From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nick Piggin Subject: Re: [patch 37/52] fs: icache lazy lru Date: Wed, 30 Jun 2010 22:06:31 +1000 Message-ID: <20100630120631.GC21358@laptop> References: <20100624030212.676457061@suse.de> <20100624030731.563540438@suse.de> <20100630083814.GG24712@dastard> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, John Stultz , Frank Mayhar To: Dave Chinner Return-path: Content-Disposition: inline In-Reply-To: <20100630083814.GG24712@dastard> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Wed, Jun 30, 2010 at 06:38:14PM +1000, Dave Chinner wrote: > On Thu, Jun 24, 2010 at 01:02:49PM +1000, npiggin@suse.de wrote: > > Impelemnt lazy inode lru similarly to dcache. This will reduce lock > > acquisition and will help to improve lock ordering subsequently. > > I'm not sure we want the I_REFERENCED reclaim free pass for a clean > inode that has been put on the LRU directly. I can see exactly how > it is benficial to delay reclaim of dirty inodes (XFS uses that > trick), but in terms of aging the cache we've already done this > free pass trick at the dentry level. Hence I think the frequent > separate access patterns tend to be filtered out at the dcache level > and hence we don't need to handle that in the inode cache. > > Perhaps we only need the I_REFERENCED flag to give dirty inodes a > chance to be flushed by other means before forcing reclaim to do > inode writeback? It doesn't force flush, but it force invalidates pagecache.