From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9E466CA0FE8 for ; Fri, 1 Sep 2023 12:24:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349397AbjIAMYg (ORCPT ); Fri, 1 Sep 2023 08:24:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52602 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243081AbjIAMYg (ORCPT ); Fri, 1 Sep 2023 08:24:36 -0400 Received: from muru.com (muru.com [72.249.23.125]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 45D52D7; Fri, 1 Sep 2023 05:24:33 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTPS id 5DBA1809C; Fri, 1 Sep 2023 12:24:32 +0000 (UTC) Date: Fri, 1 Sep 2023 15:24:31 +0300 From: Tony Lindgren To: Sean Christopherson Cc: Marc Haber , Bagas Sanjaya , linux-kernel@vger.kernel.org, Linux Regressions , Linux KVM , Paolo Bonzini Subject: Re: Linux 6.5 speed regression, boot VERY slow with anything systemd related Message-ID: <20230901122431.GU11676@atomide.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Sean Christopherson [230831 22:07]: > On Tue, Aug 29, 2023, Marc Haber wrote: > > Hi, > > > > On Tue, Aug 29, 2023 at 10:14:23AM -0700, Sean Christopherson wrote: > > > On Tue, Aug 29, 2023, Marc Haber wrote: > > > > Both come from virt-manager, so if the XML helps more, I'll happy to > > > > post that as well. > > > > > > Those command lines are quite different, e.g. the Intel one has two > > > serial ports versus one for the AMD VM. > > > > Indeed? I virt-manager, I don't see a second serial port. In either case, > > only the one showing up in the VM as ttyS0 is being used. But thanks for > > making me look, I discovered that the machine on the Intel host still > > used emulated SCSI instead of VirtIO für the main disk. I changed that. > > > > >Unless Tony jumps in with an > > > idea, I would try massaging either the good or bad VM's QEMU > > > invocation, e.g. see if you can get the AMD VM to "pass" by pulling in > > > stuff from the Intel VM, or get the Intel VM to fail by making its > > > command line look more like the AMD VM. > > > > In Virt-Manager, both machines don't look THAT different tbh. I verified > > the XML and the differences are not big at all. > > > > Do you want me to try different vCPU types? Currently the VM is set to > > "Opteron_G3", would you recommend a different vCPU for the host having a > > "AMD GX-412TC SOC" host CPU? > > I would be surprised if using a different vCPU type fixed anything, but it's not > impossible that it could help. In general, unless someone from the serial driver > side spots an issue, fixing whatever the bug is will likely require a reproducer, > which in turn likely means narrowing down what exactly is unique about your AMD > setup. In other words, if you have cycles to spare, anything you can do to help > isolate the problem would be appreciated. Yes two somewhat minimal qemu command lines for working and failing test case sure would help to debug this. Regards, Tony