From patchwork Tue Apr 26 20:48:44 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Pitre X-Patchwork-Id: 66732 Delivered-To: patch@linaro.org Received: by 10.140.93.198 with SMTP id d64csp1827255qge; Tue, 26 Apr 2016 13:48:53 -0700 (PDT) X-Received: by 10.66.75.97 with SMTP id b1mr6546249paw.54.1461703733733; Tue, 26 Apr 2016 13:48:53 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id a1si457433pfb.126.2016.04.26.13.48.53; Tue, 26 Apr 2016 13:48:53 -0700 (PDT) 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 S1752889AbcDZUsv (ORCPT + 29 others); Tue, 26 Apr 2016 16:48:51 -0400 Received: from mail-qk0-f176.google.com ([209.85.220.176]:34510 "EHLO mail-qk0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752348AbcDZUst (ORCPT ); Tue, 26 Apr 2016 16:48:49 -0400 Received: by mail-qk0-f176.google.com with SMTP id r184so10740398qkc.1 for ; Tue, 26 Apr 2016 13:48:48 -0700 (PDT) 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=FW07W3LLyxPaCxQWj/Aa/UsreQrICdFDhDyratDfcqc=; b=UWgoyKsYFTxi8JzXap9p+6E2L/1zaVWpxyi8Q33+PNzsBC40OxM1FMEzGwtflD6FXx xqQdoqXNCUUyizVDaGvIZaCnhYDpNCWReAtYnDJ603pfWWEqbQLki6RHNuqLKGLrJcNI y54uFrWlCgVzf/l7QD9NaDi+aqgbD69WBcbTM= 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=FW07W3LLyxPaCxQWj/Aa/UsreQrICdFDhDyratDfcqc=; b=Nd52OgXRLOVtwECiNR7c4FclXycuBFhHg/5AgKf0S6J9QC/u83P2CVLVHUY/8A9eDE K3jKB66FyCGKa7hzkzD/0oLjiZ5J4pTJwBfhJMopUwKsKqUyCfz3tf0NcvduxHvwJ+Iu JfNjeZt6DNKq+JQxfBNOMAX5gyo5wDcGt8Zfww5HThBdNnlh2buXSuw1Tzh2nfIzm+r1 7TVa/CH55y1yJ4I5TiaecsWRQB0f3I4+IxsLth2LgmKfGQc1yjkiR3wgnxo+/bFX2AA9 Akip0H6b72kecm70Oe3+95TGWyqqXI8R3+q+W7VnZaiDDoQrO9ERUIGHzzKofKuHaG1e QqAA== X-Gm-Message-State: AOPr4FX5lpMumMHDuZaxgskN6IXk8VM9jpQYv3eC27tcwOSGkpcIxEs6JJktEvB5MpVSrnfG X-Received: by 10.55.81.87 with SMTP id f84mr4764823qkb.10.1461703728104; Tue, 26 Apr 2016 13:48:48 -0700 (PDT) Received: from xanadu.home ([2607:fa48:6e39:d410:feaa:14ff:fea7:ed77]) by smtp.gmail.com with ESMTPSA id z64sm125309qkb.29.2016.04.26.13.48.45 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 26 Apr 2016 13:48:46 -0700 (PDT) Date: Tue, 26 Apr 2016 16:48:44 -0400 (EDT) From: Nicolas Pitre To: Stephen Rothwell , Michal Marek cc: linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, Jens Axboe , Randy Dunlap Subject: Re: linux-next: build failure after merge of the block tree In-Reply-To: <20160427011825.06c64502@canb.auug.org.au> Message-ID: References: <20160426133812.366dc031@canb.auug.org.au> <571F6D59.8040402@suse.cz> <20160427011825.06c64502@canb.auug.org.au> 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, 27 Apr 2016, Stephen Rothwell wrote: > Hi Nicolas, > > On Tue, 26 Apr 2016 10:40:57 -0400 (EDT) Nicolas Pitre wrote: > > > > If you can reproduce this build failure, could you try a make mrproper > > and attempt it again? I, too, would like to find an explanation and a > > way to reproduce. > > I reset my build tree to commit 9d67df654092 ("Merge remote-tracking > branch 'block/for-next'") and the build failed with: > > ERROR: ".local_clock" [drivers/vhost/vhost_net.ko] undefined! > ERROR: ".local_clock" [drivers/misc/cxl/cxl.ko] undefined! > > :-( > > So I did a "make mrproper" and did the build again. > > That built correctly. > [...] OK! After digging and diffing through 750 megabytes of make debug logs I finally found the explanation. The if_changed directive is useless against phony targets. @Stephen: could you replace the revert with the patch below in your tree? @Michal: could you fold the patch below into commit 2441e78b19 in your tree? diff --git a/Makefile b/Makefile index ca46af5cc0..3a7b9a93b2 100644 --- a/Makefile +++ b/Makefile @@ -953,7 +953,7 @@ include/generated/autoksyms.h: FORCE cmd_link-vmlinux = $(CONFIG_SHELL) $< $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) quiet_cmd_link-vmlinux = LINK $@ -vmlinux: scripts/link-vmlinux.sh vmlinux_prereq FORCE +vmlinux: scripts/link-vmlinux.sh vmlinux_prereq $(vmlinux-deps) FORCE +$(call if_changed,link-vmlinux) # Build samples along the rest of the kernel