Re: [PATCH] selftests: cgroup: fix test_zswap error path and meaningless check

[Andrew Morton]

On Tue, 12 Sep 2023 10:38:00 +0200 Domenico Cerasuolo <cerasuolodomenico@xxxxxxxxx> 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?