mm: generalize putback scan functions (a222f341) · Commits · 戴 / test

mm/vmscan.c

+40 −82

Original line number	Diff line number	Diff line
		@@ -1807,33 +1807,53 @@ static int too_many_isolated(struct pglist_data *pgdat, int file,
		return isolated > inactive;
		}

		static noinline_for_stack void
		putback_inactive_pages(struct lruvec lruvec, struct list_head page_list)
		/*
		* This moves pages from @list to corresponding LRU list.
		*
		* We move them the other way if the page is referenced by one or more
		* processes, from rmap.
		*
		* If the pages are mostly unmapped, the processing is fast and it is
		* appropriate to hold zone_lru_lock across the whole operation. But if
		* the pages are mapped, the processing is slow (page_referenced()) so we
		* should drop zone_lru_lock around each page. It's impossible to balance
		* this, so instead we remove the pages from the LRU while processing them.
		* It is safe to rely on PG_active against the non-LRU pages in here because
		* nobody will play with that bit on a non-LRU page.
		*
		* The downside is that we have to touch page->_refcount against each page.
		* But we had to alter page->flags anyway.
		*
		* Returns the number of pages moved to the given lruvec.
		*/

		static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
		struct list_head *list)
		{
		struct pglist_data *pgdat = lruvec_pgdat(lruvec);
		int nr_pages, nr_moved = 0;
		LIST_HEAD(pages_to_free);
		struct page *page;
		enum lru_list lru;

		/*
		* Put back any unfreeable pages.
		*/
		while (!list_empty(page_list)) {
		struct page *page = lru_to_page(page_list);
		int lru;

		while (!list_empty(list)) {
		page = lru_to_page(list);
		VM_BUG_ON_PAGE(PageLRU(page), page);
		list_del(&page->lru);
		if (unlikely(!page_evictable(page))) {
		list_del(&page->lru);
		spin_unlock_irq(&pgdat->lru_lock);
		putback_lru_page(page);
		spin_lock_irq(&pgdat->lru_lock);
		continue;
		}

		lruvec = mem_cgroup_page_lruvec(page, pgdat);

		SetPageLRU(page);
		lru = page_lru(page);
		add_page_to_lru_list(page, lruvec, lru);

		nr_pages = hpage_nr_pages(page);
		update_lru_size(lruvec, lru, page_zonenum(page), nr_pages);
		list_move(&page->lru, &lruvec->lists[lru]);

		if (put_page_testzero(page)) {
		__ClearPageLRU(page);
		@@ -1847,13 +1867,17 @@ putback_inactive_pages(struct lruvec lruvec, struct list_head page_list)
		spin_lock_irq(&pgdat->lru_lock);
		} else
		list_add(&page->lru, &pages_to_free);
		} else {
		nr_moved += nr_pages;
		}
		}

		/*
		* To save our caller's stack, now use input list for pages to free.
		*/
		list_splice(&pages_to_free, page_list);
		list_splice(&pages_to_free, list);

		return nr_moved;
		}

		/*
		@@ -1945,7 +1969,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
		reclaim_stat->recent_rotated[0] = stat.nr_activate[0];
		reclaim_stat->recent_rotated[1] = stat.nr_activate[1];

		putback_inactive_pages(lruvec, &page_list);
		move_pages_to_lru(lruvec, &page_list);

		__mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, -nr_taken);

		@@ -1982,72 +2006,6 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
		return nr_reclaimed;
		}

		/*
		* This moves pages from the active list to the inactive list.
		*
		* We move them the other way if the page is referenced by one or more
		* processes, from rmap.
		*
		* If the pages are mostly unmapped, the processing is fast and it is
		* appropriate to hold pgdat->lru_lock across the whole operation. But if
		* the pages are mapped, the processing is slow (page_referenced()) so we
		* should drop pgdat->lru_lock around each page. It's impossible to balance
		* this, so instead we remove the pages from the LRU while processing them.
		* It is safe to rely on PG_active against the non-LRU pages in here because
		* nobody will play with that bit on a non-LRU page.
		*
		* The downside is that we have to touch page->_refcount against each page.
		* But we had to alter page->flags anyway.
		*
		* Returns the number of pages moved to the given lru.
		*/

		static unsigned move_active_pages_to_lru(struct lruvec *lruvec,
		struct list_head *list,
		enum lru_list lru)
		{
		struct pglist_data *pgdat = lruvec_pgdat(lruvec);
		LIST_HEAD(pages_to_free);
		struct page *page;
		int nr_pages;
		int nr_moved = 0;

		while (!list_empty(list)) {
		page = lru_to_page(list);
		lruvec = mem_cgroup_page_lruvec(page, pgdat);

		VM_BUG_ON_PAGE(PageLRU(page), page);
		SetPageLRU(page);

		nr_pages = hpage_nr_pages(page);
		update_lru_size(lruvec, lru, page_zonenum(page), nr_pages);
		list_move(&page->lru, &lruvec->lists[lru]);

		if (put_page_testzero(page)) {
		__ClearPageLRU(page);
		__ClearPageActive(page);
		del_page_from_lru_list(page, lruvec, lru);

		if (unlikely(PageCompound(page))) {
		spin_unlock_irq(&pgdat->lru_lock);
		mem_cgroup_uncharge(page);
		(*get_compound_page_dtor(page))(page);
		spin_lock_irq(&pgdat->lru_lock);
		} else
		list_add(&page->lru, &pages_to_free);
		} else {
		nr_moved += nr_pages;
		}
		}

		/*
		* To save our caller's stack, now use input list for pages to free.
		*/
		list_splice(&pages_to_free, list);

		return nr_moved;
		}

		static void shrink_active_list(unsigned long nr_to_scan,
		struct lruvec *lruvec,
		struct scan_control *sc,
		@@ -2134,8 +2092,8 @@ static void shrink_active_list(unsigned long nr_to_scan,
		*/
		reclaim_stat->recent_rotated[file] += nr_rotated;

		nr_activate = move_active_pages_to_lru(lruvec, &l_active, lru);
		nr_deactivate = move_active_pages_to_lru(lruvec, &l_inactive, lru - LRU_ACTIVE);
		nr_activate = move_pages_to_lru(lruvec, &l_active);
		nr_deactivate = move_pages_to_lru(lruvec, &l_inactive);
		/* Keep all free pages in l_active list */
		list_splice(&l_inactive, &l_active);

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