From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wu Fengguang Subject: Re: [PATCH 03/13] writeback: per-task rate limit on balance_dirty_pages() Date: Wed, 17 Nov 2010 22:39:03 +0800 Message-ID: <20101117143903.GA11664@localhost> References: <20101117042720.033773013@intel.com> <20101117042849.650810571@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jan Kara , Christoph Hellwig , Dave Chinner , Theodore Ts'o , Chris Mason , Peter Zijlstra , Mel Gorman , Rik van Riel , KOSAKI Motohiro , linux-mm , "linux-fsdevel@vger.kernel.org" , LKML To: Andrew Morton Return-path: Received: from mga03.intel.com ([143.182.124.21]:38045 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933812Ab0KQOjK (ORCPT ); Wed, 17 Nov 2010 09:39:10 -0500 Content-Disposition: inline In-Reply-To: <20101117042849.650810571@intel.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: > + if (pause == 0 && nr_dirty < background_thresh) > + current->nr_dirtied_pause = ratelimit_pages(bdi); > + else if (pause == 1) > + current->nr_dirtied_pause += current->nr_dirtied_pause >> 5; Sorry here is a bug fix for the above line, it's also pushed to the git tree. Thanks, Fengguang --- Subject: writeback: fix increasement of nr_dirtied_pause Date: Wed Nov 17 22:31:26 CST 2010 Fix a bug that current->nr_dirtied_pause += current->nr_dirtied_pause >> 5; does not effectively increase nr_dirtied_pause when it's <= 32. Thus nr_dirtied_pause may never grow up.. Signed-off-by: Wu Fengguang --- mm/page-writeback.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- linux-next.orig/mm/page-writeback.c 2010-11-17 22:31:09.000000000 +0800 +++ linux-next/mm/page-writeback.c 2010-11-17 22:31:23.000000000 +0800 @@ -662,7 +662,7 @@ pause: if (pause == 0 && nr_dirty < background_thresh) current->nr_dirtied_pause = ratelimit_pages(bdi); else if (pause == 1) - current->nr_dirtied_pause += current->nr_dirtied_pause >> 5; + current->nr_dirtied_pause += current->nr_dirtied_pause / 32 + 1; else if (pause >= HZ/10) /* * when repeated, writing 1 page per 100ms on slow devices,