Messages in this thread Patch in this message | | | Date | Mon, 29 Nov 2010 15:29:51 +0800 | From | Wu Fengguang <> | Subject | Re: [PATCH v2 2/3] move ClearPageReclaim |
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On Sun, Nov 28, 2010 at 11:02:56PM +0800, Minchan Kim wrote: > 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. > This patch needs Wu's opinion.
It's a safe change. The possibility and consequence of races are both small enough. However the patch could be simplified as follows?
Thanks, Fengguang ---
--- linux-next.orig/mm/page-writeback.c 2010-11-29 15:14:54.000000000 +0800 +++ linux-next/mm/page-writeback.c 2010-11-29 15:15:02.000000000 +0800 @@ -1330,6 +1330,7 @@ int set_page_dirty(struct page *page) { struct address_space *mapping = page_mapping(page); + ClearPageReclaim(page); if (likely(mapping)) { int (*spd)(struct page *) = mapping->a_ops->set_page_dirty; #ifdef CONFIG_BLOCK @@ -1387,7 +1388,6 @@ int clear_page_dirty_for_io(struct page BUG_ON(!PageLocked(page)); - ClearPageReclaim(page); if (mapping && mapping_cap_account_dirty(mapping)) { /* * Yes, Virginia, this is indeed insane.
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