From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Andy Moreton Newsgroups: gmane.emacs.devel Subject: Re: master 2c79a8f 2/2: Use posix_spawn if possible. Date: Sat, 02 Jan 2021 01:12:36 +0000 Message-ID: <861rf4nnuj.fsf@gmail.com> References: <835z4qnhyx.fsf@gnu.org> <83y2hklqhg.fsf@gnu.org> <83wnx4lq3b.fsf@gnu.org> <86k0swut21.fsf@gmail.com> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="19821"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (windows-nt) To: emacs-devel@gnu.org Cancel-Lock: sha1:LL4HgICWtke7fZ56g1F9zKwygU8= Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Jan 02 02:13:27 2021 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kvVTy-00054b-Lr for ged-emacs-devel@m.gmane-mx.org; Sat, 02 Jan 2021 02:13:26 +0100 Original-Received: from localhost ([::1]:38726 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kvVTx-0003IN-Ow for ged-emacs-devel@m.gmane-mx.org; Fri, 01 Jan 2021 20:13:25 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:58274) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kvVTL-0002tH-96 for emacs-devel@gnu.org; Fri, 01 Jan 2021 20:12:47 -0500 Original-Received: from ciao.gmane.io ([116.202.254.214]:35924) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kvVTJ-0001Oh-Qw for emacs-devel@gnu.org; Fri, 01 Jan 2021 20:12:46 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1kvVTG-0004HK-GF for emacs-devel@gnu.org; Sat, 02 Jan 2021 02:12:42 +0100 X-Injected-Via-Gmane: http://gmane.org/ Received-SPF: pass client-ip=116.202.254.214; envelope-from=ged-emacs-devel@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: 5 X-Spam_score: 0.5 X-Spam_bar: / X-Spam_report: (0.5 / 5.0 requ) BAYES_00=-1.9, DKIM_ADSP_CUSTOM_MED=0.001, FORGED_GMAIL_RCVD=1, FREEMAIL_FORGED_FROMDOMAIN=0.249, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.249, NML_ADSP_CUSTOM_MED=0.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:262278 Archived-At: On Fri 01 Jan 2021, Alan Third wrote: > On Fri, Jan 01, 2021 at 11:38:14PM +0000, Andy Moreton wrote: >> On Thu 31 Dec 2020, Philipp Stephani wrote: >> > The annoying thing about this, though, is that it doesn't work on the >> > BSDs (including macOS). For pty processes on those systems we'll have >> > to continue using fork/vfork for the time being. >> > I think that using posix_spawn on GNU/Linux and for non-pty processes >> > is still a significant win, though. >> >> Can I ask why ? You have not yet explained what benefit this change >> brings, and the length of the discussion shows that there are >> difficulties with it. What is improved by using posix_spawn ? > > posix_spawn is supposed to be significantly faster than fork/exec on > macOS and Cygwin. Thanks Alan, useful info. However Philipp started with Linux, so there ought to also be something useful there that motivated these patches. I would be interested to learn what helps on Linux. AndyM