From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 12564 invoked by alias); 25 Feb 2016 03:31:17 -0000 Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org Received: (qmail 11659 invoked by uid 89); 25 Feb 2016 03:29:55 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.0 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=ham version=3.3.2 spammy=Hx-languages-length:936, lucky, psymtab X-HELO: gproxy5-pub.mail.unifiedlayer.com Received: from gproxy5-pub.mail.unifiedlayer.com (HELO gproxy5-pub.mail.unifiedlayer.com) (67.222.38.55) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with SMTP; Thu, 25 Feb 2016 03:29:54 +0000 Received: (qmail 24484 invoked by uid 0); 25 Feb 2016 03:20:33 -0000 Received: from unknown (HELO cmgw2) (10.0.90.83) by gproxy5.mail.unifiedlayer.com with SMTP; 25 Feb 2016 03:20:33 -0000 Received: from box522.bluehost.com ([74.220.219.122]) by cmgw2 with id NTLR1s00X2f2jeq01TLUb7; Wed, 24 Feb 2016 20:20:31 -0700 X-Authority-Analysis: v=2.1 cv=PPOcp5aC c=1 sm=1 tr=0 a=GsOEXm/OWkKvwdLVJsfwcA==:117 a=GsOEXm/OWkKvwdLVJsfwcA==:17 a=L9H7d07YOLsA:10 a=9cW_t1CCXrUA:10 a=s5jvgZ67dGcA:10 a=PnD2wP_eR3oA:10 a=ezDAll7g0wUA:10 a=jFJIQSaiL_oA:10 a=hSOwerT2o--u5-1m-eoA:9 Received: from [71.218.200.158] (port=44498 helo=bapiya) by box522.bluehost.com with esmtpsa (TLSv1.2:AES128-GCM-SHA256:128) (Exim 4.84) (envelope-from ) id 1aYmTa-00032m-W0; Wed, 24 Feb 2016 20:20:27 -0700 From: Tom Tromey To: Jan Kratochvil Cc: Simon Marchi , Tom Tromey , Pedro Alves , gdb@sourceware.org Subject: Re: Multi-threaded dwarf parsing References: <2c38d5c574de28faa9fc94fe4ed17d45@simark.ca> <56CD8EC0.3010304@redhat.com> <87lh6a6s8s.fsf@tromey.com> <20160224202519.GA10251@host1.jankratochvil.net> Date: Thu, 25 Feb 2016 03:31:00 -0000 In-Reply-To: <20160224202519.GA10251@host1.jankratochvil.net> (Jan Kratochvil's message of "Wed, 24 Feb 2016 21:25:19 +0100") Message-ID: <871t81qxvs.fsf@tromey.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.0.91 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Identified-User: {36111:box522.bluehost.com:elynrobi:tromey.com} {sentby:smtp auth 71.218.200.158 authed with tom+tromey.com} X-SW-Source: 2016-02/txt/msg00031.txt.bz2 Jan> With .gdb_index GDB still has startup performance problems during Jan> full CU expansions, that is struct symtab and struct symbol. My branch "lazily-read-function-bodies" addressed this issue. It changed CU expansion to skip reading function bodies until needed. This was good for a decent speedup; my notes say ~40%. I didn't finish this branch, though -- it still needed a bit of work to expand a function when a by-address lookup was done. It's possible, but harder, to go even farther than this -- that is, unify symtabs and psymtabs and make CU expansion completely lazy. At one point I had a rather complicated plan for this. For what it's worth, in my current debugging, I do notice psymtab reading, but I never notice CU expansion. I'm not sure if I'm just lucky or if it's because the CU expansion problem is exacerbated by dwz, which I'm of course not using during development. Tom