Re: [PATCH bpf-next v4 2/2] bpf: htab: Reduce elem_size by 8 bytes for small key sizes

> diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
> index fed4b1db8b78b..720766121ea2b 100644
> --- a/kernel/bpf/hashtab.c
> +++ b/kernel/bpf/hashtab.c

[ ... ]

> diff --git a/tools/testing/selftests/bpf/progs/map_ptr_kern.c b/tools/testing/selftests/bpf/progs/map_ptr_kern.c
> index 373c8d17ea557..6bd4cb68c20c1 100644
> --- a/tools/testing/selftests/bpf/progs/map_ptr_kern.c
> +++ b/tools/testing/selftests/bpf/progs/map_ptr_kern.c
> @@ -114,7 +114,7 @@ static inline int check_hash(void)
>  	VERIFY(check_default_noinline(&hash->map, map));
>
>  	VERIFY(hash->n_buckets == MAX_ENTRIES);
> -	VERIFY(hash->elem_size == 64);
> +	VERIFY(hash->elem_size == 32);
>
>  	VERIFY(hash->count.counter == 0);
>  	VERIFY(bpf_map_sum_elem_count(map) == 0);

Should this expectation change have been split across two commits for
bisectability? The preceding commit 1066507e33e67 dropped the
freelist/lru union from struct htab_elem, which moves elem_size to 40,
but that commit leaves the selftest checking for 64. This means the
map_ptr selftest fails at 1066507e33e67 and only passes again here
where elem_size becomes 32.


---
AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md

CI run summary: https://github.com/kernel-patches/bpf/actions/runs/31651309438