From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20321 invoked by alias); 21 Jan 2008 17:19:56 -0000 Received: (qmail 20313 invoked by uid 22791); 21 Jan 2008 17:19:55 -0000 X-Spam-Check-By: sourceware.org Received: from py-out-1112.google.com (HELO py-out-1112.google.com) (64.233.166.176) by sourceware.org (qpsmtpd/0.31) with ESMTP; Mon, 21 Jan 2008 17:19:38 +0000 Received: by py-out-1112.google.com with SMTP id f31so2647134pyh.18 for ; Mon, 21 Jan 2008 09:19:35 -0800 (PST) Received: by 10.35.62.19 with SMTP id p19mr8181048pyk.4.1200935975654; Mon, 21 Jan 2008 09:19:35 -0800 (PST) Received: by 10.35.36.15 with HTTP; Mon, 21 Jan 2008 09:19:35 -0800 (PST) Message-ID: <8f2776cb0801210919v7ae9a72q657c4c7b4232ac2b@mail.gmail.com> Date: Mon, 21 Jan 2008 17:19:00 -0000 From: "Jim Blandy" To: "Mark Kettenis" Subject: Re: [RFA] Ignore breakpoints when reading memory. Cc: vladimir@codesourcery.com, gdb-patches@sources.redhat.com In-Reply-To: <200712041811.lB4IBToM005652@brahms.sibelius.xs4all.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200712011419.45773.vladimir@codesourcery.com> <200712041811.lB4IBToM005652@brahms.sibelius.xs4all.nl> X-Google-Sender-Auth: cca7491a74b90fe6 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: 2008-01/txt/msg00507.txt.bz2 On Dec 4, 2007 10:11 AM, Mark Kettenis wrote: > > From: Vladimir Prus > > Date: Sat, 1 Dec 2007 14:19:45 +0300 > > > > This commit prepares us for always-inserted-breakpoints mode. > > If breakpoints are always inserted, then reading the code memory > > will read the breakpoint instructions, not the original content. > > This patch makes us try to restore the original comments using > > the breakpoints table. OK? > > So now reading from target memory will need to traverse the complete > list of inserted breakpoints. Did you do any benchmarking to see what > the impact of this change is, especially when running on a somewhat > slow machine? I measured this on my laptop (not slow), by timing 'runtest break.exp call-ar-st.exp' nine times. I got: with patch: user (+ 1.57 1.55 1.51 1.58 1.64 1.59 1.68 1.54 1.53) 14.19 without patch: user (+ 1.55 1.61 1.54 1.52 1.58 1.60 1.55 1.58 1.61) 14.14 These times include the compilations, symbol table reading, and so on. It would have been better to write a custom expect script, and perhaps add a GDB maintenance command to print the current running total for CPU time. But for what it is, the effect of the patch is in the noise.