From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Torsten Kaiser" Subject: Re: 2.6.24-rc6-mm1 Date: Sat, 5 Jan 2008 23:10:17 +0100 Message-ID: <64bb37e0801051410p39746295oab4dad438943372@mail.gmail.com> References: <64bb37e0801040223q17a76565k3c7667a197403ce5@mail.gmail.com> <20080104133031.GA3329@ff.dom.local> <64bb37e0801040721p57ff3d54wc3de00546d1d2ff1@mail.gmail.com> <20080105000700.GA3224@ami.dom.local> <64bb37e0801050001x65b104bdl5a68c731b3656d17@mail.gmail.com> <20080105101327.GA3103@ami.dom.local> <64bb37e0801050652t7568e438uf93208601df84ef6@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "Herbert Xu" , "Andrew Morton" , linux-kernel@vger.kernel.org, "Neil Brown" , "J. Bruce Fields" , netdev@vger.kernel.org, "Tom Tucker" To: "Jarek Poplawski" Return-path: Received: from py-out-1112.google.com ([64.233.166.183]:32425 "EHLO py-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756710AbYAEWKT (ORCPT ); Sat, 5 Jan 2008 17:10:19 -0500 Received: by py-out-1112.google.com with SMTP id u52so11790879pyb.10 for ; Sat, 05 Jan 2008 14:10:18 -0800 (PST) In-Reply-To: <64bb37e0801050652t7568e438uf93208601df84ef6@mail.gmail.com> Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: On Jan 5, 2008 3:52 PM, Torsten Kaiser wrote: > On Jan 5, 2008 11:13 AM, Jarek Poplawski wrote: > > On Sat, Jan 05, 2008 at 09:01:02AM +0100, Torsten Kaiser wrote: > > > On Jan 5, 2008 1:07 AM, Jarek Poplawski wrote: > > > > I think it would be easier just to start with this working -rc6 and > > > > simply check if we have 'right' suspects, so: git-net.patch and > > > > git-nfsd.patch from -mm1-broken-out, as suggested by Herbert (I hope, > > > > can compile - otherwise you could try the other way: add the whole -mm > > > > and revert these two). Using current gits could complicate this > > > > "investigation". > > > > > > OK, I will try this... > > still on the todo-list, I had no time to try this yet... working on it... 2.6.24-rc6 + mm-patches up to git.battery (includes git-net and git-netdev-all) worked for 110 packages, then I proclaimed it good. 2.6.24-rc6 + mm-patches up to (including) git.nfsd is currently getting testet (9 packages done...) But the cause of my mail is the following question: Regarding my "iommu-sg-merging-patches are new in -rc3-mm and could be the cause"-suspicion I looked at these patches and came across these hunks: This is removed from arch/x86/lib/bitstr_64.c: -/* Find string of zero bits in a bitmap */ -unsigned long -find_next_zero_string(unsigned long *bitmap, long start, long nbits, int len) -{ - unsigned long n, end, i; - - again: - n = find_next_zero_bit(bitmap, nbits, start); - if (n == -1) - return -1; - - /* could test bitsliced, but it's hardly worth it */ - end = n+len; - if (end > nbits) - return -1; - for (i = n+1; i < end; i++) { - if (test_bit(i, bitmap)) { - start = i+1; - goto again; - } - } - return n; -} This is added to lib/iommu-helper.c: +static unsigned long find_next_zero_area(unsigned long *map, + unsigned long size, + unsigned long start, + unsigned int nr) +{ + unsigned long index, end, i; +again: + index = find_next_zero_bit(map, size, start); + end = index + nr; + if (end > size) + return -1; + for (i = index + 1; i < end; i++) { + if (test_bit(i, map)) { + start = i+1; + goto again; + } + } + return index; +} The old version checks, if find_next_zero_bit returns -1, the new version doesn't do this. Is this intended and can find_next_zero_bit never fail? Hmm... but in the worst case it should only loop forever if I'm reading this right (index = -1 => for-loop counts from 0 to nr, if any bit is set it will jump to "again:" and if the next call to find_next_zero_bit also fails, its an endless loop) So even if this can not explain my bug, could somebody check if this is a real bug or not? Torsten