Re: [PATCH v3 03/13] xen: introduce cpumask_from_bitmap

[Keir Fraser <keir.xen@gmail.com>]

On 25/04/2013 13:49, "Jan Beulich" <JBeulich@suse.com> wrote:

>>>>>>> And most importantly: Why? This isn't an operation that should
>>>>>>> commonly be done, and hence having a utility function for this
>>>>>>> seems to invite for abuse rather than really help.
>>>>>> 
>>>>>> TBH I have done it to address Ian's comment, I don't have a strong
>>>>>> opinion on this.
>>>>>> However it is true that from an API point of view, cpumask_from_bitmap
>>>>>> allows us to cover the new use case without breaking the cpumask
>>>>>> abstraction.
>>>>> 
>>>>> Rather than adding a new abstraction that's used for a single
>>>>> special case, and if open coding is undesirable, I'd prefer if you
>>>>> used bitmap_to_xenctl_bitmap() plus xenctl_bitmap_to_cpumask()
>>>>> if at all possible.
>>>> 
>>>> Both functions do copy_to/from_guest and use xmalloc, I don't think I
>>>> can use them.
>>> 
>>> Hmm, ugly. But okay then...
>> 
>> Is that an ack? ;-)
> 
> No, this is at best an "I won't object to this anymore, but I still
> don't like it".

If I am convinced that the usage case is sane, I'll ack a one-use helper. I
have no problem with one-use helpers! To me this would be a perfectly
reasonable cpumask_t constructor fn.

 -- Keir

> Jan
>