Messages in this thread Patch in this message | | | From | Roman Gushchin <> | Subject | [PATCH] selftests: cgroup: add test for memory.low corner cases | Date | Tue, 22 May 2018 14:31:06 +0100 |
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Add a more complicated test for memory.low hierarchical behavior. It creates the following hierarchy: A memory.low = 50M B memory.low = 50M C memory.low = 50M D memory.low = 50M memory.(swap.)max = 200M E memory.low = 50M / \ F' F memory.low = 50M G memory.low = 50M H memory.low = 50M I memory.low = 50M J memory.low = 50M K memory.low = 50M, memory.usage = 50M
First, it creates local memory pressure by charging pagecache to F' and checks that K's memory.low actually works (usage ~= 50M). The it sets C's memory.low to 0 and repeats the test to check that K's memory.low is not working anymore, despite that memory.low is disabled above the cgroup with memory pressure (D).
Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Greg Thelen <gthelen@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> --- tools/testing/selftests/cgroup/test_memcontrol.c | 115 +++++++++++++++++++++++ 1 file changed, 115 insertions(+)
diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c index beae06c9c899..45168a845a5d 100644 --- a/tools/testing/selftests/cgroup/test_memcontrol.c +++ b/tools/testing/selftests/cgroup/test_memcontrol.c @@ -512,6 +512,120 @@ static int test_memcg_low(const char *root) return ret; } +static int alloc_pagecache_500M(const char *cgroup, void *arg) +{ + int fd = (long)arg; + + return alloc_pagecache(fd, MB(500)); +} + +/* + * The test creates 10 nested memory cgroups with memory.min set to 50M, + * with 50M of pagecache charget to the leaf cgroup. + * Then it sets memory.max and memory.swap.max to 200M on the 3rd level, + * and creates memory pressure on 5th level. + * First it checks that memory.low actually works: + * expected usage on 9th level is 50M. + * Then it set memory.low on 2nd level to 0 and checks + * that memory.low stopped working: + * expected usage on 9th level is < 20M. + */ +static int test_memcg_low_nested(const char *root) +{ + int ret = KSFT_FAIL; + char *cgroup[10] = {NULL}; + char *cgroup2; + long usage; + int i, fd; + + fd = get_temp_fd(); + if (fd < 0) + goto cleanup; + + for (i = 0; i < ARRAY_SIZE(cgroup); i++) { + cgroup[i] = cg_name_indexed(i ? cgroup[i - 1] : root, "cg", i); + if (!cgroup[i]) + goto cleanup; + + if (cg_create(cgroup[i])) + goto cleanup; + + if (i < ARRAY_SIZE(cgroup) - 1) + if (cg_write(cgroup[i], "cgroup.subtree_control", + "+memory")) + goto cleanup; + + if (i == 3) { + if (cg_write(cgroup[i], "memory.max", "200M")) + goto cleanup; + + if (cg_write(cgroup[i], "memory.swap.max", "0")) + goto cleanup; + } + + if (cg_write(cgroup[i], "memory.low", "50M")) + goto cleanup; + } + + cgroup2 = cg_name(cgroup[5], "memcg_pressure"); + if (!cgroup2) + goto cleanup; + + if (cg_create(cgroup2)) + goto cleanup; + + /* Part 1 */ + if (cg_run(cgroup[ARRAY_SIZE(cgroup) - 1], alloc_pagecache_50M, + (void *)(long)fd)) + goto cleanup; + + if (cg_run(cgroup2, alloc_pagecache_500M, (void *)(long)fd)) + goto cleanup; + + if (!values_close(cg_read_long(cgroup[ARRAY_SIZE(cgroup) - 1], + "memory.current"), MB(50), 3)) + goto cleanup; + + close(fd); + fd = get_temp_fd(); + if (fd < 0) + goto cleanup; + + /* Part 2 */ + if (cg_write(cgroup[2], "memory.low", "0")) + goto cleanup; + + if (cg_run(cgroup[ARRAY_SIZE(cgroup) - 1], alloc_pagecache_50M, + (void *)(long)fd)) + goto cleanup; + + if (cg_run(cgroup2, alloc_pagecache_500M, (void *)(long)fd)) + goto cleanup; + + usage = cg_read_long(cgroup[ARRAY_SIZE(cgroup) - 1], "memory.current"); + if (usage > MB(20)) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + if (cgroup2) { + cg_destroy(cgroup2); + free(cgroup2); + } + + for (i = ARRAY_SIZE(cgroup) - 1; i >= 0; i--) { + if (!cgroup[i]) + continue; + + cg_destroy(cgroup[i]); + free(cgroup[i]); + } + + close(fd); + return ret; +} + static int alloc_pagecache_max_30M(const char *cgroup, void *arg) { size_t size = MB(50); @@ -781,6 +895,7 @@ struct memcg_test { T(test_memcg_current), T(test_memcg_min), T(test_memcg_low), + T(test_memcg_low_nested), T(test_memcg_high), T(test_memcg_max), T(test_memcg_oom_events), -- 2.14.3
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