From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Some experience with the igc branch Date: Tue, 24 Dec 2024 16:40:04 +0200 Message-ID: <861pxx2lh7.fsf@gnu.org> References: <87o713wwsi.fsf@telefonica.net> <87ldw7fwet.fsf@protonmail.com> <87a5cnfj8t.fsf@protonmail.com> <86seqe4j4f.fsf@gnu.org> <87ttaucub8.fsf@protonmail.com> <87pllicrpi.fsf@protonmail.com> <864j2u442i.fsf@gnu.org> <87ldw6as5f.fsf@protonmail.com> <86o7112rnq.fsf@gnu.org> <867c7p2nz4.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="26922"; mail-complaints-to="usenet@ciao.gmane.io" Cc: pipcet@protonmail.com, ofv@wanadoo.es, emacs-devel@gnu.org, eller.helmut@gmail.com, acorallo@gnu.org To: Gerd =?utf-8?Q?M=C3=B6llmann?= Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Tue Dec 24 15:40:53 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 1tQ65d-0006rk-3r for ged-emacs-devel@m.gmane-mx.org; Tue, 24 Dec 2024 15:40:53 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tQ64y-0005sb-Ud; Tue, 24 Dec 2024 09:40:13 -0500 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 1tQ64u-0005pR-3M for emacs-devel@gnu.org; Tue, 24 Dec 2024 09:40:09 -0500 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tQ64t-0008EP-2C; Tue, 24 Dec 2024 09:40:07 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=MIME-version:References:Subject:In-Reply-To:To:From: Date; bh=2hl7oJCvsyvHvGy6/nRc0UH8sxmijWW1fWpvNcSnZ+c=; b=PoMn6gXXemfCTxbjV90v uT7SB7NFUc5IkLIM+nK5mCD/ubiNb1KD4VmIRh5tW92ehXv1rWMC55HVVNZvcGYRzq2Gxn4MkL5LW BXLqei2FVdxlzQnJbdcfOFMxbbkrVBqEzqwuhHsBtRgp826iZXWm2qgysoQ3e1S44klQkfYYl7v0j E83D/w44YvDw6I1dsga1A9u8ioHrZmrmRa3zvdWl9UVDgVQiuowieWsUXy6SBm5knkRw/9H0wa1eA HAYwDVLutwOf6d6sPdqXCyvOJzEVTq4wLp9Voc7Y90wzF06kUcpAY6L/DuV691kYNdFGIH2YfIGq1 cXykHCPElG+dzQ==; In-Reply-To: (message from Gerd =?utf-8?Q?M?= =?utf-8?Q?=C3=B6llmann?= on Tue, 24 Dec 2024 15:12:40 +0100) 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:327018 Archived-At: > From: Gerd Möllmann > Cc: pipcet@protonmail.com, ofv@wanadoo.es, emacs-devel@gnu.org, > eller.helmut@gmail.com, acorallo@gnu.org > Date: Tue, 24 Dec 2024 15:12:40 +0100 > > Eli Zaretskii writes: > > > Now, with that definition, isn't specpdl stack part of "Lisp data"? > > If so, and if we can safely access it from a signal handler, why do we > > need to move it aside at all? And how would the "message handler" be > > different in that aspect from a signal hanlder? > > We're coming from the problem that MPS uses signals for memory barriers. > On platforms != macOS. And I am proposing a solution for that. > > The SIGPROF handler does two things: (1) get the current backtrace, > which does not trip on memory barriers, and (2) build a summary, i.e. > count same backtraces using a hash table. (2) trips on memory barriers. Can you elaborate on (2) and why it trips? I guess I'm missing something because I don't understand which code in record_backtrace does trip on memory barriers and why.