From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Pip Cet Newsgroups: gmane.emacs.devel Subject: Re: Removing pure space Date: Thu, 4 Mar 2021 14:55:53 +0000 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="20376"; mail-complaints-to="usenet@ciao.gmane.io" Cc: emacs-devel@gnu.org To: Stefan Monnier Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Thu Mar 04 16:13:28 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 1lHpfM-0005BV-D5 for ged-emacs-devel@m.gmane-mx.org; Thu, 04 Mar 2021 16:13:28 +0100 Original-Received: from localhost ([::1]:41644 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lHpfL-0005Nl-DJ for ged-emacs-devel@m.gmane-mx.org; Thu, 04 Mar 2021 10:13:27 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:34060) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lHpOy-0001sr-Fh for emacs-devel@gnu.org; Thu, 04 Mar 2021 09:56:32 -0500 Original-Received: from mail-ot1-x32a.google.com ([2607:f8b0:4864:20::32a]:44280) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lHpOw-0002uP-UN for emacs-devel@gnu.org; Thu, 04 Mar 2021 09:56:32 -0500 Original-Received: by mail-ot1-x32a.google.com with SMTP id f33so27438881otf.11 for ; Thu, 04 Mar 2021 06:56:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=4cfKk6m/+C/W8jXseOrubU98HwyZoMbHkeLujG9woI8=; b=lXnJ14DgWycCZsvSwm8UtGBm7d5x1QrSKxal1oh0Bk5tCtjV8jlB0USsXLok5NZtdP dL5eqQ67UZHF+xSwtAf/wfEU6O36WHHUgDxVEu1rc03xzjAbNftTN0n6S67sxVcXydUz dgAIERLn34zbjjYUgHk2joGE+slYwcVsa7P+NAQY6YIwMRSiqtmKBsXOKYdKRakWUp/F nRsmG4k8EBOwXoHfUXQf+w4/DXKB51d6D28H7pMYZ+kK22GRuqABENlNpWSl0+CE3OTB YdxSLOsfB3wLkEOWPRnQDwrd3/g+D5BowgN7ydCSEL1wEsZAdmidr0YwXRhA60B5Et7m wBGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=4cfKk6m/+C/W8jXseOrubU98HwyZoMbHkeLujG9woI8=; b=Vt58fj8Oh26cQPj5r+lJsvwd29qVMFKAT7PuOyy0Wl6lTrt+9fLiug91G6XXx8QI4n D1F/7K2wb/58HgnJNywK7VWbEr/oFMKgNqfAGwJv07F1IOFumy9Hx8RjmsVg2gKOgcqp ostNRPeI62rzbNE1KdhkhIw50wvLYHe0apMQTUpAXHMx/vzzBVbl0GT4L1U1M0ESPZ/U FzbGP/vgMH8MFkXhHJ7QqhTUDWUDzYAUnUNGvH/ZK/4dx486nO9BBmTUeDCxWq3QurfL 6WpactvDezpxY6ZMvh7QFYWrswXI3DVTpi7l+5cuRw7qZA9YBEsJ7UiPuBeyC1V1JQen v+Ww== X-Gm-Message-State: AOAM530f793uDigXcTt8xReNjKA2e5pm3hFqt8OFTN37U2os0kS1IU1d lA0Ln7nULloLP/qiY3KGcBIqLSBxika6I/giZ0ssZQjNYuI= X-Google-Smtp-Source: ABdhPJwixS2m/ehptyBLI4JlW+nLHabDFQg2loRPZVHrnw+y20F2Pxv7zwXVkHKTkUJc2NEGJfU5oFC9v91lfEKGHJ0= X-Received: by 2002:a05:6830:11d4:: with SMTP id v20mr3659689otq.287.1614869789669; Thu, 04 Mar 2021 06:56:29 -0800 (PST) In-Reply-To: Received-SPF: pass client-ip=2607:f8b0:4864:20::32a; envelope-from=pipcet@gmail.com; helo=mail-ot1-x32a.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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:265963 Archived-At: On Thu, Mar 4, 2021 at 2:49 PM Stefan Monnier wrote: > > I have not been able to measure any performance changes with this > > patch applied, but unfortunately I'm currently on a system unsuitable > > for running reliable benchmarks. If this is a concern, any help > > measuring the performance impact more accurately would be appreciated. > > The main expected benefit from the purespace is that the GC doesn't need > to look at it, so the GC should be faster because it looks at a smaller > part of the heap. With pdumper, I don't think that's true anymore. There are three Lisp objects for which PURE_P returns true: the empty vector, unibyte string, and multibyte string. In fact, if anything, it'll be slower because of the extra overhead of the PURE_P checks... > So I think a good micro-benchmark which should expose the worst-case > impact of removing the purespace would be to compare the time taken to > perform GC (I think the effect should be most visible right at startup > since the more packages and stuff you have loaded, the smaller the > proportion of the heap kept in purespace). So you're saying I should build with unexec, then run something like: "time ./emacs --batch --eval '(dotimes (i 10000) (garbage-collect))' ? Because I don't really think that benchmark makes sense with pdumper... Pip