From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mp0 ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by ms11 with LMTPS id iPCEEWG8pV/AOgAA0tVLHw (envelope-from ) for ; Fri, 06 Nov 2020 21:13:05 +0000 Received: from aspmx1.migadu.com ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by mp0 with LMTPS id QGN3DWG8pV9YDQAA1q6Kng (envelope-from ) for ; Fri, 06 Nov 2020 21:13:05 +0000 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by aspmx1.migadu.com (Postfix) with ESMTPS id 0DF9A94042B for ; Fri, 6 Nov 2020 21:13:05 +0000 (UTC) Received: from localhost ([::1]:60752 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kb92d-0004hj-Vm for larch@yhetil.org; Fri, 06 Nov 2020 16:13:04 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:59282) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kb92Q-0004hZ-1r for guix-devel@gnu.org; Fri, 06 Nov 2020 16:12:50 -0500 Received: from world.peace.net ([64.112.178.59]:52252) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kb92N-0000P6-N3; Fri, 06 Nov 2020 16:12:49 -0500 Received: from mhw by world.peace.net with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kb92A-0003Yc-OO; Fri, 06 Nov 2020 16:12:34 -0500 From: Mark H Weaver To: Ludovic =?utf-8?Q?Court=C3=A8s?= , John Soo Subject: Re: RFC: subcommand to pause/resume builds In-Reply-To: <87zh3yczss.fsf@gnu.org> References: <87r1pbzixl.fsf@asu.edu> <87zh3yczss.fsf@gnu.org> Date: Fri, 06 Nov 2020 16:11:54 -0500 Message-ID: <87d00qb362.fsf@netris.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=64.112.178.59; envelope-from=mhw@netris.org; helo=world.peace.net X-detected-operating-system: by eggs.gnu.org: First seen = 2020/11/06 16:12:36 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: guix-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: guix-devel@gnu.org Errors-To: guix-devel-bounces+larch=yhetil.org@gnu.org Sender: "Guix-devel" X-Scanner: ns3122888.ip-94-23-21.eu Authentication-Results: aspmx1.migadu.com; dkim=none; dmarc=none; spf=pass (aspmx1.migadu.com: domain of guix-devel-bounces@gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=guix-devel-bounces@gnu.org X-Spam-Score: -1.01 X-TUID: vR3xVQQAGKBA Hi Ludovic, Ludovic Court=C3=A8s writes: > Last, you=E2=80=99d need to send SIGTSTP to the whole process group of the > build, like so (I think, haven=E2=80=99t tried): > > sudo kill -TSTP -123 > > where 123 is the =E2=80=9CSessionPID=E2=80=9D shown by =E2=80=98guix proc= esses=E2=80=99. However, doing > so may affect build results: processes in the build environment might > handle SIGTSTP specially, which can have side effects. It=E2=80=99s an > observable action. What's the rationale for using SIGTSTP instead of SIGSTOP here? FWIW, on a few occasions I've paused builds by sending SIGSTOP to the relevant process group, and later SIGCONT, and it has worked for me. As I recall, I've done this while building rust, webkitgtk, and icecat. However, I suspect that if I paused a build while running tests, the test suite might ultimately fail due to a "timeout". > Conclusion: I don=E2=80=99t think we can implement this reliably. Agreed. Thanks, Mark