From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jared Hulbert" Subject: Re: [PATCH 04/10] AXFS: axfs_inode.c Date: Fri, 22 Aug 2008 11:04:08 -0700 Message-ID: <6934efce0808221104w1609bea8mbbff54019c261d80@mail.gmail.com> References: <48AD00F0.5030403@gmail.com> <200808211417.14425.arnd@arndb.de> <48AE22F5.3000309@lougher.demon.co.uk> <200808221200.26052.arnd@arndb.de> <48AEF2A3.7020905@lougher.demon.co.uk> <20080822171959.GA30977@logfs.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:cc:in-reply-to:mime-version:content-type :content-transfer-encoding:content-disposition:references; bh=YlSc/Q6C/JKO05b5TZ5qL02yQiRe8TgaYht5IEYKg14=; b=WKFCVJN0634sepbnavA12bTZ7DIq/HkFaV6Ta3+P05bUCGuG898T8ibjzezzmNeYbW 3kV1KQhw/NvB2zL1Zim/DQJQfnqz5CtjEicmoUeY/Q10dNPYWYwn+OLyjjs4FyXo1kSF kzAypO3kMv5K+KceCMXwx6TmPQDphJMOwTPrc= In-Reply-To: <20080822171959.GA30977@logfs.org> Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: =?UTF-8?Q?J=C3=B6rn_Engel?= Cc: Phillip Lougher , Arnd Bergmann , Linux-kernel@vger.kernel.org, linux-embedded@vger.kernel.org, linux-mtd , tim.bird@am.sony.com, cotte@de.ibm.com, nickpiggin@yahoo.com.au > Elsewhere in this maze of threads Arnd claimed to have tested the > benefits of metadata compression - and it making little impact. > > My guess is that it would make a large impact if metadata would be a > significant part of the filesystem image. Usually metadata is close > enough to 0% to be mistaken for statistical noise. So compressing it > makes a significant impact on an insignificant amount of data. Like I said early it depends on the value you assign to significant. For a fs sizes I started designing to 16MB-64MB if you have to track a whole bunch of 8Byte numbers for every symlink, dev node, inode, and page. It adds up quickly to a couple of MB, that can translate to lots of money. Even at only an extra $0.25 a system * 12Million units = $3Million.