On Mon, Apr 17, 2023 at 03:56:43PM +0800, Yin Fengwei wrote:
> Currently, large folio is not batched added to lru list. Which
> cause high lru lock contention after enable large folio for
> anonymous mappping.
Obviously, I think we should be doing a batched add, but I don't think
this is right.
> @@ -54,7 +57,12 @@ static inline unsigned pagevec_space(struct pagevec *pvec)
> static inline unsigned pagevec_add(struct pagevec *pvec, struct page *page)
> {
> pvec->pages[pvec->nr++] = page;
> - return pagevec_space(pvec);
> + pvec->pages_nr += compound_nr(page);
> +
> + if (pvec->pages_nr > PAGEVEC_SIZE)
> + return 0;
> + else
> + return pagevec_space(pvec);
I assume your thinking here is that we should limit the number of pages
in the batches, but I think we should allow the number of folios to reach
PAGEVEC_SIZE before we drain the batch onto the LRU list. That will
reduce the contention on the LRU lock even further.
