On 2024/5/10 0:58, Mat Martineau wrote:
...
>>
>> +/**
>> + * page_frag_alloc_probe - Probe the avaiable page fragment.
>> + * @nc: page_frag cache from which to probe
>> + * @offset: out as the offset of the page fragment
>> + * @fragsz: in as the requested size, out as the available size
>
> Hi Yunsheng -
>
> fragsz is never used as an input in this function. I think it would be good to make the code consistent with this documentation by checking that *fragsz <= (nc)->remaining
Yes, you are right.
It is not used as input, will update the documentation according.
>
>> + * @va: out as the virtual address of the returned page fragment
>> + *
>> + * Probe the current available memory to caller without doing cache refilling.
>> + * If the cache is empty, return NULL.
>
> Instead of this line, is it more accurate to say "if no space is available in the page_frag cache, return NULL" ?
>
> I also suggest adding some documentation here like:
>
> "If the requested space is available, up to fragsz bytes may be added to the fragment using page_frag_alloc_commit()".
Ok.
>
>> + *
>> + * Return:
>> + * Return the page fragment, otherwise return NULL.
>> + */
>> #define page_frag_alloc_probe(nc, offset, fragsz, va) \
>> ({ \
>> struct encoded_va *__encoded_va; \
>> @@ -162,6 +241,13 @@ static inline struct encoded_va *__page_frag_alloc_probe(struct page_frag_cache
>> __page; \
>> })
>>
>> +/**
>> + * page_frag_alloc_commit - Commit allocing a page fragment.
>> + * @nc: page_frag cache from which to commit
>> + * @fragsz: size of the page fragment has been used
>> + *
>> + * Commit the alloc preparing by passing the actual used size.
>
> Rephrasing suggestion:
>
> "Commit the actual used size for the allocation that was either prepared or probed"
Ok.
Thanks.
>
>
> Thanks,
>
> Mat
>
