From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 86793 invoked by alias); 16 Dec 2015 17:06:31 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 86783 invoked by uid 89); 16 Dec 2015 17:06:31 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.7 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy= X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Wed, 16 Dec 2015 17:06:30 +0000 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (Postfix) with ESMTPS id EA880693C3; Wed, 16 Dec 2015 17:06:28 +0000 (UTC) Received: from localhost.localdomain (ovpn-113-83.phx2.redhat.com [10.3.113.83]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id tBGH6Sk2022498; Wed, 16 Dec 2015 12:06:28 -0500 Subject: Re: [PATCH, PR67627][RFC] broken libatomic multilib parallel build To: Szabolcs Nagy , "gcc-patches@gcc.gnu.org" References: <56618964.3020209@arm.com> Cc: Marcus Shawcroft From: Jeff Law Message-ID: <56719A14.10502@redhat.com> Date: Wed, 16 Dec 2015 17:06:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <56618964.3020209@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2015-12/txt/msg01639.txt.bz2 On 12/04/2015 05:39 AM, Szabolcs Nagy wrote: > As described in pr other/67627, the all-multi target can be > built in parallel with the %_.lo targets which generate make > dependencies that are parsed during the build of all-multi. > > gcc -MD does not generate the makefile dependencies in an > atomic way so make can fail if it concurrently parses those > half-written files. > (not observed on x86, but happens on arm native builds.) > > this workaround forces all-multi to only run after the *_.lo > targets are done, but there might be a better solution using > automake properly. (automake should know about the generated > make dependency files that are included into the makefile so > no manual tinkering is needed to get the right build order, > but i don't know how to do that.) > > 2015-12-04 Szabolcs Nagy > > PR other/67627 > * Makefile.am (all-multi): Add dependency. > * Makefile.in: Regenerate. So looking at the patch, it looks like you're adding a dependency in Makefile.am to pass it through to Makefile.in, which is fine. So I think you just need to replicate that fix across the other libraries which have this problem. jeff