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: Pure space Date: Fri, 16 Aug 2024 19:07:42 +0000 Message-ID: <87cym8jngk.fsf@protonmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="19427"; mail-complaints-to="usenet@ciao.gmane.io" To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Aug 17 07:42:14 2024 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 1sfCCc-0004sI-Es for ged-emacs-devel@m.gmane-mx.org; Sat, 17 Aug 2024 07:42:14 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sfCC5-0005iX-6p; Sat, 17 Aug 2024 01:41:41 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sf2If-0003sa-V2 for emacs-devel@gnu.org; Fri, 16 Aug 2024 15:07:49 -0400 Original-Received: from mail-40134.protonmail.ch ([185.70.40.134]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sf2Id-0007BN-Oi for emacs-devel@gnu.org; Fri, 16 Aug 2024 15:07:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=protonmail3; t=1723835265; x=1724094465; bh=dllmL8TnHTA3YdZSOzyhDCZGIhc5b/jJdePtCOo1NqY=; h=Date:To:From:Subject:Message-ID:Feedback-ID:From:To:Cc:Date: Subject:Reply-To:Feedback-ID:Message-ID:BIMI-Selector; b=ZTmNzi7pk72cmWczNx/WLhGj42+hcF9OZMIhlsKMw2H1CKTD/yqrP6uGMa8mpUDCM gNCUNzLDXPtf+DNoupOhc9BaLXkfLvPPkzQ143l+jag/99eWwmAgJfNv9g6vISHywn C7dEhBRqlE89XClFa4jUn9C+FhTJLIgHcO/xowqLX+NNfH/80p6B1rna6L7JRZhDLy 54OH0iIbfD1e1DXKulRqAHzwZgvhiRS/IdtDpe8wFaLkpTHJlzLMHZJtL5H9n1BY8C vrO13Ki48P+70jF61RPgaylhr4Ys/eBtTx1NYfoUvGCKVNSeIc1KKqGdjZO2CE/oEx 2mvA8kNfdPM3g== Feedback-ID: 112775352:user:proton X-Pm-Message-ID: 6255917134fa1b8df2cee081e27d8ae6e9d49b18 Received-SPF: pass client-ip=185.70.40.134; envelope-from=pipcet@protonmail.com; helo=mail-40134.protonmail.ch 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_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-Mailman-Approved-At: Sat, 17 Aug 2024 01:41:33 -0400 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-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:322820 Archived-At: Hello everyone, can we revisit the question of whether we still want pure space? I just tracked down another pure space related bug, and I believe there's ample evidence now that it's slowing down not just me but other developers: * Gerd no longer uses purespace. He's added support for purespace to the MPS branch, but I imagine this took a while. * Danny's recent regexp patch included some code for pure space, which I believe was unnecessary effort * Adding headers to pure space objects in the MPS branch required some effort I believe everyone who knows the source code can agree that pure space adds significant complexity to the code, and I'm afraid that fixing the remaining bugs (such as 'valid_lisp_object_p' returning 1 for all objects that happen to point anywhere into pure space) would make it even more complex. I think it's particularly problematic to attempt to survive pure space overflow: that means there are now "pure" objects for which PURE_P returns false, and that's what caused this latest bug. I keep running into pure space overflows that I think are caused by going back and forth between configurations with and without native compilation (without doing a full make bootstrap, which fixes things). I'm willing to accept that's my fault, but I shouldn't have to track down segfaults caused by that. So, even if the decision is to keep pure space, can we at least make pure space overflow a fatal condition? I'd like some indication of how people see this before reopening scratch/no-purespace... Thanks Pip