Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 18 Apr 2001 23:04:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 18 Apr 2001 23:04:40 -0400 Received: from garrincha.netbank.com.br ([200.203.199.88]:10256 "HELO netbank.com.br") by vger.kernel.org with SMTP id ; Wed, 18 Apr 2001 23:04:26 -0400 Date: Thu, 19 Apr 2001 00:02:40 -0300 (BRST) From: Rik van Riel To: Daniel Phillips Cc: jaharkes@cs.cmu.edu, adilger@turbolinux.com, ext2-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: Ext2 Directory Index - Delete Performance In-Reply-To: <20010419012241Z92303-1659+7@humbolt.nl.linux.org> Message-ID: X-spambait: aardvark@kernelnewbies.org X-spammeplease: aardvark@nl.linux.org MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 19 Apr 2001, Daniel Phillips wrote: > Jan Harkes wrote: > > On Thu, Apr 19, 2001 at 02:27:48AM +0200, Daniel Phillips wrote: > > > more memory. If you have enough memory, the inode cache won't thrash, > > > and even when it does, it does so gracefully - performance falls off > > > nice and slowly. For example, 250 Meg of inode cache will handle 2 > > > million inodes with no thrashing at all. > > > > What inode cache are you talking about? According to the slabinfo output > > on my machine every inode takes up 480 bytes in the inode_cache slab. So > > 250MB is only able to hold about half a million inodes in memory. > > Sorry, I was a little loose with terminology there. I should have > said "inode blocks in cache". The inode cache is related. When an > Ext2 inode is pushed out of the inode cache it gets transfered to a > dirty block in memory, where it shrinks to 128 bytes and shares the > block with 31 other inodes. These blocks are in the buffer cache, and > this is the cache I'm talking about. Hmmm, considering this, it may be wise to limit the amount of inodes in the inode cache to, say, 10% of RAM ... because we can cache MORE inodes if we store them in the buffer cache instead! regards, Rik -- Virtual memory is like a game you can't win; However, without VM there's truly nothing to lose... http://www.surriel.com/ http://www.conectiva.com/ http://distro.conectiva.com.br/ - 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/