Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964913AbWL1EyV (ORCPT ); Wed, 27 Dec 2006 23:54:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964924AbWL1EyV (ORCPT ); Wed, 27 Dec 2006 23:54:21 -0500 Received: from smtp.osdl.org ([65.172.181.25]:58209 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964913AbWL1EyU (ORCPT ); Wed, 27 Dec 2006 23:54:20 -0500 Date: Wed, 27 Dec 2006 20:53:36 -0800 (PST) From: Linus Torvalds To: Gordon Farquharson cc: David Miller , ranma@tdiedrich.de, tbm@cyrius.com, Peter Zijlstra , andrei.popa@i-neo.ro, Andrew Morton , hugh@veritas.com, nickpiggin@yahoo.com.au, arjan@infradead.org, Linux Kernel Mailing List Subject: Re: [PATCH] mm: fix page_mkclean_one In-Reply-To: <97a0a9ac0612272032uf5358c4qf12bf183f97309a6@mail.gmail.com> Message-ID: References: <20061226.205518.63739038.davem@davemloft.net> <20061227.165246.112622837.davem@davemloft.net> <97a0a9ac0612272032uf5358c4qf12bf183f97309a6@mail.gmail.com> 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 Content-Length: 1545 Lines: 40 On Wed, 27 Dec 2006, Gordon Farquharson wrote: > > It is at all suprising that the second offset within a page can be > less than the first offset within a page ? e.g. > > Chunk 260 corrupted (1-1455) (2769-127) No, that just means that it went over to the next page (so you actually had two consecutive pages that weren't written out). That said, your output is very different from mine in another way. You don't have zeroes in your pages, rather the thing seems to have data from the next block (ie the chunk that should have 20 is reported as having 21 etc). You also have your offsets shifted up by one (ie offset 0 looks ok for you, and then you have a strange pattern of corruption at bytes 1...1455 instead of 0..1459. You also seem to have an example of the _earlier_ writes being corrupted, rather than the later ones. For example (but it's also a page-crosser, so maybe that's part of it): Chunk 274 corrupted (1-1455) (2729-87) Expected 18, got 19 Written as (154)11(85) says that block chunk 274 is the corrupt one, but it was written fairly early as #11, and the blocks around it (chunks 273 and 275) were actually written later. For all I know, my test-program is buggy wrt the ordering printouts, though. Did you perhaps change the logic in any way? Linus - 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/