From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 4312 invoked by alias); 13 Jun 2003 16:34:55 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 4257 invoked from network); 13 Jun 2003 16:34:54 -0000 Received: from unknown (HELO crack.them.org) (146.82.138.56) by sources.redhat.com with SMTP; 13 Jun 2003 16:34:54 -0000 Received: from dsl093-172-017.pit1.dsl.speakeasy.net ([66.93.172.17] helo=nevyn.them.org ident=mail) by crack.them.org with asmtp (Exim 3.12 #1 (Debian)) id 19QrWc-0002HH-00; Fri, 13 Jun 2003 11:35:38 -0500 Received: from drow by nevyn.them.org with local (Exim 3.36 #1 (Debian)) id 19QrVk-0003g0-00; Fri, 13 Jun 2003 12:34:44 -0400 Date: Fri, 13 Jun 2003 16:34:00 -0000 From: Daniel Jacobowitz To: Andrew Cagney Cc: Elena Zannoni , David Carlton , gdb , Jim Blandy Subject: Re: DW_AT_specification and partial symtabs Message-ID: <20030613163444.GA14030@nevyn.them.org> Mail-Followup-To: Andrew Cagney , Elena Zannoni , David Carlton , gdb , Jim Blandy References: <20030612170545.GA16995@nevyn.them.org> <16104.47067.182016.78574@localhost.redhat.com> <20030613133414.GB29641@nevyn.them.org> <16105.55964.91811.625007@localhost.redhat.com> <3EE9EFFE.6050607@redhat.com> <20030613154932.GA313@nevyn.them.org> <3EE9FA99.8070201@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3EE9FA99.8070201@redhat.com> User-Agent: Mutt/1.5.1i X-SW-Source: 2003-06/txt/msg00257.txt.bz2 On Fri, Jun 13, 2003 at 12:23:53PM -0400, Andrew Cagney wrote: > >On Fri, Jun 13, 2003 at 11:38:38AM -0400, Andrew Cagney wrote: > > > >>Daniel wrote: > >> > >> > > > >>> > 1) is very easy to measure. GDB has a command line option --readnow > >>> > which forces symtabs to be read in immediately. I tried my normal > >>> > performance testcase: a dummy main() linked to all of mozilla's > >>> > component libraries, with full stabs debug info. Note stabs, not > >>> > DWARF2, so the timing may vary. Also note that we duplicate psymtab > >>> > and symtab creation doing it this way, so it overestimates the cost. > > > >> > >>I think that's an understatement. > > > > > >Not really. You can subtract the psymtab time from the combined time, > >and then compare. It still more than triples the time. > > So we agree, 25% is significant but 3% is not. > > A better question is what % of symtabs get draged in by a C++ `break > main; run'. Wasn't the original conjecture that symtabs get sucked in > anyway so why do it twice. I am pretty sure that the conjecture is false. I've fixed several things in this area. I run GDB on target boards, over NFS root, with limited RAM, and full debug info for libc and libstdc++. When I mess up lazy loading, I _notice_. At least I'm not working on the 3MHz FPGA right now. -- Daniel Jacobowitz MontaVista Software Debian GNU/Linux Developer