Re: [PATCH 0/3] Some cleanups for page isolation

[Baolin Wang <baolin.wang-KPsoFbNs7GizrGE5bRqYAgC/G2K4zDHf@public.gmane.org>]

On 2/14/2023 12:50 PM, Matthew Wilcox wrote:
> On Tue, Feb 14, 2023 at 11:18:05AM +0800, Baolin Wang wrote:
>> 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 it's better to check the negative error explicitly
>> for isolation to make the code more clear per Linus's suggestion in [1].
> 
> Only one caller of isolate_lru_page() or folio_isolate_lru() actually
> uses the errno.  And the errno can only be 0 or -EBUSY.  It'd be
> better to change the three functions to return bool and fix
> add_page_for_migration() to set the errno to -EBUSY itself.

Sounds reasonable to me, and I can change them to return bool in next 
version. Thanks.