From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: read-process-output-max (was: Emacs HTTP libraries) Date: Wed, 31 Mar 2021 20:13:32 +0300 Message-ID: <83zgyjgsar.fsf@gnu.org> References: <87r1jxd3d8.fsf@gnu.org> <8e549f23-db75-2ef1-4399-0fb52e5efa6f@gnu.org> <87zgykn5qc.fsf@gnus.org> <83sg4ckbfw.fsf@gnu.org> <87mtukn463.fsf@gnus.org> <83o8f0kaoj.fsf@gnu.org> <83mtukk9b3.fsf@gnu.org> <2e968b98-2264-03e7-d0b2-5570c94b6fb7@gmail.com> <838s64k3xk.fsf@gnu.org> <8260671e-df0a-e471-79fb-82f80e11696a@gmail.com> <837dlok1zj.fsf@gnu.org> <83zgyjj1yf.fsf@gnu.org> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="6135"; mail-complaints-to="usenet@ciao.gmane.io" Cc: cpitclaudel@gmail.com, emacs-devel@gnu.org, raman@google.com To: Stefan Monnier Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Wed Mar 31 19:14:47 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 1lReQY-0001SF-Qz for ged-emacs-devel@m.gmane-mx.org; Wed, 31 Mar 2021 19:14:46 +0200 Original-Received: from localhost ([::1]:38418 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lReQX-0003Wu-Ij for ged-emacs-devel@m.gmane-mx.org; Wed, 31 Mar 2021 13:14:45 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:58414) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lRePV-00034O-R2 for emacs-devel@gnu.org; Wed, 31 Mar 2021 13:13:41 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:36178) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lRePU-0000C6-RE; Wed, 31 Mar 2021 13:13:40 -0400 Original-Received: from 84.94.185.95.cable.012.net.il ([84.94.185.95]:4794 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1lRePT-0002W3-Be; Wed, 31 Mar 2021 13:13:39 -0400 In-Reply-To: (message from Stefan Monnier on Wed, 31 Mar 2021 12:01:35 -0400) 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:267223 Archived-At: > From: Stefan Monnier > Cc: "T.V Raman" , cpitclaudel@gmail.com, > emacs-devel@gnu.org > Date: Wed, 31 Mar 2021 12:01:35 -0400 > > I understand there is a per-chunk overhead which pushes towards a higher > value, but I'm not sure what factors are pushing towards smaller values. Values larger that some threshold will cause us use malloc instead of alloca, that's one reason to use smaller buffers for performance reasons. Another potential issue, in programs that display the arriving stuff as it is received, is that showing the text in small chunks is generally better (UX-wise) than blasting a 1MB chunk of text to the screen in one go. > The docstring seems to strongly recommend not to increase it, so > I suspect there's a much stronger reason that "not be wasteful" in play. The effect of the value was never studied in detail, and so the optimal value could be different from the default. The doc string says what it says to prevent people from getting themselves into trouble when they don't really need to change the value for their application: after all, the default value was used for many years, and should be considered safe enough.