On (02/07/18 13:05), Andrew Morton wrote: [..] > hm. This is assuming that "cluster==true" means "this is thp swap". > That's presently true, but is it appropriate that get_swap_pages() is > peeking at "cluster" to work out why it is being called? > > Or would it be cleaner to do this in get_swap_page()? Something like > > --- a/mm/swap_slots.c~a > +++ a/mm/swap_slots.c > @@ -317,8 +317,11 @@ swp_entry_t get_swap_page(struct page *p > entry.val = 0; > > if (PageTransHuge(page)) { > - if (IS_ENABLED(CONFIG_THP_SWAP)) > - get_swap_pages(1, true, &entry); > + /* Frontswap doesn't support THP */ > + if (!frontswap_enabled()) { > + if (IS_ENABLED(CONFIG_THP_SWAP)) > + get_swap_pages(1, true, &entry); > + } > return entry; > } I have proposed exactly the same thing [1], Minchan commented that it would introduce frontswap dependency to swap_slots.c [2]. Which is true, but I'd still probably prefer to handle it all in get_swap_page. Minchan, any objections? [1] https://marc.info/?l=linux-mm&m=151791052007719&w=2 [2] https://marc.info/?l=linux-mm&m=151792646812617&w=2 -ss