From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from avasout-peh-004.plus.net (avasout-peh-004.plus.net [212.159.14.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5C40714D28A for ; Fri, 26 Jul 2024 22:41:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=212.159.14.20 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722033663; cv=none; b=kdn40+6XOyBkVeJgLvFjz6uUfc2sEo1gxAd9FU6T2SAJHVoEPCvPD/BID7E8k5ngSF99Y+UtnVctsk7Bl+76oRJlsc/c4q+5LyY5e1fuAHbOH2jJsbk71XQ80iUpFSEjO3Ie6wnQScoBTzEUtcw94BZVcKOLO00uq+f8c+58Tq4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722033663; c=relaxed/simple; bh=nbxyhmvQwGBMGN3M9d5yxz7d/Rlmkv1KKZqilRx85cg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dJEQFAnRPj1Ap0+kCOP6aZsuiONCBjHdMaSkvdegeS5DRS0kp9Bgpd6BuColFkIUG2A+k/Gu77QOtLCRlT6X5/nTafS0bqwud0EOvCwe2himGEB2FXMp6sIqegQgo4fBxGS7KvcsXFV9qufVj3v/pRfypGLj6E9QRFf9qAgXBKM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=durendal.co.uk; spf=none smtp.mailfrom=durendal.co.uk; arc=none smtp.client-ip=212.159.14.20 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=durendal.co.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=durendal.co.uk Received: from localhost ([146.198.41.26]) by smtp with ESMTPA id XTcFsLcsbX9c9XTcGsAjGg; Fri, 26 Jul 2024 23:40:52 +0100 X-Clacks-Overhead: "GNU Terry Pratchett" X-CM-Score: 0.00 X-CNFS-Analysis: v=2.4 cv=NPx2+F6g c=1 sm=1 tr=0 ts=66a425f4 a=uPaVN7U6Dr8slOeZeejB6w==:117 a=uPaVN7U6Dr8slOeZeejB6w==:17 a=kj9zAlcOel0A:10 a=UpoIEAoSAAAA:8 a=E8U297PRLMU9RVS8rI0A:9 a=CjuIK1q_8ugA:10 a=i2QCTZlBeuS6jn7WOjAa:22 X-AUTH: gnulinux@:2500 Date: Fri, 26 Jul 2024 23:40:47 +0100 From: Rob To: Thomas Gleixner Cc: Christian Heusel , Borislav Petkov , regressions@lists.linux.dev, x86@kernel.org, Joerg Roedel Subject: Re: [REGRESSION][BISECTED] Early boot hangs since f0551af02130 Message-ID: References: <361b2ba5-7fc3-4e9a-af63-adfd4bc20304@heusel.eu> <20240723120246.GBZp-b5nHHT0BWmKMZ@fat_crate.local> <5e08cab0-c6b5-4169-8d42-ddb0ffb4a6c9@heusel.eu> <20240725105029.GAZqIt9aLsIaG7JqN5@fat_crate.local> <12df8b45-6100-4c8b-b82a-a6a75bed2e05@heusel.eu> <87a5i4whoz.ffs@tglx> Precedence: bulk X-Mailing-List: regressions@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: X-CMAE-Envelope: MS4xfCol3hvb9RPdjTEhq+DC+CcfdNVg2UAeP3dmfVHTUtb00Zb8yQ7JSCpjkF3ZE1w58kR3A/7RPRTESxalCgchjj24xZ6Isivz13RanBvuppwFHeIEQiWB 6faBPwQvmYJRmzpNBNBw4wU0ESAYysADT/U1JGDoBuNv6zb1ME2+HSVZoKICYpiOXSF8dWxOCzX18Q== * Rob (rob@durendal.co.uk) wrote: >>So in theory the same problem should happen with a pre 6.9 kernel >>and 'nr_cpus=4' on the kernel command line. Can you please verify? > >Confirmed, 6.6.40-2-lts with 'nr_cpus=4' hangs > >>Another data point to be evaluated is whether booting the unmodified >>6.10+ kernel with 'nointremap' instead of 'iommu=off' on the command >>line makes the machine boot as well. > >linux-mainline 6.10-1.1 with 'nointremap' boots I have also tested on the non-patched mainline version 6.10 with 'nointremap' and it also boots Kind regards, Rob > >>... connect that machine over serial ... > >Unfortunately I don't have the hardware for this > >Kind regards, > >Rob > > >* Thomas Gleixner (tglx@linutronix.de) wrote: >>On Fri, Jul 26 2024 at 00:01, Christian Heusel wrote: >>>Sorry for causing some confusion on that part and I hope the above >>>outputs help with debugging this issue! >> >>Not really. The issue is completely unclear and nothing makes any sense >>here. >> >>The only difference is the resulting number of possible CPUs. >> >>[ 0.026516] CPU topo: Allowing 4 present CPUs plus 12 hotplug CPUs >> >>versus: >> >>[ 0.025251] CPU topo: Allowing 4 present CPUs plus 0 hotplug CPUs >> >>which really should not make any difference because the 1300X has only 4 >>CPUs. >> >>So the bisected commit is the messenger for some other problem >>presumably in the IOMMU area which is just papered over when there are >>12 possible hotplug CPUs enumerated. >> >>So in theory the same problem should happen with a pre 6.9 kernel and >>'nr_cpus=4' on the kernel command line. Can you please verify? >> >>Another data point to be evaluated is whether booting the unmodified >>6.10+ kernel with 'nointremap' instead of 'iommu=off' on the command >>line makes the machine boot as well. >> >>Thanks, >> >> tglx > >-- >Rob Newcater -- Rob Newcater