From: Ted Ts'o Subject: Re: fsck performance. Date: Tue, 22 Feb 2011 17:13:04 -0500 Message-ID: <20110222221304.GH2924@thunk.org> References: <20110220222013.GA2849@thunk.org> <20110220231514.GC21917@bitwizard.nl> <20110220234131.GC4001@thunk.org> <20110222102056.GH21917@bitwizard.nl> <20110222133652.GI21917@bitwizard.nl> <20110222135431.GK21917@bitwizard.nl> <386B23FA-CE6E-4D9C-9799-C121B2E8C3BB@dilger.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Rogier Wolff , Pawe?? Brodacki , Amir Goldstein , "linux-ext4@vger.kernel.org" To: Andreas Dilger Return-path: Received: from li9-11.members.linode.com ([67.18.176.11]:36579 "EHLO test.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751361Ab1BVWNK (ORCPT ); Tue, 22 Feb 2011 17:13:10 -0500 Content-Disposition: inline In-Reply-To: <386B23FA-CE6E-4D9C-9799-C121B2E8C3BB@dilger.ca> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Tue, Feb 22, 2011 at 09:32:28AM -0700, Andreas Dilger wrote: > > Any idea what the hash size does to memory usage? I wonder if we > can scale this based on the directory count, or if the memory usage > is minimal (only needed in case of tdb) then just make it the > default. It definitely appears to have been a major performance > boost. Yeah, that was my question. Your patch adds a magic number which probably works well on your machine (and I'm not really worried if someone has less than 1G --- here's a quarter kid, buy your self a real computer :-). But I wonder if we should be using a hash size which is sized automatically depending on available memory or file system size. - Ted