Re: [PATCH v2 0/4] Change the return value for page isolation functions

[David Hildenbrand <david@redhat.com>]

On 14.02.23 14:59, Baolin Wang wrote:
> Now the page isolation functions did not return a boolean to indicate
> success or not, instead it will return a negative error when failed
> to isolate a page. So below code used in most places seem a boolean
> success/failure thing, which can confuse people whether the isolation
> is successful.
> 
> if (folio_isolate_lru(folio))
>          continue;
> 
> Moreover the page isolation functions only return 0 or -EBUSY, and
> most users did not care about the negative error except for few users,
> thus we can convert all page isolation functions to return a boolean
> value, which can remove the confusion to make code more clear.
> 
> No functional changes intended in this patch series.
> 
> Changes from v1:
>   - Convert all isolation functions to return bool.

Acked-by: David Hildenbrand <david@redhat.com>

Although it's controversial if

if (!ret)
	ret = -EBUSY;
else
	ret = 0;

is really appealing to the readers eye :)

ret = ret ? 0 : -EBUSY;

It's still confusing.

would be better as

ret = isolated ? 0 : -EBUSY;

IOW, not reusing the "int ret" variable.

-- 
Thanks,

David / dhildenb