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=-3.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 6B64CC4363A for ; Thu, 29 Oct 2020 13:48:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 12E6020809 for ; Thu, 29 Oct 2020 13:48:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="FwRfxyuq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727729AbgJ2Nss (ORCPT ); Thu, 29 Oct 2020 09:48:48 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:28597 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727692AbgJ2Nsr (ORCPT ); Thu, 29 Oct 2020 09:48:47 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1603979326; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=o+6ALnmfHcbX2Kh97Sk3d/ZU9yuOlfGICNtafCoGnYo=; b=FwRfxyuqLngzLRAeP8SufhMFnGhhO/SWP2rK/tRciVewtCn5NwZOo2In8VSxkbC1L/gnD7 DX+FFOSasaoOUFGVjqB3m0fsClqYBGI5ZEfZIp8Iidv5piLq+nR9tARvHvu9nHKwZSjh6z tSnoSvt5WpUflYbvcFf2+NdVcbpN7Jo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-317-RccU4qHMN-6y7QVzvonbrQ-1; Thu, 29 Oct 2020 09:48:40 -0400 X-MC-Unique: RccU4qHMN-6y7QVzvonbrQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8E23A1902EA4; Thu, 29 Oct 2020 13:48:38 +0000 (UTC) Received: from ovpn-66-212.rdu2.redhat.com (ovpn-66-212.rdu2.redhat.com [10.10.66.212]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1705560C17; Thu, 29 Oct 2020 13:48:37 +0000 (UTC) Message-ID: <50aea6567bbdf89e03d50820c19cfb16bb764338.camel@redhat.com> Subject: Re: [PATCH] powerpc/smp: Move rcu_cpu_starting() earlier From: Qian Cai To: paulmck@kernel.org, Michael Ellerman Cc: Peter Zijlstra , Benjamin Herrenschmidt , Paul Mackerras , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Date: Thu, 29 Oct 2020 09:48:36 -0400 In-Reply-To: <20201029003127.GJ3249@paulmck-ThinkPad-P72> References: <20201028182334.13466-1-cai@redhat.com> <87lffpx598.fsf@mpe.ellerman.id.au> <20201029003127.GJ3249@paulmck-ThinkPad-P72> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2020-10-28 at 17:31 -0700, Paul E. McKenney wrote: > On Thu, Oct 29, 2020 at 11:09:07AM +1100, Michael Ellerman wrote: > > Qian Cai writes: > > > The call to rcu_cpu_starting() in start_secondary() is not early enough > > > in the CPU-hotplug onlining process, which results in lockdep splats as > > > follows: > > > > Since when? > > What kernel version? > > > > I haven't seen this running CPU hotplug tests with PROVE_LOCKING=y on > > v5.10-rc1. Am I missing a CONFIG? > > My guess would be that adding CONFIG_PROVE_RAW_LOCK_NESTING=y will > get you some splats. Well, I don't have that set, so it should be CONFIG_PROVE_RCU_LIST=y. Anyway, this is .config to reproduce on Power9 NV: https://cailca.coding.net/public/linux/mm/git/files/master/powerpc.config