tools/testing/selftests/cgroup/cgroup_util.h b/tools/testing/selftests/cgroup/cgroup_util.h
index 628738532ac9..756f76052b44 100644
--- a/tools/testing/selftests/cgroup/cgroup_util.h
+++ b/tools/testing/selftests/cgroup/cgroup_util.h
@@ -48,6 +48,7 @@ extern int is_swap_enabled(void);
extern int set_oom_adj_score(int pid, int score);
extern int cg_wait_for_proc_count(const char *cgroup, int count);
extern int cg_killall(const char *cgroup);
+int proc_mount_contains(const char *option);
extern ssize_t proc_read_text(int pid, bool thread, const char *item, char *buf, size_t size);
extern int proc_read_strstr(int pid, bool thread, const char *item, const char *needle);
extern pid_t clone_into_cgroup(int cgroup_fd);
diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c
index d240a391f99e..4da138d05acb 100644
--- a/tools/testing/selftests/cgroup/test_memcontrol.c
+++ b/tools/testing/selftests/cgroup/test_memcontrol.c
@@ -21,6 +21,8 @@
#include "../kselftest.h"
#include "cgroup_util.h"
+static bool has_recursiveprot;
+
/*
* This test creates two nested cgroups with and without enabling
* the memory controller.
@@ -525,15 +527,18 @@ static int test_memcg_low(const char *root)
}
for (i = 0; i < ARRAY_SIZE(children); i++) {
+ int no_low_events_index = has_recursiveprot ? 2 : 1;
+
oom = cg_read_key_long(children[i], "memory.events", "oom ");
low = cg_read_key_long(children[i], "memory.events", "low ");
if (oom)
goto cleanup;
- if (i < 2 && low <= 0)
+ if (i <= no_low_events_index && low <= 0)
goto cleanup;
- if (i >= 2 && low)
+ if (i > no_low_events_index && low)
goto cleanup;
+
}
ret = KSFT_PASS;
@@ -1382,7 +1387,7 @@ struct memcg_test {
int main(int argc, char **argv)
{
char root[PATH_MAX];
- int i, ret = EXIT_SUCCESS;
+ int i, proc_status, ret = EXIT_SUCCESS;
if (cg_find_unified_root(root, sizeof(root)))
ksft_exit_skip("cgroup v2 isn't mounted\n");
@@ -1398,6 +1403,11 @@ int main(int argc, char **argv)
if (cg_write(root, "cgroup.subtree_control", "+memory"))
ksft_exit_skip("Failed to set memory controller\n");
+ proc_status = proc_mount_contains("memory_recursiveprot");
+ if (proc_status < 0)
+ ksft_exit_skip("Failed to query cgroup mount option\n");
+ has_recursiveprot = proc_status;
+
for (i = 0; i < ARRAY_SIZE(tests); i++) {
switch (tests[i].fn(root)) {
case KSFT_PASS: