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 X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 46A8EC432BE for ; Mon, 30 Aug 2021 23:57:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1ED7460F4B for ; Mon, 30 Aug 2021 23:57:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239139AbhH3X6B (ORCPT ); Mon, 30 Aug 2021 19:58:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39164 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233413AbhH3X57 (ORCPT ); Mon, 30 Aug 2021 19:57:59 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5EF56C061575; Mon, 30 Aug 2021 16:57:05 -0700 (PDT) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1630367824; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=II7kr15IK3yVzn+wqs9ggAl0e2ITXLSBVCs7oul256g=; b=UJB1BmN/GLRUpjfKiStlGPks9y33OJXh4aIazBHTPzmvfv4M0prAA4xBlqgXtHMlcWJqgG TEKtGLfHWPJ+CjFYxzc5MNxi61kyqTxOWLpYrs2ahn/t6ZxwMO0sVH+km7MvA2/VEuIF/o 7Td7pNcLWVyGNPMLS6TFZgGwvwUvXz84W78JsohtW/FNIVJV02T8qjb3t6M+r/yQokqsGD U4jTd4p1dr4iOVZP4b92IoB/jL8azc25f9KCrBvph7MX5y1S2DbDyzJyKumyi9A8CoMXhp 8I/e0GmF1PJqZFicaj5ulPla+D18vYEkMcOveENl7v0YgifeAuuJxJUZJTNx3A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1630367824; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=II7kr15IK3yVzn+wqs9ggAl0e2ITXLSBVCs7oul256g=; b=jW+3yxOxWsNazbUV71bYBpQpOtxBxmUYZjDNl9y+QHieHL4Xmr9Bs3f8+Jqt1snWyJG6zp WZpTofMv5RDgh9Dg== To: Guenter Roeck , Linus Torvalds Cc: Linux Kernel Mailing List , Peter Zijlstra , linux-s390@vger.kernel.org, Heiko Carstens , Sven Schnelle Subject: Re: Linux 5.14 In-Reply-To: <87wno2fzbq.ffs@tglx> References: <20210830201225.GA2671970@roeck-us.net> <87wno2fzbq.ffs@tglx> Date: Tue, 31 Aug 2021 01:57:03 +0200 Message-ID: <8735qqfpv4.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 30 2021 at 22:32, Thomas Gleixner wrote: > On Mon, Aug 30 2021 at 13:12, Guenter Roeck wrote: >> On Sun, Aug 29, 2021 at 03:19:23PM -0700, Linus Torvalds wrote: >> So far so good, but there is a brand new runtime warning, seen when booting >> s390 images. >> >> [ 3.218816] ------------[ cut here ]------------ >> [ 3.219010] WARNING: CPU: 1 PID: 0 at kernel/sched/core.c:5779 sched_core_cpu_starting+0x172/0x180 >> [ 3.222992] [<0000000000186e86>] sched_core_cpu_starting+0x176/0x180 >> [ 3.223114] ([<0000000000186dc4>] sched_core_cpu_starting+0xb4/0x180) >> [ 3.223182] [<00000000001963e4>] sched_cpu_starting+0x2c/0x68 >> [ 3.223243] [<000000000014f288>] cpuhp_invoke_callback+0x318/0x970 >> [ 3.223304] [<000000000014f970>] cpuhp_invoke_callback_range+0x90/0x108 >> [ 3.223364] [<000000000015123c>] notify_cpu_starting+0x84/0xa8 >> [ 3.223426] [<0000000000117bca>] smp_init_secondary+0x72/0xf0 >> [ 3.223492] [<0000000000117846>] smp_start_secondary+0x86/0x90 >> >> Commit 3c474b3239f12 ("sched: Fix Core-wide rq->lock for uninitialized >> CPUs") sems to be the culprit. Indeed, the warning is gone after reverting >> this commit. > > The warning is gone, but the underlying S390 problem persists: > > S390 invokes notify_cpu_starting() _before_ updating the topology masks. And interestingly enough that very commit was tested on S390: https://lore.kernel.org/r/yt9dy28o8q0o.fsf@linux.ibm.com Thanks, tglx