Add a new test for memory.reclaim that verifies that the interface
correctly reclaims memory as intended, from both anon and file pages.
Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Acked-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
---
.../selftests/cgroup/test_memcontrol.c | 86 +++++++++++++++++++
1 file changed, 86 insertions(+)
diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c
index f2ffb3a30194..5f7c20de2426 100644
--- a/tools/testing/selftests/cgroup/test_memcontrol.c
+++ b/tools/testing/selftests/cgroup/test_memcontrol.c
@@ -760,6 +760,91 @@ static int test_memcg_max(const char *root)
return ret;
}
+/*
+ * This test checks that memory.reclaim reclaims the given
+ * amount of memory (from both anon and file).
+ */
+static int test_memcg_reclaim(const char *root)
+{
+ int ret = KSFT_FAIL, fd, retries;
+ char *memcg;
+ long current, to_reclaim;
+ char buf[64];
+
+ memcg = cg_name(root, "memcg_test");
+ if (!memcg)
+ goto cleanup;
+
+ if (cg_create(memcg))
+ goto cleanup;
+
+ current = cg_read_long(memcg, "memory.current");
+ if (current != 0)
+ goto cleanup;
+
+ cg_run_nowait(memcg, alloc_anon_noexit, (void *) MB(50));
+ sleep(1);
+
+ fd = get_temp_fd();
+ if (fd < 0)
+ goto cleanup;
+
+ cg_run_nowait(memcg, alloc_pagecache_50M_noexit, (void *)(long)fd);
+ sleep(1);
+
+ current = cg_read_long(memcg, "memory.current");
+ if (!values_close(current, MB(100), 10))
+ goto cleanup;
+
+ /*
+ * Reclaim until current reaches 30M, make sure to reclaim over 50M to
+ * hit both anon and file.
+ */
+ retries = 5;
+ while (true) {
+ int err;
+
+ current = cg_read_long(memcg, "memory.current");
+ to_reclaim = current - MB(30);
+
+ /*
+ * We only keep looping if we get EAGAIN, which means we could
+ * not reclaim the full amount.
+ */
+ if (to_reclaim <= 0)
+ goto cleanup;
+
+
+ snprintf(buf, sizeof(buf), "%ld", to_reclaim);
+ err = cg_write(memcg, "memory.reclaim", buf);
+ if (!err) {
+ /*
+ * If writing succeeds, then the written amount should have been
+ * fully reclaimed (and maybe more).
+ */
+ current = cg_read_long(memcg, "memory.current");
+ if (!values_close(current, MB(30), 3) && current > MB(30))
+ goto cleanup;
+ break;
+ }
+
+ /* The kernel could not reclaim the full amount, try again. */
+ if (err == -EAGAIN && retries--)
+ continue;
+
+ /* We got an unexpected error or ran out of retries. */
+ goto cleanup;
+ }
+
+ ret = KSFT_PASS;
+cleanup:
+ cg_destroy(memcg);
+ free(memcg);
+ close(fd);
+
+ return ret;
+}
+
static int alloc_anon_50M_check_swap(const char *cgroup, void *arg)
{
long mem_max = (long)arg;
@@ -1263,6 +1348,7 @@ struct memcg_test {
T(test_memcg_high),
T(test_memcg_high_sync),
T(test_memcg_max),
+ T(test_memcg_reclaim),
T(test_memcg_oom_events),
T(test_memcg_swap_max),
T(test_memcg_sock),
--
2.36.0.rc2.479.g8af0fa9b8e-goog
