Re: [PATCH v3 09/29] selftests/resctrl: Create cache_portion_size() helper

Reinette Chatre
2023-12-13T21:56:06Z

Hi Ilpo,

On 12/11/2023 4:18 AM, Ilpo Järvinen wrote:
> +/*
> + * cache_portion_size - Calculate the size of a cache portion
> + * @cache_size: Total cache size in bytes
> + * @portion_mask: Cache portion mask
> + * @full_cache_mask: Full Cache Bit Mask (CBM) for the cache
> + *
> + * Return: The size of the cache portion in bytes.
> + */
> +static inline int cache_portion_size(unsigned long cache_size,
> + unsigned long portion_mask,
> + unsigned long full_cache_mask)
> +{
> + return cache_size * count_bits(portion_mask) / count_bits(full_cache_mask);
> +}
> +

Even after you added the new zero check the static checker I tried
was not able to recognize that this is safe. Could you please add a check
to ensure that there will be no divide-by-zero here?

Reinette