From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: GC and stack marking Date: Wed, 21 May 2014 13:40:21 -0400 Message-ID: References: <83a9add91p.fsf@gnu.org> <8338g4bd7m.fsf@gnu.org> <83wqdgntan.fsf@gnu.org> <83ppj7oniv.fsf@gnu.org> <838upvnnsq.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1400694058 24319 80.91.229.3 (21 May 2014 17:40:58 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 21 May 2014 17:40:58 +0000 (UTC) Cc: fabrice.popineau@gmail.com, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed May 21 19:40:50 2014 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1WnAVW-0007Fq-IM for ged-emacs-devel@m.gmane.org; Wed, 21 May 2014 19:40:50 +0200 Original-Received: from localhost ([::1]:32926 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WnAVV-0000Dh-VG for ged-emacs-devel@m.gmane.org; Wed, 21 May 2014 13:40:49 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:43354) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WnAVL-0000DZ-Mp for emacs-devel@gnu.org; Wed, 21 May 2014 13:40:47 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WnAVD-0002yf-V8 for emacs-devel@gnu.org; Wed, 21 May 2014 13:40:39 -0400 Original-Received: from ironport2-out.teksavvy.com ([206.248.154.181]:8422) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WnAV4-0002x7-G3; Wed, 21 May 2014 13:40:22 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ArUGAIDvNVPO+KQe/2dsb2JhbABZgwaDSsA9gRcXdIIlAQEBAQIBViMFCws0EhQYDSSIBAjSGReOegeEOASpGYFqg0wh X-IPAS-Result: ArUGAIDvNVPO+KQe/2dsb2JhbABZgwaDSsA9gRcXdIIlAQEBAQIBViMFCws0EhQYDSSIBAjSGReOegeEOASpGYFqg0wh X-IronPort-AV: E=Sophos;i="4.97,753,1389762000"; d="scan'208";a="63546436" Original-Received: from 206-248-164-30.dsl.teksavvy.com (HELO pastel.home) ([206.248.164.30]) by ironport2-out.teksavvy.com with ESMTP/TLS/ADH-AES256-SHA; 21 May 2014 13:40:21 -0400 Original-Received: by pastel.home (Postfix, from userid 20848) id 99CED601F5; Wed, 21 May 2014 13:40:21 -0400 (EDT) In-Reply-To: <838upvnnsq.fsf@gnu.org> (Eli Zaretskii's message of "Wed, 21 May 2014 18:39:49 +0300") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4.50 (gnu/linux) 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: 2.1.14 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-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:172000 Archived-At: > I already tried that before, and came up empty-handed. I tried again > now; the address of that value on the stack does not correspond to any > local variable in the corresponding stack frame, and I also cannot > find that address in the disassembly of the function whose stack frame > includes the value. It might simply be a slot that's unused by the current stack frame, whose value comes from some stack frame that existed some time in the past. Which stack frame is that? Is it high up or very deep (both of which we could hope to solve by using tighter bounds on the start and end addresses of the stack scan), or neither? > Now, I have a question: mark_stack stops examining the stack when it > gets to its own stack frame. That is certainly safe, but it sounds > too conservative: it should stop at the stack frame of > Fgarbage_collect, I think, because no live Lisp object can appear > while Fgarbage_collect runs, right? Sounds right, yes. Stefan