Re: [PATCH v10] mm: vmscan: try to reclaim swapcache pages if no swap space

Huang, Ying
2023-11-27T02:36:55Z

Michal Hocko <mhocko@suse.com> writes:

> On Thu 23-11-23 14:15:59, Huang, Ying wrote:
>> Michal Hocko <mhocko@suse.com> writes:
> [...]
>> > Yes swapcache pages are indeed more complicated but most of the time
>> > they just go away as well, no?
>>
>> When we swapin a page, we will put it in swapcache too. And the page
>> can be in that state for long time if there is more than 50% free space
>> in the swap device.
>
> True, but why is that a problem? If you encounter such a swapped in page
> on the file LRU then the page should be referened and as such should be
> activated, no?

This just means that anonymous pages in file LRU aren't temporary or
short-term. So we need to consider that. For example, the original
method to balance between anonymous pages and file pages need to be
re-designed. The anonymous pages are considered hotter than file pages
in general.

--
Best Regards,
Huang, Ying