Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759168Ab0GVAC0 (ORCPT ); Wed, 21 Jul 2010 20:02:26 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:36984 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759124Ab0GVACZ (ORCPT ); Wed, 21 Jul 2010 20:02:25 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Date: Thu, 22 Jul 2010 08:57:34 +0900 From: KAMEZAWA Hiroyuki To: Mel Gorman Cc: Johannes Weiner , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Dave Chinner , Chris Mason , Nick Piggin , Rik van Riel , Christoph Hellwig , Wu Fengguang , KOSAKI Motohiro , Andrew Morton , Andrea Arcangeli Subject: Re: [PATCH 4/8] vmscan: Do not writeback filesystem pages in direct reclaim Message-Id: <20100722085734.ff252542.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20100721142710.GZ13117@csn.ul.ie> References: <1279545090-19169-1-git-send-email-mel@csn.ul.ie> <1279545090-19169-5-git-send-email-mel@csn.ul.ie> <20100719221420.GA16031@cmpxchg.org> <20100720134555.GU13117@csn.ul.ie> <20100720220218.GE16031@cmpxchg.org> <20100721115250.GX13117@csn.ul.ie> <20100721210111.06dda351.kamezawa.hiroyu@jp.fujitsu.com> <20100721142710.GZ13117@csn.ul.ie> Organization: FUJITSU Co. LTD. X-Mailer: Sylpheed 3.0.3 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2274 Lines: 73 On Wed, 21 Jul 2010 15:27:10 +0100 Mel Gorman wrote: > On Wed, Jul 21, 2010 at 09:01:11PM +0900, KAMEZAWA Hiroyuki wrote: > > But, hmm, memcg will have to select to enter this rounine based on > > the result of 1st memory reclaim. > > > > It has the option of igoring pages being dirtied but I worry that the > container could be filled with dirty pages waiting for flushers to do > something. I'll prepare dirty_ratio for memcg. It's not easy but requested by I/O cgroup guys, too... > > > > > > > - /* > > > - * The attempt at page out may have made some > > > - * of the pages active, mark them inactive again. > > > - */ > > > - nr_active = clear_active_flags(&page_list, NULL); > > > - count_vm_events(PGDEACTIVATE, nr_active); > > > + while (nr_reclaimed < nr_taken && nr_dirty && dirty_retry--) { > > > + wakeup_flusher_threads(laptop_mode ? 0 : nr_dirty); > > > + congestion_wait(BLK_RW_ASYNC, HZ/10); > > > > > > > Congestion wait is required ?? Where the congestion happens ? > > I'm sorry you already have some other trick in other patch. > > > > It's to wait for the IO to occur. > 1 tick penalty seems too large. I hope we can have some waitqueue in future. > > > - nr_reclaimed += shrink_page_list(&page_list, sc, PAGEOUT_IO_SYNC); > > > + /* > > > + * The attempt at page out may have made some > > > + * of the pages active, mark them inactive again. > > > + */ > > > + nr_active = clear_active_flags(&page_list, NULL); > > > + count_vm_events(PGDEACTIVATE, nr_active); > > > + > > > + nr_reclaimed += shrink_page_list(&page_list, sc, > > > + PAGEOUT_IO_SYNC, &nr_dirty); > > > + } > > > > Just a question. This PAGEOUT_IO_SYNC has some meanings ? > > > > Yes, in pageout it will wait on pages currently being written back to be > cleaned before trying to reclaim them. > Hmm. IIUC, this routine is called only when !current_is_kswapd() and pageout is done only whne current_is_kswapd(). So, this seems .... Wrong ? Thanks, -Kame -- 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/