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: Timings for 'make check' with and without symbols with position Date: Sun, 27 Feb 2022 12:15:14 +0000 Message-ID: References: <83bkytpnyt.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="16511"; mail-complaints-to="usenet@ciao.gmane.io" Cc: ofv@wanadoo.es, deng@randomsample.de, mattiase@acm.org, emacs-devel@gnu.org, gregory@heytings.org, larsi@gnus.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sun Feb 27 13:17:25 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 1nOIUP-00046m-O0 for ged-emacs-devel@m.gmane-mx.org; Sun, 27 Feb 2022 13:17:25 +0100 Original-Received: from localhost ([::1]:55052 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nOIUO-0006T6-Il for ged-emacs-devel@m.gmane-mx.org; Sun, 27 Feb 2022 07:17:24 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:59486) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nOISb-0004vw-GQ for emacs-devel@gnu.org; Sun, 27 Feb 2022 07:15:33 -0500 Original-Received: from colin.muc.de ([193.149.48.1]:34137 helo=mail.muc.de) by eggs.gnu.org with smtp (Exim 4.90_1) (envelope-from ) id 1nOISZ-00044q-VI for emacs-devel@gnu.org; Sun, 27 Feb 2022 07:15:33 -0500 Original-Received: (qmail 99021 invoked by uid 3782); 27 Feb 2022 12:15:15 -0000 Original-Received: from acm.muc.de (p2e5d585e.dip0.t-ipconnect.de [46.93.88.94]) (using STARTTLS) by colin.muc.de (tmda-ofmipd) with ESMTP; Sun, 27 Feb 2022 13:15:14 +0100 Original-Received: (qmail 6092 invoked by uid 1000); 27 Feb 2022 12:15:14 -0000 Content-Disposition: inline In-Reply-To: <83bkytpnyt.fsf@gnu.org> 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, T_SCC_BODY_TEXT_LINE=-0.01 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:286718 Archived-At: Hello, Eli. On Sat, Feb 26, 2022 at 18:55:06 +0200, Eli Zaretskii wrote: > > Date: Sat, 26 Feb 2022 16:39:05 +0000 > > Cc: David Engster , Eli Zaretskii , > > larsi@gnus.org, mattiase@acm.org, gregory@heytings.org, > > Óscar Fuentes > > From: Alan Mackenzie > > > > Short summary: The new build is slower than the old by 12.6%. perf > > counted 419k samples on the new, 372k samples on the old. > > > > What is taking the extra time is largely the garbage collection: I > > filtered perf's output successively for the strings "mark" and "sweep", > > and include those functions with at least 0.1% of the run time. > Thanks. Any idea why there will be more GC in the new version? Char-tables seem to have something to do with it. The perf output for mark_char_table increase from 2.98% to 3.79%. Adding the 12.6% factor onto the 3.79% gives us 4.27%. That's a factor of ~1.5 increase. I'm still slogging through the detailed output for mark_char_table, which is not easy in the optimised build. I suspect that somehow, somewhere, symbols with position have got themselves into a char-table, and they take (a lot) longer to process than bare symbols (for which mark_char_table is optimised). I've not yet managed to find such a char-table though. > Or are you saying the number of GC calls was the same, but each GC > cycle took a bit longer? I've tried to get an output of gcs-done at the end of the batch emacs invocation in make check, but not yet managed it. Maybe later. > If so, how does symbols-with-pos affect GC? I don't yet have a hypothesis for this. -- Alan Mackenzie (Nuremberg, Germany).