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 ECC3CEB64D8 for ; Wed, 14 Jun 2023 14:54:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236347AbjFNOyD (ORCPT ); Wed, 14 Jun 2023 10:54:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38856 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244810AbjFNOx4 (ORCPT ); Wed, 14 Jun 2023 10:53:56 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 85C0B1981 for ; Wed, 14 Jun 2023 07:53:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=vQIh9rt3ny8U0TLt3kcLM40HArnjCLKdcZhHwk4yddE=; b=m6NtQ5Ep2yYq1HjciTcJZrETax NaW4ckO0c8Aq81U8Vp7+yFzK3A6j1heYW+bTPDlh+xbhxmcoB49itjMxbW/MCoWQ/guuOFsaFw7ge 4rpbjbf5aHBiSzvmRvjCizD5w9RgAWFFlJaItoXxo9yipQbEBrDVefkAyjrrJ9y1v8/xMSm9gbnoP L8malMIo4JVQM/6BhbDaCezsz/kPaGlVxaaAOL1H5NPsn2WVI47JlETirC0vtan8zmDPHvSOLmcnP OLBuPNdS3MP0ntP7KppRXCbAGyWGnI/Eu1vbPBFVbM0OvLnBH6QWcMC2Aoa3wY43v8B/FPHm2b1TK EQjnJhMA==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1q9Rsb-006RRx-7r; Wed, 14 Jun 2023 14:53:49 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id DB5B0300188; Wed, 14 Jun 2023 16:53:48 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 6EEB02080F556; Wed, 14 Jun 2023 16:53:48 +0200 (CEST) Date: Wed, 14 Jun 2023 16:53:48 +0200 From: Peter Zijlstra To: "Richard W.M. Jones" Cc: Aaron Thompson , linux-kernel@vger.kernel.org Subject: Re: printk.time causes rare kernel boot hangs Message-ID: <20230614145348.GB1640563@hirez.programming.kicks-ass.net> References: <20230613134105.GA10301@redhat.com> <20230614092158.GF1639749@hirez.programming.kicks-ass.net> <20230614094522.GA7636@redhat.com> <20230614103011.GL7912@redhat.com> <20230614103953.GM7912@redhat.com> <20230614113536.GJ1639749@hirez.programming.kicks-ass.net> <20230614125320.GA1640563@hirez.programming.kicks-ass.net> <20230614130348.GF7636@redhat.com> <20230614130945.GK1639749@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230614130945.GK1639749@hirez.programming.kicks-ass.net> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 14, 2023 at 03:09:45PM +0200, Peter Zijlstra wrote: > On Wed, Jun 14, 2023 at 02:03:48PM +0100, Richard W.M. Jones wrote: > > On Wed, Jun 14, 2023 at 02:53:20PM +0200, Peter Zijlstra wrote: > > > Ooooh, what qemu version do you have? There were some really dodgy > > > reports all around self modifying code, all reported on 7.2, that seems > > > to have gone away with 8. > > > > > Now, all of them were using TCG, and I think you're using KVM. > > > > I'm using qemu-system-x86-8.0.0-4.fc39.x86_64 with KVM. The host > > kernel is 6.4.0-0.rc5.41.fc39.x86_64. > > > > > I've at least 36000 cycles and still nothing :-(, let me go try your > > > .config. > > > > I can definitely reproduce this with your config (but AMD host), so > > that's odd. Let me try with Intel hardware and your config. You > > really should see this with only a few thousands iterations. > > Yeah, I'm running on some ancient ivb-ep, let me try on the alderlake. I > don't really have AMD machines at hand :-/ Using v6.4-rc6-37-gb6dad5178cea, and 36000+ cycles on the ADL (affine to big cores) later and nothing :-( Clearly I'm doing something wrong.