From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from alt-proxy28.mail.unifiedlayer.com (alt-proxy28.mail.unifiedlayer.com [74.220.216.123]) by sourceware.org (Postfix) with ESMTPS id 56A353853555 for ; Mon, 4 Jul 2022 18:30:24 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 56A353853555 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=tromey.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=tromey.com Received: from cmgw10.mail.unifiedlayer.com (unknown [10.0.90.125]) by progateway1.mail.pro1.eigbox.com (Postfix) with ESMTP id 7A42910040421 for ; Mon, 4 Jul 2022 18:30:22 +0000 (UTC) Received: from box5379.bluehost.com ([162.241.216.53]) by cmsmtp with ESMTP id 8QpxoB1tjNVEz8QpyolRx7; Mon, 04 Jul 2022 18:30:22 +0000 X-Authority-Reason: nr=8 X-Authority-Analysis: v=2.4 cv=I5+g+Psg c=1 sm=1 tr=0 ts=62c331be a=ApxJNpeYhEAb1aAlGBBbmA==:117 a=ApxJNpeYhEAb1aAlGBBbmA==:17 a=dLZJa+xiwSxG16/P+YVxDGlgEgI=:19 a=RgO8CyIxsXoA:10:nop_rcvd_month_year a=Qbun_eYptAEA:10:endurance_base64_authed_username_1 a=BN5iKjR5dSbmv2Ep3ycA:9 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tromey.com; s=default; h=Content-Type:MIME-Version:Message-ID:In-Reply-To:Date:References :Subject:Cc:To:From:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=TS9FNUZDC84spnMauTY6eOk1j+EWwq2B+U3QCwwLcec=; b=L6cUo1xbPKgiLykjDHJ4FFXSbA LLM75Bo8TCpbW/pMD6YvbAnFT1Mrf0sX+FYMnl6lHoTkhBU7Wofd/KodUYOrMHa0d12y4R2vlXpbO uQ2TfNpM6NDAv3nV0Xogs3XYg; Received: from 71-211-187-180.hlrn.qwest.net ([71.211.187.180]:35188 helo=prentzel) by box5379.bluehost.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1o8Qpx-003lAx-MY; Mon, 04 Jul 2022 12:30:21 -0600 From: Tom Tromey To: Tom de Vries Cc: gdb-patches@sourceware.org, Tom Tromey Subject: Re: [PATCH 5/5] [gdb/symtab] Fix data race on per_cu->lang References: <20220629152914.13149-1-tdevries@suse.de> <20220629152914.13149-5-tdevries@suse.de> X-Attribution: Tom Date: Mon, 04 Jul 2022 12:30:17 -0600 In-Reply-To: <20220629152914.13149-5-tdevries@suse.de> (Tom de Vries's message of "Wed, 29 Jun 2022 17:29:14 +0200") Message-ID: <877d4svih2.fsf@tromey.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - box5379.bluehost.com X-AntiAbuse: Original Domain - sourceware.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - tromey.com X-BWhitelist: no X-Source-IP: 71.211.187.180 X-Source-L: No X-Exim-ID: 1o8Qpx-003lAx-MY X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: 71-211-187-180.hlrn.qwest.net (prentzel) [71.211.187.180]:35188 X-Source-Auth: tom+tromey.com X-Email-Count: 2 X-Source-Cap: ZWx5bnJvYmk7ZWx5bnJvYmk7Ym94NTM3OS5ibHVlaG9zdC5jb20= X-Local-Domain: yes X-Spam-Status: No, score=-3023.2 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, JMQ_SPF_NEUTRAL, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 04 Jul 2022 18:30:25 -0000 >>>>> "Tom" == Tom de Vries writes: Tom> Both writes are called from the parallel for in dwarf2_build_psymtabs_hard, Tom> this one directly: Tom> ... Tom> #1 process_psymtab_comp_unit gdb/dwarf2/read.c:6812 (gdb+0x830912) Tom> #2 operator() gdb/dwarf2/read.c:7102 (gdb+0x831902) Tom> #3 operator() gdb/../gdbsupport/parallel-for.h:171 (gdb+0x8723a8) Tom> ... Tom> and this one when handling cross-CU refs: Tom> ... Tom> #1 cooked_indexer::ensure_cu_exists(cutu_reader*, dwarf2_per_objfile*, \ Tom> sect_offset, bool, bool) gdb/dwarf2/read.c:17973 (gdb+0x85c522) This method tries to ensure that a CU isn't processed twice, using the 'scanned' field. Do you know why this isn't working? Tom> Fix this by guarding the write with a lock. I would rather we avoid locks. Ideally the existing exclusion mechanism should be made to work, but if that fails, perhaps we can use another atomic. Tom