From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 5009 invoked by alias); 24 Jun 2009 16:26:09 -0000 Received: (qmail 4986 invoked by uid 22791); 24 Jun 2009 16:26:08 -0000 X-SWARE-Spam-Status: No, hits=-1.8 required=5.0 tests=AWL,BAYES_00,FB_WORD1_END_DOLLAR,SARE_MSGID_LONG40,SPF_PASS X-Spam-Check-By: sourceware.org Received: from smtp-out.google.com (HELO smtp-out.google.com) (216.239.45.13) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 24 Jun 2009 16:26:02 +0000 Received: from spaceape23.eur.corp.google.com (spaceape23.eur.corp.google.com [172.28.16.75]) by smtp-out.google.com with ESMTP id n5OGPxg8016331 for ; Wed, 24 Jun 2009 09:26:00 -0700 Received: from yxe36 (yxe36.prod.google.com [10.190.2.36]) by spaceape23.eur.corp.google.com with ESMTP id n5OGPuvC015382 for ; Wed, 24 Jun 2009 09:25:57 -0700 Received: by yxe36 with SMTP id 36so1361936yxe.13 for ; Wed, 24 Jun 2009 09:25:56 -0700 (PDT) MIME-Version: 1.0 Received: by 10.90.28.16 with SMTP id b16mr1178708agb.101.1245860756140; Wed, 24 Jun 2009 09:25:56 -0700 (PDT) In-Reply-To: <20090624154618.GA1825@caradoc.them.org> References: <200906151658.n5FGwrN6026829@d12av02.megacenter.de.ibm.com> <20090624154618.GA1825@caradoc.them.org> Date: Wed, 24 Jun 2009 16:26:00 -0000 Message-ID: Subject: Re: [10/15] Basic value access routines From: Doug Evans To: Tom Tromey , Ulrich Weigand , gdb-patches@sourceware.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-System-Of-Record: true X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2009-06/txt/msg00645.txt.bz2 On Wed, Jun 24, 2009 at 8:46 AM, Daniel Jacobowitz wrote: > On Wed, Jun 24, 2009 at 09:31:16AM -0600, Tom Tromey wrote: >> A related idea that occurred to me is that, with Jan's type GC, we >> could detach types from objfiles and "intern" them (something like >> bcache-for-types). =A0This would only be a win if there are many >> identical types distributed across objfiles, though. > > There's plenty of identical types within a single objfile. =A0Load GDB > with -readnow, and I find 66 copies of the typedef for "FILE", for > instance. As a data point, I compiled gdb with -g -O2 and again with -gdwarf-4 -O2. -rwxr-x--- 1 dje eng 16321609 Jun 24 08:52 gdb -rwxr-x--- 1 dje eng 13019406 Jun 24 08:50 gdb-dw4 Starting gdb with -readnow and then examining space usage: -g -O2: gdb$ ps l 24343 F UID PID PPID PRI NI VSZ RSS WCHAN STAT TTY TIME COMMAND 0 67641 24343 24342 20 0 117356 97764 - S+ pts/13 0:00 ../../= ../.. -gdwarf-4 -O2: gdb$ ps l 24349 F UID PID PPID PRI NI VSZ RSS WCHAN STAT TTY TIME COMMAND 0 67641 24349 16588 20 0 72088 53280 - S+ pts/13 0:00 ../../= ../.. Until my comdat types patch is vetted more, these numbers are to be taken with a grain of salt, but they are promising.