diff options
| author | Wilson Felipe Pereira <wfelipe@google.com> | 2026-08-11 05:14:11 +0000 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-08-24 18:43:21 -0700 |
| commit | 6f615890b84820c2e223bd14238319f0415eae88 (patch) | |
| tree | 42e5f14d2de737f5fee580bffbfc66dcee2a6998 /tools | |
| parent | bd1ad3cf07d11fbf203ac362222807113321dfbb (diff) | |
selftests/cgroup: test_zswap: skip test_no_kmem_bypass if debugfs is unavailable
test_no_kmem_bypass() needs to read /sys/kernel/debug/zswap/stored_pages
via get_zswap_stored_pages() to verify that compressed pages are charged
to the memcg.
When running in an environment where debugfs is not mounted or
CONFIG_DEBUG_FS is disabled, get_zswap_stored_pages() fails, causing the
loop to terminate early and report a false negative (KSFT_FAIL).
Selftests should not fail if debugfs is unavailable, and it should print a
message when it is skipped.
While I'm here, also add a warning message if the test is being skipped
due to totalram size and make the check for totalram more readable.
[akpm@linux-foundation.org: clarify debugfs-unavailable error message]
Link: https://lore.kernel.org/20260812050848.848882-1-wfelipe@google.com
Link: https://lore.kernel.org/20260811051434.3805648-1-wfelipe@google.com
Signed-off-by: Wilson Felipe Pereira <wfelipe@google.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
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/lib/include/cgroup_util.h | 1 | ||||
| -rw-r--r-- | tools/testing/selftests/cgroup/test_zswap.c | 13 |
2 files changed, 12 insertions, 2 deletions
diff --git a/tools/testing/selftests/cgroup/lib/include/cgroup_util.h b/tools/testing/selftests/cgroup/lib/include/cgroup_util.h index febc1723d090..c0f07226b222 100644 --- a/tools/testing/selftests/cgroup/lib/include/cgroup_util.h +++ b/tools/testing/selftests/cgroup/lib/include/cgroup_util.h @@ -7,6 +7,7 @@ #endif #define MB(x) (x << 20) +#define GB(x) ((unsigned long long)(x) << 30) #define USEC_PER_SEC 1000000L #define NSEC_PER_SEC 1000000000L diff --git a/tools/testing/selftests/cgroup/test_zswap.c b/tools/testing/selftests/cgroup/test_zswap.c index 49b36ee79160..f7b4c4370db6 100644 --- a/tools/testing/selftests/cgroup/test_zswap.c +++ b/tools/testing/selftests/cgroup/test_zswap.c @@ -20,6 +20,7 @@ static int page_size; #define PATH_ZSWAP "/sys/module/zswap" #define PATH_ZSWAP_ENABLED "/sys/module/zswap/parameters/enabled" +#define PATH_ZSWAP_STORED_PAGES "/sys/kernel/debug/zswap/stored_pages" static int read_int(const char *path, size_t *value) { @@ -55,7 +56,7 @@ static int read_min_free_kb(size_t *value) static int get_zswap_stored_pages(size_t *value) { - return read_int("/sys/kernel/debug/zswap/stored_pages", value); + return read_int(PATH_ZSWAP_STORED_PAGES, value); } static long get_cg_wb_count(const char *cg) @@ -570,8 +571,16 @@ static int test_no_kmem_bypass(const char *root) /* Read sys info and compute test values accordingly */ if (sysinfo(&sys_info) != 0) return KSFT_FAIL; - if (sys_info.totalram > 5000000000) + if (sys_info.totalram > GB(4)) { + ksft_print_msg( + "requires less than 4GB total ram, sys_info.totalram: %.1fGB\n", + (double)sys_info.totalram / GB(1)); return KSFT_SKIP; + } + if (access(PATH_ZSWAP_STORED_PAGES, R_OK)) { + ksft_print_msg("debugfs not mounted at /sys/kernel/debug\n"); + return KSFT_SKIP; + } values = mmap(0, sizeof(struct no_kmem_bypass_child_args), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0); if (values == MAP_FAILED) |