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

[Baolin Wang]

On 2/15/2023 1:52 AM, David Hildenbrand wrote:
> 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@xxxxxxxxxx>

Thanks.

> 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.

Yes, pretty clear. Will do in next version.