From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#37321: 27.0.50; Excessive gc in a use case (el-search) Date: Tue, 08 Oct 2019 15:11:23 +0300 Message-ID: <83d0f7xwr8.fsf@gnu.org> References: <87lfv1pm5x.fsf@web.de> <874l1mc01w.fsf@web.de> <87woeidd4g.fsf@web.de> <733d0142-51ee-55df-de0c-cca7c989b370@cs.ucla.edu> <875zlgu2y8.fsf@web.de> <6d670180-e2ee-030f-ef0e-ad0c5c7a8ef5@cs.ucla.edu> <87tv8zs2r9.fsf@web.de> <83tv8zl0es.fsf@gnu.org> <87sgo3typ1.fsf@web.de> <83o8yry56c.fsf@gnu.org> <87lftvzjmr.fsf@web.de> <83k19fy4p7.fsf@gnu.org> <87pnj7xzhe.fsf@web.de> Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="193070"; mail-complaints-to="usenet@blaine.gmane.org" Cc: eggert@cs.ucla.edu, 37321@debbugs.gnu.org To: Michael Heerdegen Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Tue Oct 08 14:12:15 2019 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iHoLd-000o44-V6 for geb-bug-gnu-emacs@m.gmane.org; Tue, 08 Oct 2019 14:12:14 +0200 Original-Received: from localhost ([::1]:54702 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iHoLc-0006mL-Mv for geb-bug-gnu-emacs@m.gmane.org; Tue, 08 Oct 2019 08:12:12 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:56204) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iHoLU-0006ki-Pc for bug-gnu-emacs@gnu.org; Tue, 08 Oct 2019 08:12:05 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iHoLT-0000E9-C4 for bug-gnu-emacs@gnu.org; Tue, 08 Oct 2019 08:12:04 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:40867) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1iHoLS-0000Dt-Ez for bug-gnu-emacs@gnu.org; Tue, 08 Oct 2019 08:12:03 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1iHoLS-0002OQ-7Y for bug-gnu-emacs@gnu.org; Tue, 08 Oct 2019 08:12:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Tue, 08 Oct 2019 12:12:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 37321 X-GNU-PR-Package: emacs Original-Received: via spool by 37321-submit@debbugs.gnu.org id=B37321.15705367039172 (code B ref 37321); Tue, 08 Oct 2019 12:12:02 +0000 Original-Received: (at 37321) by debbugs.gnu.org; 8 Oct 2019 12:11:43 +0000 Original-Received: from localhost ([127.0.0.1]:49688 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iHoL5-0002Nn-6d for submit@debbugs.gnu.org; Tue, 08 Oct 2019 08:11:43 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:47084) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1iHoL2-0002NZ-R5 for 37321@debbugs.gnu.org; Tue, 08 Oct 2019 08:11:37 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:41115) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1iHoKx-0008K3-3T; Tue, 08 Oct 2019 08:11:31 -0400 Original-Received: from [176.228.60.248] (port=3397 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1iHoKw-0007Vi-0N; Tue, 08 Oct 2019 08:11:30 -0400 In-reply-to: <87pnj7xzhe.fsf@web.de> (message from Michael Heerdegen on Tue, 08 Oct 2019 13:12:29 +0200) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.51.188.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.org gmane.emacs.bugs:168640 Archived-At: > From: Michael Heerdegen > Cc: eggert@cs.ucla.edu, 37321@debbugs.gnu.org > Date: Tue, 08 Oct 2019 13:12:29 +0200 > > Eli Zaretskii writes: > > > Start with 4 times the default. If that's not enough, double the > > value until you are satisfied, and tell what was the final value. > > I leave it to you to interpret the result (can we expect that other use > cases have a similar optimum?): > [...] > 61.893515s (14.088496s in 63 GCs) > > > (setq gc-cons-threshold (* 800000 128)) > > 56.277259s (8.122554s in 32 GCs) > > (setq gc-cons-threshold (* 800000 256)) > > 55.173263s (6.067774s in 17 GCs) > > (setq gc-cons-threshold (* 800000 512)) > > 56.116736s (8.825274s in 9 GCs) > > (setq gc-cons-threshold (* 800000 1024)) > > 70.832969s (19.474471s in 5 GCs) IMO, this suggests that your code produces a lot of garbage, so it is not a good basis for setting the default values. I would be OK with bumping up the default gc-cons-threshold 8-fold, or even 16-fold, but increasing it by a factor of 256 is too much, IMO: it would mean we only GC after consing ~200MB of data, which is about half the heap size of my current Emacs session, which has been up and running for 28 days, and has 360 live buffers. Thanks.