Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756751Ab0HEPM4 (ORCPT ); Thu, 5 Aug 2010 11:12:56 -0400 Received: from gir.skynet.ie ([193.1.99.77]:50642 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758937Ab0HEPMx (ORCPT ); Thu, 5 Aug 2010 11:12:53 -0400 Date: Thu, 5 Aug 2010 16:12:37 +0100 From: Mel Gorman To: KOSAKI Motohiro Cc: LKML , linux-mm , Andrew Morton , Johannes Weiner , Wu Fengguang , Minchan Kim , Rik van Riel Subject: Re: [PATCH 3/7] vmscan: synchrounous lumpy reclaim use lock_page() instead trylock_page() Message-ID: <20100805151237.GG25688@csn.ul.ie> References: <20100805150624.31B7.A69D9226@jp.fujitsu.com> <20100805151304.31C0.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20100805151304.31C0.A69D9226@jp.fujitsu.com> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1803 Lines: 61 On Thu, Aug 05, 2010 at 03:13:39PM +0900, KOSAKI Motohiro wrote: > When synchrounous lumpy reclaim, there is no reason to give up to > reclaim pages even if page is locked. We use lock_page() instead > trylock_page() in this case. > > Signed-off-by: KOSAKI Motohiro The intention of the code looks fine so; Acked-by: Mel Gorman Something like the following might just be easier on the eye but it's a question of personal taste. /* Returns true if the page is locked */ static bool lru_lock_page(struct page *page, enum pageout_io sync_writeback) { if (likely(sync_writeback == PAGEOUT_IO_ASYNC)) return trylock_page(page); lock_page(page); return true; } then replace trylock_page() with lru_lock_page(). The naming is vaguely similar to other helpers like lru_to_page > --- > mm/vmscan.c | 4 +++- > 1 files changed, 3 insertions(+), 1 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 1cdc3db..833b6ad 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -665,7 +665,9 @@ static unsigned long shrink_page_list(struct list_head *page_list, > page = lru_to_page(page_list); > list_del(&page->lru); > > - if (!trylock_page(page)) > + if (sync_writeback == PAGEOUT_IO_SYNC) > + lock_page(page); > + else if (!trylock_page(page)) > goto keep; > > VM_BUG_ON(PageActive(page)); > -- > 1.6.5.2 > > > -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/