From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 32208 invoked by alias); 15 Apr 2002 01:48:59 -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 32159 invoked from network); 15 Apr 2002 01:48:57 -0000 Received: from unknown (HELO nevyn.them.org) (128.2.145.6) by sources.redhat.com with SMTP; 15 Apr 2002 01:48:57 -0000 Received: from drow by nevyn.them.org with local (Exim 3.35 #1 (Debian)) id 16wvcK-0006WZ-00 for ; Sun, 14 Apr 2002 21:49:16 -0400 Date: Sun, 14 Apr 2002 18:48:00 -0000 From: Daniel Jacobowitz To: gdb@sources.redhat.com Subject: Re: [rfc] Frame based register cache / frame->unwind Message-ID: <20020414214916.A25012@nevyn.them.org> Mail-Followup-To: gdb@sources.redhat.com References: <3CB9ED82.8050007@cygnus.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3CB9ED82.8050007@cygnus.com> User-Agent: Mutt/1.3.23i X-SW-Source: 2002-04/txt/msg00246.txt.bz2 On Sun, Apr 14, 2002 at 04:58:42PM -0400, Andrew Cagney wrote: > Hello, > > To pull together several apparently random threads. The attached is a > work in progress to add a frame based register cache to GDB. It appears > to work - NetBSD/PPC shows no regressions. > > Performance is hard to quantify(1) but looks positive. Using a native > GDB (not typical for me :-) it appears that each frame is ~2% slower to > create (``(gdb) up''). Once created, the frame is ~20-25% faster > (``(gdb) info registers''). You might want to try timing the testsuite with and without this patch (using /usr/bin/time et al., to get real/user/sys times) and see what changes. It'll probably be negligible, but you never know. > I'm not too worried about the apparent 2% overhead per frame create > though. With the patch applied, the code ends up maintaining both this > new cache and the old ->saved_regs table. Rewriting a target to just > use the ->unwind_cache, should, I think, claw back the 2% and then some > - less need to go out to the target. Completely agree. > > There are two parts to the change and I'll describe each in turn. The > final patch will likely be committed as two parts. Looks wonderful to me! -- Daniel Jacobowitz Carnegie Mellon University MontaVista Software Debian GNU/Linux Developer