Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933849AbXK2TwD (ORCPT ); Thu, 29 Nov 2007 14:52:03 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933762AbXK2Tvl (ORCPT ); Thu, 29 Nov 2007 14:51:41 -0500 Received: from smtp-out.google.com ([216.239.45.13]:41005 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933721AbXK2Tvj (ORCPT ); Thu, 29 Nov 2007 14:51:39 -0500 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=received:message-id:date:from:to:subject:cc:in-reply-to: mime-version:content-type:content-transfer-encoding: content-disposition:references; b=N/UijVYFbfy5ipubrXwVpe8KnmHAnAhY3xjNf+R2hhRrjuRUswGb0Uut+x3FcN6PQ pE6DmUJ+ses5aemslme8A== Message-ID: <532480950711291151g25e24b8mf5dc453ac654a3e1@mail.gmail.com> Date: Thu, 29 Nov 2007 11:51:25 -0800 From: "Michael Rubin" To: "Fengguang Wu" Subject: Re: [patch 1/1] Writeback fix for concurrent large and small file writes Cc: a.p.zijlstra@chello.nl, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Chris Mason" In-Reply-To: <396296481.07368@ustc.edu.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20071128192957.511EAB8310@localhost> <396296481.07368@ustc.edu.cn> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3230 Lines: 76 So Feng's one line change fixes the problem at hand. I will do some more testing with it and then submit his patch credited with him for 2.6.24. If that's cool with Feng. Also I will take the comment changes and re-submit my patch for 2.6.25 for general purpose improvement and see what happens. mrubin On Nov 28, 2007 4:34 PM, Fengguang Wu wrote: > On Wed, Nov 28, 2007 at 11:29:57AM -0800, Michael Rubin wrote: > > >From mrubin@matchstick.corp.google.com Wed Nov 28 11:10:06 2007 > > Message-Id: <20071128190121.716364000@matchstick.corp.google.com> > > Date: Wed, 28 Nov 2007 11:01:21 -0800 > > From: mrubin@google.com > > To: mrubin@google.com > > Subject: [patch 1/1] Writeback fix for concurrent large and small file writes. > > > > From: Michael Rubin > > > > Fixing a bug where writing to large files while concurrently writing to > > smaller ones creates a situation where writeback cannot keep up with the > > Could you demonstrate the situation? Or if I guess it right, could it > be fixed by the following patch? (not a nack: If so, your patch could > also be considered as a general purpose improvement, instead of a bug > fix.) > > diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c > index 0fca820..62e62e2 100644 > --- a/fs/fs-writeback.c > +++ b/fs/fs-writeback.c > @@ -301,7 +301,7 @@ __sync_single_inode(struct inode *inode, struct writeback_control *wbc) > * Someone redirtied the inode while were writing back > * the pages. > */ > - redirty_tail(inode); > + requeue_io(inode); > } else if (atomic_read(&inode->i_count)) { > /* > * The inode is clean, inuse > > Thank you, > Fengguang > > > > traffic and memory baloons until the we hit the threshold watermark. This > > can result in surprising latency spikes when syncing. This latency > > can take minutes on large memory systems. Upon request I can provide > > a test to reproduce this situation. The flush tree fixes this issue and > > fixes several other minor issues with fairness also. > > > > 1) Adding a data structure to guarantee fairness when writing inodes > > to disk. The flush_tree is based on an rbtree. The only difference is > > how duplicate keys are chained off the same rb_node. > > > > 2) Added a FS flag to mark file systems that are not disk backed so we > > don't have to flush them. Not sure I marked all of them. But just marking > > these improves writeback performance. > > > > 3) Added an inode flag to allow inodes to be marked so that they are > > never written back to disk. See get_pipe_inode. > > > > Under autotest this patch has passed: fsx, bonnie, and iozone. I am > > currently writing more writeback focused tests (which so far have been > > passed) to add into autotest. > > > > Signed-off-by: Michael Rubin > > --- > > - 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/