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SubjectRe: [PATCH 2/3] Reclaim invalidated page ASAP
> invalidate_mapping_pages is very big hint to reclaimer.
> It means user doesn't want to use the page any more.
> So in order to prevent working set page eviction, this patch
> move the page into tail of inactive list by PG_reclaim.
> Please, remember that pages in inactive list are working set
> as well as active list. If we don't move pages into inactive list's
> tail, pages near by tail of inactive list can be evicted although
> we have a big clue about useless pages. It's totally bad.
> Now PG_readahead/PG_reclaim is shared.
> fe3cba17 added ClearPageReclaim into clear_page_dirty_for_io for
> preventing fast reclaiming readahead marker page.
> In this series, PG_reclaim is used by invalidated page, too.
> If VM find the page is invalidated and it's dirty, it sets PG_reclaim
> to reclaim asap. Then, when the dirty page will be writeback,
> clear_page_dirty_for_io will clear PG_reclaim unconditionally.
> It disturbs this serie's goal.
> I think it's okay to clear PG_readahead when the page is dirty, not
> writeback time. So this patch moves ClearPageReadahead.
> Signed-off-by: Minchan Kim <>
> Acked-by: Rik van Riel <>
> Cc: Wu Fengguang <>
> Cc: KOSAKI Motohiro <>
> Cc: Johannes Weiner <>
> Cc: Nick Piggin <>
> Cc: Mel Gorman <>

I still dislike this one. I doubt this trick makes much benefit in real
world workload.

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