From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.bugs Subject: bug#45200: Memory leaks: (garbage-collect) fails to reclaim memory Date: Sun, 24 Jan 2021 13:51:41 -0500 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="36539"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) Cc: 45200@debbugs.gnu.org To: Konstantin Kharlamov Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sun Jan 24 19:52:12 2021 Return-path: Envelope-to: geb-bug-gnu-emacs@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 1l3kUc-0009Lh-Ku for geb-bug-gnu-emacs@m.gmane-mx.org; Sun, 24 Jan 2021 19:52:10 +0100 Original-Received: from localhost ([::1]:49232 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l3kUa-0005os-VJ for geb-bug-gnu-emacs@m.gmane-mx.org; Sun, 24 Jan 2021 13:52:09 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:53164) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l3kUT-0005og-Un for bug-gnu-emacs@gnu.org; Sun, 24 Jan 2021 13:52:01 -0500 Original-Received: from debbugs.gnu.org ([209.51.188.43]:53947) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1l3kUT-0001gV-Mq for bug-gnu-emacs@gnu.org; Sun, 24 Jan 2021 13:52:01 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1l3kUT-0001kW-Kh for bug-gnu-emacs@gnu.org; Sun, 24 Jan 2021 13:52:01 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Stefan Monnier Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sun, 24 Jan 2021 18:52:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 45200 X-GNU-PR-Package: emacs Original-Received: via spool by 45200-submit@debbugs.gnu.org id=B45200.16115143186715 (code B ref 45200); Sun, 24 Jan 2021 18:52:01 +0000 Original-Received: (at 45200) by debbugs.gnu.org; 24 Jan 2021 18:51:58 +0000 Original-Received: from localhost ([127.0.0.1]:37260 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1l3kUP-0001kF-SL for submit@debbugs.gnu.org; Sun, 24 Jan 2021 13:51:58 -0500 Original-Received: from mailscanner.iro.umontreal.ca ([132.204.25.50]:34091) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1l3kUO-0001k0-5o for 45200@debbugs.gnu.org; Sun, 24 Jan 2021 13:51:56 -0500 Original-Received: from pmg2.iro.umontreal.ca (localhost.localdomain [127.0.0.1]) by pmg2.iro.umontreal.ca (Proxmox) with ESMTP id 7DB0D80B69; Sun, 24 Jan 2021 13:51:50 -0500 (EST) Original-Received: from mail01.iro.umontreal.ca (unknown [172.31.2.1]) by pmg2.iro.umontreal.ca (Proxmox) with ESMTP id EEDD280057; Sun, 24 Jan 2021 13:51:48 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=iro.umontreal.ca; s=mail; t=1611514309; bh=tiaED2ZbqzCrNjpdzBUTKfq/fzgmO6rpkQQf+lPUOSc=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=T65lOMKDRlIcdDVJPKfMx/IAgzUMYq9/iHIrmzfg6ye3UvaPrBBqsXn1O9L5i+pK4 1SxeoXJEcbv7EaomNTtToRcoR6jirgL5sAfu3RAubfB4qyPqsKce+cR3am1XvQh0IC zi5L8pW5CQpgHuKubTuNGuc9Wy1gPJEm1zEivJ5GGL1RQCB4HlOTJgmV/uYbQtAR3y +KCUde6jjtjGc94RchG8mipe2YiF9Km9QSDO/NF+oAmyG1orQs844xFoifu6B2FjTz WvGVnpvf4RNiZbPAN5pXgp7rgJeg4KMyMIhuiBcYt41T4j48txufh48x39p/W9sXjd EpMnJ7OeK4V9Q== Original-Received: from alfajor (69-196-141-46.dsl.teksavvy.com [69.196.141.46]) by mail01.iro.umontreal.ca (Postfix) with ESMTPSA id BA4801201CC; Sun, 24 Jan 2021 13:51:48 -0500 (EST) In-Reply-To: (Konstantin Kharlamov's message of "Sat, 12 Dec 2020 21:43:10 +0300") X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list 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-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:198511 Archived-At: > # Steps to reproduce: > > 1. Run `mkdir /tmp/.emacs.d` > 2. Run emacs as `HOME=/tmp/ emacs`, and measure its PSS > 3. Create a file /tmp/.emacs.d/early-init.el with content: > > ;; only run garbage collection on idle > (setq gc-cons-threshold most-positive-fixnum) > (run-with-idle-timer 2 t (lambda () (garbage-collect))) > > 4. Run emacs as `HOME=/tmp/ emacs`, evaluate (garbage-collect), then measure its PSS > > ## Expected > > Size has no statistically-significant difference, because in both > cases we garbage-collected memory. I disagree with this expectation: it is perfectly normal for the amount of memory allocated to the Emacs process to be left higher if you delay the GC. There are various reasons for that: - fragmentation, of course. Not much we can do about it short of using a moving collector. - the desire to keep memory around rather than return it to the OS, under the assumption that we'll need it again soon. And it's not considered as a memory leak as long as that memory has indeed been needed in the past and that future allocations can still make use of it. Eli wrote: > Thanks, but is it really a good idea to call malloc_trim each time we > free some chunk of memory? I think if we want to call `malloc_trim`, the obvious place would be to do it at the end of `garbage_collect`. Stefan