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author | Yosry Ahmed <yosryahmed@google.com> | 2022-04-29 14:37:00 -0700 |
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committer | akpm <akpm@linux-foundation.org> | 2022-04-29 14:37:00 -0700 |
commit | eae3cb2e87ff84547e66211b81301a8f9122840f (patch) | |
tree | fb7d937af237326df76a10aee67ed22bac1de507 /tools | |
parent | a3622a53e620700053b648478dbc638ad373be3b (diff) | |
download | linux-eae3cb2e87ff84547e66211b81301a8f9122840f.tar.gz linux-eae3cb2e87ff84547e66211b81301a8f9122840f.tar.bz2 linux-eae3cb2e87ff84547e66211b81301a8f9122840f.zip |
selftests: cgroup: add a selftest for memory.reclaim
Add a new test for memory.reclaim that verifies that the interface
correctly reclaims memory as intended, from both anon and file pages.
Link: https://lkml.kernel.org/r/20220425190040.2475377-5-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Chen Wandun <chenwandun@huawei.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Michal Koutn" <mkoutny@suse.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vaibhav Jain <vaibhav@linux.ibm.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'tools')
-rw-r--r-- | tools/testing/selftests/cgroup/test_memcontrol.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c index a639bf49d396..ee7defb17280 100644 --- a/tools/testing/selftests/cgroup/test_memcontrol.c +++ b/tools/testing/selftests/cgroup/test_memcontrol.c @@ -760,6 +760,111 @@ cleanup: return ret; } +/* + * This test checks that memory.reclaim reclaims the given + * amount of memory (from both anon and file, if possible). + */ +static int test_memcg_reclaim(const char *root) +{ + int ret = KSFT_FAIL, fd, retries; + char *memcg; + long current, expected_usage, 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; + + fd = get_temp_fd(); + if (fd < 0) + goto cleanup; + + cg_run_nowait(memcg, alloc_pagecache_50M_noexit, (void *)(long)fd); + + /* + * If swap is enabled, try to reclaim from both anon and file, else try + * to reclaim from file only. + */ + if (is_swap_enabled()) { + cg_run_nowait(memcg, alloc_anon_noexit, (void *) MB(50)); + expected_usage = MB(100); + } else + expected_usage = MB(50); + + /* + * Wait until current usage reaches the expected usage (or we run out of + * retries). + */ + retries = 5; + while (!values_close(cg_read_long(memcg, "memory.current"), + expected_usage, 10)) { + if (retries--) { + sleep(1); + continue; + } else { + fprintf(stderr, + "failed to allocate %ld for memcg reclaim test\n", + expected_usage); + goto cleanup; + } + } + + /* + * Reclaim until current reaches 30M, this makes sure we hit both anon + * and file if swap is enabled. + */ + 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; @@ -1264,6 +1369,7 @@ 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), |