Re: [RFC 06/11] mm: remove SWAP_MLOCK in ttu

[Anshuman Khandual]

On 03/02/2017 12:09 PM, Minchan Kim wrote:
> ttu don't need to return SWAP_MLOCK. Instead, just return SWAP_FAIL
> because it means the page is not-swappable so it should move to
> another LRU list(active or unevictable). putback friends will
> move it to right list depending on the page's LRU flag.

Right, if it cannot be swapped out there is not much difference with
SWAP_FAIL once we change the callers who expected to see a SWAP_MLOCK
return instead.

> 
> A side effect is shrink_page_list accounts unevictable list movement
> by PGACTIVATE but I don't think it corrupts something severe.

Not sure I got that, could you please elaborate on this. We will still
activate the page and put it in an appropriate LRU list if it is marked
mlocked ?