From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Ihor Radchenko Newsgroups: gmane.emacs.devel Subject: MPS: dangling markers Date: Thu, 27 Jun 2024 21:01:32 +0000 Message-ID: <87v81u85hv.fsf@localhost> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="40231"; mail-complaints-to="usenet@ciao.gmane.io" Cc: Gerd =?utf-8?Q?M=C3=B6llmann?= , Eli Zaretskii , eller.helmut@gmail.com, Stefan Monnier To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Thu Jun 27 23:01:11 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 1sMwEx-000ADB-Dx for ged-emacs-devel@m.gmane-mx.org; Thu, 27 Jun 2024 23:01:11 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sMwE6-00082c-Tg; Thu, 27 Jun 2024 17:00:19 -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 1sMwE4-0007xH-JW for emacs-devel@gnu.org; Thu, 27 Jun 2024 17:00:16 -0400 Original-Received: from mout01.posteo.de ([185.67.36.65]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sMwE0-00081Z-AY for emacs-devel@gnu.org; Thu, 27 Jun 2024 17:00:15 -0400 Original-Received: from submission (posteo.de [185.67.36.169]) by mout01.posteo.de (Postfix) with ESMTPS id 85B83240027 for ; Thu, 27 Jun 2024 23:00:09 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.net; s=2017; t=1719522009; bh=MK3C03m/ujOT6CPDn45TBFPHEsO/r8NHeKt/cYyh7kU=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type: From; b=hL0i/Iv0hCjU6KOZUAKJ5SlsMkm4QYZXPe2l2z3hG+r97b7wYQL4PPZ4cGrfRhG3j CMQupRW0NxugRiYJds8gCbrB4hopbcGkzFaVsCmt4ZYxBKgpeajX6ICWjQIjhydvYS 2HIFSPYzheBDC45z2MXS9bA6uZKeTsUJ4DlIo6biM5fqsAvuSxVxq5TtodKk+2zfdk 5Xi+z0IhJ7ug/nnY6V/KdjOD4ffTx1QHXHfcQ349q8AFn7gUcM93a5AcFKWcY0EXm6 8ZA1VqU9Qi/kh0vAljnx7slI1Kv6XO4zkDMccqaua6FIwvs+KvUGImkZKKWkAemCbu fAYTgGsgyG0xg== Original-Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4W99tw5k5tz6tyB; Thu, 27 Jun 2024 23:00:08 +0200 (CEST) Received-SPF: pass client-ip=185.67.36.65; envelope-from=yantar92@posteo.net; helo=mout01.posteo.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 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, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action 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:320783 Archived-At: Related: bug#71644, bug#63040 When running the scratch/igc branch, I noticed a severe slowdown (10x or more) of redisplay on my large Org buffers. - The redisplay manifests itself as I build agenda multiple times (agenda creates many new markers). - perf points to (1) itree lookup; (2) bytepos<->charpos, which implies that things may be related to the number of allocated markers and overlays. - I observe things slowing down as the number of "PVEC_MARKER" in the output of `igc-info' grows. - Forcing (igc--collect) returns speed to normal I believe that my observation reveals one important point that may need to be considered when using MPS: We may need to more careful about cases in Emacs C code that traverse object lists that may contain unreferenced objects. Because MPS does not perform GC as regularly as the traditional mark-and-sweep, some unreferenced objects may remain live and present in internal data structures for a long time. AFAIK, at least overlays, buffers, and markers are used in C code within object lists/trees are often traversed in full. If objects in these lists are not regularly garbage-collected, we may end up in situation when dead objects significantly impact performance. I believe that what I observe locally is exactly the described scenario. -- Ihor Radchenko // yantar92, Org mode contributor, Learn more about Org mode at . Support Org development at , or support my work at