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

Ilpo Järvinen
2023-12-14T10:16:50Z

[-- Attachment #1: Type: text/plain, Size: 947 bytes --]

On Wed, 13 Dec 2023, Reinette Chatre wrote:

> 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?

Okay. I also now noticed the return type is not what it should be.

--
i.