Messages in this thread Patch in this message | | | Date | Wed, 22 Apr 2020 09:07:51 -0400 | From | Johannes Weiner <> | Subject | Re: [PATCH v2] mm/vmscan: count layzfree pages and fix nr_isolated_* mismatch |
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On Wed, Apr 22, 2020 at 05:48:15PM +0900, Jaewon Kim wrote: > @@ -1295,11 +1295,15 @@ static unsigned long shrink_page_list(struct list_head *page_list, > */ > if (page_mapped(page)) { > enum ttu_flags flags = ttu_flags | TTU_BATCH_FLUSH; > + bool lazyfree = PageAnon(page) && !PageSwapBacked(page); > > if (unlikely(PageTransHuge(page))) > flags |= TTU_SPLIT_HUGE_PMD; > + > if (!try_to_unmap(page, flags)) { > stat->nr_unmap_fail += nr_pages; > + if (lazyfree && PageSwapBacked(page))
This looks pretty strange, until you remember that try_to_unmap() could SetPageSwapbacked again.
This might be more obvious?
was_swapbacked = PageSwapBacked(page); if (!try_to_unmap(page, flags)) { stat->nr_unmap_fail += nr_pages; if (!was_swapbacked && PageSwapBacked(page)) > + stat->nr_lazyfree_fail += nr_pages; > goto activate_locked;
Or at least was_lazyfree.
> @@ -1491,8 +1495,8 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone, > .priority = DEF_PRIORITY, > .may_unmap = 1, > }; > - struct reclaim_stat dummy_stat; > - unsigned long ret; > + struct reclaim_stat stat; > + unsigned long reclaimed;
nr_reclaimed would be better.
I also prefer keeping dummy_stat, since that's still what it is.
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