On Thu, Feb 08, 2018 at 10:36:35AM +0900, Sergey Senozhatsky wrote:
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);}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?
I didn't want to spread out frontswap stuff unless it has good value because most of frontswap functions are located in mm/swapfile.c at this moment. It gives me good feeling frontswap's abstraction is wonderful. However, if frontswap matainer has no problem, I am not against, either.
Thanks.