From patchwork Wed Nov 30 22:41:58 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Pitre X-Patchwork-Id: 85927 Delivered-To: patch@linaro.org Received: by 10.182.112.6 with SMTP id im6csp565874obb; Wed, 30 Nov 2016 14:43:07 -0800 (PST) X-Received: by 10.84.209.227 with SMTP id y90mr77930904plh.111.1480545787667; Wed, 30 Nov 2016 14:43:07 -0800 (PST) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id b5si35531307pgi.172.2016.11.30.14.43.07; Wed, 30 Nov 2016 14:43:07 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758908AbcK3Wm6 (ORCPT + 25 others); Wed, 30 Nov 2016 17:42:58 -0500 Received: from mail-qt0-f178.google.com ([209.85.216.178]:34629 "EHLO mail-qt0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752330AbcK3Wm4 (ORCPT ); Wed, 30 Nov 2016 17:42:56 -0500 Received: by mail-qt0-f178.google.com with SMTP id n6so203605066qtd.1 for ; Wed, 30 Nov 2016 14:42:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:in-reply-to:message-id:references :user-agent:mime-version; bh=aBeo9GJ45ghCjIdE/hv72xFwb2pDktHRp5nPOQwmdZc=; b=Hj+1Nf1ksGCAlU4deGOyYNvUNuY/Z3icGyvXqlgsIkU9cOL6bLjBqLDp1beMUu5WEN 9u+L0VwEzN0PwTbpq9Xvfdcj/zef559XrzJMwCib/G6G7RK0Vbwd02i4DL6D4zhx2EsD ZCie6UdZAj9M6A7IHkZ5LlC7y/WwCLIPje8D4= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:date:from:to:cc:subject:in-reply-to:message-id :references:user-agent:mime-version; bh=aBeo9GJ45ghCjIdE/hv72xFwb2pDktHRp5nPOQwmdZc=; b=gTjCxqxPAmBfC+3FVA9X1lR5zueBdKIruqCVcwlLlWULsImngACNIV5TiC4q38hnQa 1yRB/vfieMBuNVh/U6RW8BRYw4DIoozyOyETz4BHFHEqGn/kWEaID35sFcSBs2vSmcWs 2K7wm1Rsb2h6JWvmpmE4chpSPHI21sFS5EFD+Vgdi72jnIJ1V2ulCSXhadLhwTUyQMxR duMZeuZ2vaFJe6+oawx4KMam7DQmWXOnKJEjr3M7RoQJq36Uo+J15SnimqvMSo7wX2Ve mwawzJenN7Rr5CbZMpYuGhGlHn6KuiJ+AzSIoIZiiPOX32n2za+iEajUQQDrRpA271fB F/0w== X-Gm-Message-State: AKaTC015Hie9BHjFyjWweAxWRO5FcDerLG/25S5rz4mVlAswbPvP/stE0NgiV2bj0nkfndTS X-Received: by 10.237.40.38 with SMTP id r35mr31492769qtd.0.1480545719498; Wed, 30 Nov 2016 14:41:59 -0800 (PST) Received: from xanadu.home ([2607:fa48:6e39:d410:feaa:14ff:fea7:ed77]) by smtp.gmail.com with ESMTPSA id o68sm26653997qka.29.2016.11.30.14.41.58 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 30 Nov 2016 14:41:59 -0800 (PST) Date: Wed, 30 Nov 2016 17:41:58 -0500 (EST) From: Nicolas Pitre To: Linus Torvalds cc: Prarit Bhargava , Jarod Wilson , Linux Kernel Mailing List , Tony Luck , zarniwhoop73@googlemail.com, Linux Kbuild mailing list Subject: Re: Odd build breakage in 4.9-rc7 In-Reply-To: Message-ID: References: <20161130172435.GG8563@redhat.com> <583F1A5A.7040708@redhat.com> <583F1F6A.5010307@redhat.com> User-Agent: Alpine 2.20 (LFD 67 2015-01-07) MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 30 Nov 2016, Linus Torvalds wrote: > On Wed, Nov 30, 2016 at 10:50 AM, Prarit Bhargava wrote: > > > > It comes back. The steps to reproduce this are: > > > > 1. checkout latest linux.git > > 2. make -j112 > > > > (IOW, it occurs 100% of the time for me on a clean tree.) I don't have access to such hardware where -j112 could ever make sense. :-) In other words, I can't reproduce regardless of the -j value I try. > I suspect it's not new, it's just that you are able to hit the timing > just right (and the new include presumable makes that just be much > easier). Here's the best fix I can think of. I can't convince myself any other location would be 100% safe. Obviously I can't confirm if this actually fixes anything. ----- >8 Subject: kbuild: make sure autoksyms.h exists early Some people are able to trigger a race where autoksyms.h is used before its empty version is even created. Let's create it at the same time as the directory holding it is created. Signed-off-by: Nicolas Pitre Tested-by: Prarit Bhargava Tested-by: Jarod Wilson diff --git a/Makefile b/Makefile index 694111b43c..9f9c3b577c 100644 --- a/Makefile +++ b/Makefile @@ -1019,8 +1019,6 @@ prepare2: prepare3 prepare-compiler-check outputmakefile asm-generic prepare1: prepare2 $(version_h) include/generated/utsrelease.h \ include/config/auto.conf $(cmd_crmodverdir) - $(Q)test -e include/generated/autoksyms.h || \ - touch include/generated/autoksyms.h archprepare: archheaders archscripts prepare1 scripts_basic diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile index ebced77deb..90a091b6ae 100644 --- a/scripts/kconfig/Makefile +++ b/scripts/kconfig/Makefile @@ -35,6 +35,8 @@ nconfig: $(obj)/nconf silentoldconfig: $(obj)/conf $(Q)mkdir -p include/config include/generated + $(Q)test -e include/generated/autoksyms.h || \ + touch include/generated/autoksyms.h $< $(silent) --$@ $(Kconfig) localyesconfig localmodconfig: $(obj)/streamline_config.pl $(obj)/conf