From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id o4RKUHt3162282 for ; Thu, 27 May 2010 15:30:18 -0500 Received: from smtp1.linux-foundation.org (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 3DB35149D817 for ; Thu, 27 May 2010 13:34:33 -0700 (PDT) Received: from smtp1.linux-foundation.org (smtp1.linux-foundation.org [140.211.169.13]) by cuda.sgi.com with ESMTP id 5QZZSY7os4yNQlih for ; Thu, 27 May 2010 13:34:33 -0700 (PDT) Date: Thu, 27 May 2010 13:32:23 -0700 From: Andrew Morton Subject: Re: [PATCH 0/5] Per superblock shrinkers V2 Message-Id: <20100527133223.efa4740a.akpm@linux-foundation.org> In-Reply-To: <1274777588-21494-1-git-send-email-david@fromorbit.com> References: <1274777588-21494-1-git-send-email-david@fromorbit.com> Mime-Version: 1.0 List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Dave Chinner Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, xfs@oss.sgi.com On Tue, 25 May 2010 18:53:03 +1000 Dave Chinner wrote: > This series reworks the filesystem shrinkers. We currently have a > set of issues with the current filesystem shrinkers: > > 1. There is an dependency between dentry and inode cache > shrinking that is only implicitly defined by the order of > shrinker registration. > 2. The shrinkers need to walk the superblock list and pin > the superblock to avoid unmount races with the sb going > away. > 3. The dentry cache uses per-superblock LRUs and proportions > reclaim between all the superblocks which means we are > doing breadth based reclaim. This means we touch every > superblock for every shrinker call, and may only reclaim > a single dentry at a time from a given superblock. > 4. The inode cache has a global LRU, so it has different > reclaim patterns to the dentry cache, despite the fact > that the dentry cache is generally the only thing that > pins inodes in memory. > 5. Filesystems need to register their own shrinkers for > caches and can't co-ordinate them with the dentry and > inode cache shrinkers. Nice description, but... it never actually told us what the benefit of the changes are. Presumably some undescribed workload had some undescribed user-visible problem. But what was that workload, and what was the user-visible problem, and how does the patch affect all this? Stuff like that. _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs