From: Hugh Dickins Subject: Re: Boot failure with ext2 and initrds Date: Thu, 16 Nov 2006 16:26:02 +0000 (GMT) Message-ID: References: <20061114014125.dd315fff.akpm@osdl.org> <20061114184919.GA16020@skynet.ie> <20061114113120.d4c22b02.akpm@osdl.org> <20061115214534.72e6f2e8.akpm@osdl.org> <455C0B6F.7000201@us.ibm.com> <20061115232228.afaf42f2.akpm@osdl.org> <1163666960.4310.40.camel@localhost.localdomain> <20061116011351.1401a00f.akpm@osdl.org> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: cmm@us.ibm.com, Mel Gorman , "Martin J. Bligh" , linux-kernel@vger.kernel.org, "linux-ext4@vger.kernel.org" Return-path: Received: from extu-mxob-1.symantec.com ([216.10.194.28]:4301 "EHLO extu-mxob-1.symantec.com") by vger.kernel.org with ESMTP id S1424278AbWKPQZr (ORCPT ); Thu, 16 Nov 2006 11:25:47 -0500 Received: from balaton.wat.veritas.com([10.10.97.7]) (2641 bytes) by megami.veritas.com via sendmail with P:esmtp/R:smart_host/T:smtp (sender: ) id for ; Thu, 16 Nov 2006 08:25:45 -0800 (PST) (Smail-3.2.0.101 1997-Dec-17 #15 built 2001-Aug-30) To: Andrew Morton In-Reply-To: <20061116011351.1401a00f.akpm@osdl.org> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Thu, 16 Nov 2006, Andrew Morton wrote: > On Thu, 16 Nov 2006 00:49:20 -0800 > Mingming Cao wrote: > > > That does not explain the repeated reservation window add and remove > > behavior Huge has reported. > > I spent quite some time comparing with ext3. I'm a bit stumped and I'm > suspecting that the simplistic porting the code is now OK, but something's > just wrong. > > I assume that the while (1) loop in ext3_try_to_allocate_with_rsv() has > gone infinite. I don't see why, but more staring is needed. Just to report that similar tests on three machines have each run for 20 hours so far without any such infinite loop reoccurring. Well, I broke off the x86_64 for a couple of hours: wondered if I'd got confused, forgotten to "rmmod ext2" at one stage, and saw that behaviour with my simple "ext2fs_blk_t ret_block" patch, rather than your more extensive patch to ext2_new_blocks() that I'd believed I was testing. I didn't give it long enough to be conclusive, but the problem didn't show up with that either, so I've gone back to testing with yours. I'd have kept the hang around for longer if I'd guessed it would be hard to reproduce, and that it would be puzzling even to you: sorry. kdb is in, if it comes again I can peer at it more closely. Hugh