From: Eric Sandeen Subject: Re: [PATCH -V2 4/5] ext4: Use both hi and lo bits of the group desc values. Date: Fri, 21 Nov 2008 11:53:29 -0600 Message-ID: <4926F599.5040605@redhat.com> References: <1227285875-18011-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1227285875-18011-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1227285875-18011-3-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1227285875-18011-4-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <4926F00D.6030403@redhat.com> <20081121174110.GH11212@skywalker> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Coly Li , cmm@us.ibm.com, tytso@mit.edu, linux-ext4@vger.kernel.org To: "Aneesh Kumar K.V" Return-path: Received: from mx2.redhat.com ([66.187.237.31]:51315 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752668AbYKURx6 (ORCPT ); Fri, 21 Nov 2008 12:53:58 -0500 In-Reply-To: <20081121174110.GH11212@skywalker> Sender: linux-ext4-owner@vger.kernel.org List-ID: Aneesh Kumar K.V wrote: > On Fri, Nov 21, 2008 at 11:29:49AM -0600, Eric Sandeen wrote: >> Aneesh Kumar K.V wrote: >>> Rename the lower bits with suffix _lo and add helper >>> to access the values. Also rename bg_itable_unused_hi >>> to bg_pad as in e2fsprogs. bg_itable_unused_hi is never >>> used before >> Maybe you can add info about under which circumstances (what sort of >> fielsystem geometry) the hi bits are needed? And the failure mode when >> we don't use them, if that's known? > > Coly actually said it was added for inode reservation. But he agreed to > drop the high bits now and add them later once the performance issue > with the patch is addressed. > > -aneesh Ok, and for the rest? (free_blocks, free_inodes) - I guess these are only needed for > 2^32 block filesystems? Thanks, -eric