From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932162Ab0EZQol (ORCPT ); Wed, 26 May 2010 12:44:41 -0400 Received: from cantor.suse.de ([195.135.220.2]:49855 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755885Ab0EZQok (ORCPT ); Wed, 26 May 2010 12:44:40 -0400 Date: Thu, 27 May 2010 02:44:37 +1000 From: Nick Piggin To: Dave Chinner Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, xfs@oss.sgi.com Subject: Re: [PATCH 0/5] Per superblock shrinkers V2 Message-ID: <20100526164437.GE22536@laptop> References: <1274777588-21494-1-git-send-email-david@fromorbit.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1274777588-21494-1-git-send-email-david@fromorbit.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 25, 2010 at 06:53:03PM +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. Seems like a fairly good approach overall. Thanks.