From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Alan Mackenzie Newsgroups: gmane.emacs.devel Subject: Re: Time to merge scratch/correct-warning-pos into master, perhaps? Date: Wed, 26 Jan 2022 19:34:49 +0000 Message-ID: References: <83r18zkmd5.fsf@gnu.org> <835yq9ls7j.fsf@gnu.org> <058b682b11240176288f@heytings.org> <83h79tjd2f.fsf@gnu.org> <058b682b11f58780b580@heytings.org> <83v8y8ij39.fsf@gnu.org> <6a5bb5a08b3d764611f9@heytings.org> <83pmoghuho.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="34122"; mail-complaints-to="usenet@ciao.gmane.io" Cc: mattiase@acm.org, Eli Zaretskii , emacs-devel@gnu.org, larsi@gnus.org, monnier@iro.umontreal.ca To: Gregory Heytings Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Wed Jan 26 20:39:50 2022 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 1nCo8z-0008ka-Ty for ged-emacs-devel@m.gmane-mx.org; Wed, 26 Jan 2022 20:39:49 +0100 Original-Received: from localhost ([::1]:40970 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nCo8y-00031F-UZ for ged-emacs-devel@m.gmane-mx.org; Wed, 26 Jan 2022 14:39:48 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:46806) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nCo4H-0006V8-Ql for emacs-devel@gnu.org; Wed, 26 Jan 2022 14:34:58 -0500 Original-Received: from colin.muc.de ([193.149.48.1]:64274 helo=mail.muc.de) by eggs.gnu.org with smtp (Exim 4.90_1) (envelope-from ) id 1nCo4D-0007Vd-FN for emacs-devel@gnu.org; Wed, 26 Jan 2022 14:34:55 -0500 Original-Received: (qmail 26694 invoked by uid 3782); 26 Jan 2022 19:34:50 -0000 Original-Received: from acm.muc.de (p4fe156d4.dip0.t-ipconnect.de [79.225.86.212]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Wed, 26 Jan 2022 20:34:50 +0100 Original-Received: (qmail 32281 invoked by uid 1000); 26 Jan 2022 19:34:49 -0000 Content-Disposition: inline In-Reply-To: X-Submission-Agent: TMDA/1.3.x (Ph3nix) X-Primary-Address: acm@muc.de Received-SPF: pass client-ip=193.149.48.1; envelope-from=acm@muc.de; helo=mail.muc.de 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=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 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:285453 Archived-At: Hello, Gregory. On Wed, Jan 26, 2022 at 18:41:57 +0000, Gregory Heytings wrote: > > I think we need more measurements in scenarios closer to actual Emacs > > usage. One is intensive display operation -- I think Alan posted > > something to that effect. Another could be starting Gnus to read a > > large newsgroup. Yet another could be reindent a large piece of C or > > Python or Lisp code. Perhaps also "M-x occur" through a large buffer. > > Stuff like that -- any command that tends to be used frequently and is > > known to take a tangible amount of time. > The problem is that, IME, such benchmarks do not show anything when the > slowdown is not significant enough (> 10%), because the measurements vary > a lot depending on external factors. I wonder how Alan could conclude > that there is a slowdown of "less than 1%", when I run his benchmark on my > (otherwise unloaded) computer, the running times I get are anywhere > between 17s and 20s. Taking the average of such measures does not really > make sense. No, but the first run in an Emacs session tends to be shorter than subsequent runs. I don't know why. I take it you also saw a very small difference in the timings for this benchmark between the two versions. Otherwise you would have said, I think. The four measurements I got from my benchmark in master (from benchmark-run) were: o - (20.798601883 460 7.728701306) o - (20.947118356 295 7.1172684969999995) o - (20.941589929 293 7.144901186) o - (20.917180235 293 7.136285445000002) The corresponding four from the (then) branch were o - (20.854543266 480 7.691123986) o - (21.064465459 320 7.189660959000001) o - (21.143813105 318 7.287708998000001) o - (21.115932422 318 7.266432223999999) It is fairly clear the second set are ~1% more than the first set, give or take unimportant measurement errors. That's precisely what I meant when I said that the branch was about 1% slower ON THAT BENCHMARK. Please note what I said, going back to my original post if needed. I did not say "less than" 1%. I was not referring to the speed in general. I was very specific about what I wrote. > However, I found one measurement that seems to give reasonably stable > results. On my Debian bookworm computer, with a standard build, on > src/xdisp.c, (benchmark-run 100 (occur "a.b")) needs on average (with 10 > runs) 7.42 seconds (standard deviation 0.04) on 3b33a14380 and 7.66 > seconds (standard deviation 0.05) on 7922131bb2. That's a >3% slowdown. Yes, that's around 3.2%. Scarcely something you'd notice in an interactive session, where the difference is around the time it takes to depress a key on the keyboard. So we now have a real life measurement which is more than 1%. It's nowhere near 10%, though. -- Alan Mackenzie (Nuremberg, Germany).