On Tue, Oct 17, 2023 at 4:21 PM Nhat Pham nphamcs@gmail.com wrote:
From: Domenico Cerasuolo cerasuolodomenico@gmail.com
The memcg-zswap self test is updated to adjust to the behavior change implemented by commit 87730b165089 ("zswap: make shrinking memcg-aware"), where zswap performs writeback for specific memcg.
Signed-off-by: Domenico Cerasuolo cerasuolodomenico@gmail.com Signed-off-by: Nhat Pham nphamcs@gmail.com
/s/Signed-off/Acked This is Domenico's work :) I used the wrong tag here. Should be: Acked-by: Nhat Pham nphamcs@gmail.com
tools/testing/selftests/cgroup/test_zswap.c | 74 ++++++++++++++------- 1 file changed, 50 insertions(+), 24 deletions(-)
diff --git a/tools/testing/selftests/cgroup/test_zswap.c b/tools/testing/selftests/cgroup/test_zswap.c index 49def87a909b..11271fabeffc 100644 --- a/tools/testing/selftests/cgroup/test_zswap.c +++ b/tools/testing/selftests/cgroup/test_zswap.c @@ -50,9 +50,9 @@ static int get_zswap_stored_pages(size_t *value) return read_int("/sys/kernel/debug/zswap/stored_pages", value); }
-static int get_zswap_written_back_pages(size_t *value) +static int get_cg_wb_count(const char *cg) {
return read_int("/sys/kernel/debug/zswap/written_back_pages", value);
return cg_read_key_long(cg, "memory.stat", "zswap_wb");}
static int allocate_bytes(const char *cgroup, void *arg) @@ -68,45 +68,71 @@ static int allocate_bytes(const char *cgroup, void *arg) return 0; }
+static char *setup_test_group_1M(const char *root, const char *name) +{
char *group_name = cg_name(root, name);if (!group_name)return NULL;if (cg_create(group_name))goto fail;if (cg_write(group_name, "memory.max", "1M")) {cg_destroy(group_name);goto fail;}return group_name;+fail:
free(group_name);return NULL;+}
/*
- When trying to store a memcg page in zswap, if the memcg hits its memory
- limit in zswap, writeback should not be triggered.
- This was fixed with commit 0bdf0efa180a("zswap: do not shrink if cgroup may
- not zswap"). Needs to be revised when a per memcg writeback mechanism is
- implemented.
- limit in zswap, writeback should affect only the zswapped pages of that
*/
- memcg.
static int test_no_invasive_cgroup_shrink(const char *root) {
size_t written_back_before, written_back_after; int ret = KSFT_FAIL;char *test_group;
size_t control_allocation_size = MB(10);char *control_allocation, *wb_group = NULL, *control_group = NULL; /* Set up */
test_group = cg_name(root, "no_shrink_test");if (!test_group)goto out;if (cg_create(test_group))
wb_group = setup_test_group_1M(root, "per_memcg_wb_test1");if (!wb_group)return KSFT_FAIL;if (cg_write(wb_group, "memory.zswap.max", "10K")) goto out;
if (cg_write(test_group, "memory.max", "1M"))
control_group = setup_test_group_1M(root, "per_memcg_wb_test2");if (!control_group) goto out;
if (cg_write(test_group, "memory.zswap.max", "10K"))
/* Push some test_group2 memory into zswap */if (cg_enter_current(control_group)) goto out;
if (get_zswap_written_back_pages(&written_back_before))
control_allocation = malloc(control_allocation_size);for (int i = 0; i < control_allocation_size; i += 4095)control_allocation[i] = 'a';if (cg_read_key_long(control_group, "memory.stat", "zswapped") < 1) goto out;
/* Allocate 10x memory.max to push memory into zswap */if (cg_run(test_group, allocate_bytes, (void *)MB(10)))
/* Allocate 10x memory.max to push wb_group memory into zswap and trigger wb */if (cg_run(wb_group, allocate_bytes, (void *)MB(10))) goto out;
/* Verify that no writeback happened because of the memcg allocation */if (get_zswap_written_back_pages(&written_back_after))goto out;if (written_back_after == written_back_before)
/* Verify that only zswapped memory from gwb_group has been written back */if (get_cg_wb_count(wb_group) > 0 && get_cg_wb_count(control_group) == 0) ret = KSFT_PASS;out:
cg_destroy(test_group);free(test_group);
cg_enter_current(root);if (control_group) {cg_destroy(control_group);free(control_group);}cg_destroy(wb_group);free(wb_group);if (control_allocation)free(control_allocation); return ret;}
-- 2.34.1