From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 9CAA36B02AC for ; Thu, 5 Aug 2010 09:54:31 -0400 (EDT) Received: by pwj7 with SMTP id 7so67914pwj.14 for ; Thu, 05 Aug 2010 06:55:13 -0700 (PDT) Date: Thu, 5 Aug 2010 22:55:04 +0900 From: Minchan Kim Subject: Re: [PATCH 2/7] vmscan: synchronous lumpy reclaim don't call congestion_wait() Message-ID: <20100805135504.GA2985@barrios-desktop> References: <20100805150624.31B7.A69D9226@jp.fujitsu.com> <20100805151229.31BD.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100805151229.31BD.A69D9226@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: LKML , linux-mm , Andrew Morton , Johannes Weiner , Mel Gorman , Wu Fengguang , Rik van Riel List-ID: On Thu, Aug 05, 2010 at 03:13:03PM +0900, KOSAKI Motohiro wrote: > congestion_wait() mean "waiting quueue congestion is cleared". > That said, if the system have plenty dirty pages and flusher thread push > new request to IO queue conteniously, IO queue are not cleared > congestion status for long time. thus, congestion_wait(HZ/10) become > almostly equivalent schedule_timeout(HZ/10). > > However, synchronous lumpy reclaim donesn't need this > congestion_wait() at all. shrink_page_list(PAGEOUT_IO_SYNC) are > using wait_on_page_writeback() and it provide sufficient waiting. > > Signed-off-by: KOSAKI Motohiro Reviewed-by: Minchan Kim -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org