From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: Overlays as an AA-tree Date: Wed, 08 Feb 2017 08:04:06 -0500 Message-ID: References: <87d1jylv43.fsf@fastmail.com> <87fujv64mn.fsf@hochschule-trier.de> <87fujvpkzc.fsf@fastmail.com> <87vasr5tqd.fsf@hochschule-trier.de> <87d1ex4kon.fsf@hochschule-trier.de> <87d1evod6x.fsf@fastmail.com> <877f53ftab.fsf@hochschule-trier.de> <878tpiqiuc.fsf@hochschule-trier.de> <87shnppspb.fsf@hochschule-trier.de> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1486559114 5855 195.159.176.226 (8 Feb 2017 13:05:14 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 8 Feb 2017 13:05:14 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.0.50 (gnu/linux) Cc: Joakim Jalap , emacs-devel@gnu.org To: Andreas Politz Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Feb 08 14:05:06 2017 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cbRvl-00018b-Oi for ged-emacs-devel@m.gmane.org; Wed, 08 Feb 2017 14:05:05 +0100 Original-Received: from localhost ([::1]:59394 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cbRvr-00043M-BS for ged-emacs-devel@m.gmane.org; Wed, 08 Feb 2017 08:05:11 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:54446) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cbRuv-00041v-9A for emacs-devel@gnu.org; Wed, 08 Feb 2017 08:04:14 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cbRus-0007vX-7L for emacs-devel@gnu.org; Wed, 08 Feb 2017 08:04:13 -0500 Original-Received: from ironport2-out.teksavvy.com ([206.248.154.181]:8927) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cbRus-0007vR-1u for emacs-devel@gnu.org; Wed, 08 Feb 2017 08:04:10 -0500 Original-Received: from 45-72-235-254.cpe.teksavvy.com (HELO pastel.home) ([45.72.235.254]) by smtp.teksavvy.com with ESMTP; 08 Feb 2017 08:04:08 -0500 Original-Received: by pastel.home (Postfix, from userid 20848) id DEDDF657DA; Wed, 8 Feb 2017 08:04:06 -0500 (EST) In-Reply-To: <87shnppspb.fsf@hochschule-trier.de> (Andreas Politz's message of "Tue, 07 Feb 2017 23:00:16 +0100") X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 206.248.154.181 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 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.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:212131 Archived-At: > I have a question: The comment in lisp.h says not make Lisp_Misc bigger. All Lisp_Misc use the same space. This Lisp_Misc thingy was introduced because the overhead of using a Lisp_Vectorlike was a bit higher than we liked for those smallish objects (in terms of memory use as well as in terms of CPU time needed for allocation/deallocation). So, if you need an object to be larger, just take it out of Lisp_Misc and use a Lisp_Vectorlike for it instead. The implementation of Lisp_Vectorlike has been significantly improved in the mean time, so the difference is not that large any more (but Lisp_Misc should still be faster to allocate and suffers much less from fragmentation). Stefan