Replace destruction paths with simple returns before the test cgroup is
created, there is nothing to free or destroy at that point.
Remove pointless check, stored_pages is a size_t and cannot be < 0.
Fixes: a549f9f31561 ("selftests: cgroup: add test_zswap with no kmem bypass test")
Reported-by: Dan Carpenter <[email protected]>
Signed-off-by: Domenico Cerasuolo <[email protected]>
---
tools/testing/selftests/cgroup/test_zswap.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/cgroup/test_zswap.c b/tools/testing/selftests/cgroup/test_zswap.c
index 49def87a909b..5257106776d5 100644
--- a/tools/testing/selftests/cgroup/test_zswap.c
+++ b/tools/testing/selftests/cgroup/test_zswap.c
@@ -178,10 +178,10 @@ static int test_no_kmem_bypass(const char *root)
/* Set up test memcg */
if (cg_write(root, "cgroup.subtree_control", "+memory"))
- goto out;
+ return KSFT_FAIL;
test_group = cg_name(root, "kmem_bypass_test");
if (!test_group)
- goto out;
+ return KSFT_FAIL;
/* Spawn memcg child and wait for it to allocate */
set_min_free_kb(min_free_kb_low);
@@ -208,8 +208,6 @@ static int test_no_kmem_bypass(const char *root)
free(trigger_allocation);
if (get_zswap_stored_pages(&stored_pages))
break;
- if (stored_pages < 0)
- break;
/* If memory was pushed to zswap, verify it belongs to memcg */
if (stored_pages > stored_pages_threshold) {
int zswapped = cg_read_key_long(test_group, "memory.stat", "zswapped ");
--
2.34.1
On Tue, 12 Sep 2023 10:38:00 +0200 Domenico Cerasuolo <[email protected]> wrote:
> Replace destruction paths with simple returns before the test cgroup is
> created, there is nothing to free or destroy at that point.
>
> Remove pointless check, stored_pages is a size_t and cannot be < 0.
>
> ...
>
> @@ -208,8 +208,6 @@ static int test_no_kmem_bypass(const char *root)
> free(trigger_allocation);
> if (get_zswap_stored_pages(&stored_pages))
> break;
> - if (stored_pages < 0)
> - break;
> /* If memory was pushed to zswap, verify it belongs to memcg */
> if (stored_pages > stored_pages_threshold) {
> int zswapped = cg_read_key_long(test_group, "memory.stat", "zswapped ");
stored_pages will be set to -1 on error. It would be better to cast
stored_pages to ssize_t in the check, rather than simply ignoring
errors?
On Tue, Sep 12, 2023 at 7:18 PM Andrew Morton <[email protected]> wrote:
>
> On Tue, 12 Sep 2023 10:38:00 +0200 Domenico Cerasuolo <[email protected]> wrote:
>
> > Replace destruction paths with simple returns before the test cgroup is
> > created, there is nothing to free or destroy at that point.
> >
> > Remove pointless check, stored_pages is a size_t and cannot be < 0.
> >
> > ...
> >
> > @@ -208,8 +208,6 @@ static int test_no_kmem_bypass(const char *root)
> > free(trigger_allocation);
> > if (get_zswap_stored_pages(&stored_pages))
> > break;
> > - if (stored_pages < 0)
> > - break;
> > /* If memory was pushed to zswap, verify it belongs to memcg */
> > if (stored_pages > stored_pages_threshold) {
> > int zswapped = cg_read_key_long(test_group, "memory.stat", "zswapped ");
>
> stored_pages will be set to -1 on error. It would be better to cast
> stored_pages to ssize_t in the check, rather than simply ignoring
> errors?
I'm not sure I understood, isn't it safe to just rely on the return value of
get_zswap_stored_pages a few lines above? In that case we break the loop and
the value of stored_pages is not used.