From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 31719 invoked by alias); 11 Dec 2009 16:35:26 -0000 Received: (qmail 31710 invoked by uid 22791); 11 Dec 2009 16:35:25 -0000 X-SWARE-Spam-Status: No, hits=-1.9 required=5.0 tests=AWL,BAYES_00,SARE_MSGID_LONG40,SPF_PASS X-Spam-Check-By: sourceware.org Received: from mail-ew0-f223.google.com (HELO mail-ew0-f223.google.com) (209.85.219.223) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Fri, 11 Dec 2009 16:35:18 +0000 Received: by ewy23 with SMTP id 23so1262557ewy.4 for ; Fri, 11 Dec 2009 08:35:15 -0800 (PST) MIME-Version: 1.0 Received: by 10.213.96.195 with SMTP id i3mr1702291ebn.97.1260549314990; Fri, 11 Dec 2009 08:35:14 -0800 (PST) In-Reply-To: <008401ca7a3a$272f65f0$758e31d0$@com> References: <816087.35180.qm@web112515.mail.gq1.yahoo.com> <4B218B30.4010501@vmware.com> <119734.20965.qm@web112506.mail.gq1.yahoo.com> <4B21B85F.1030502@vmware.com> <5e81cb500912101948nb8b09e8j7d58f6332ec62a38@mail.gmail.com> <008401ca7a3a$272f65f0$758e31d0$@com> Date: Fri, 11 Dec 2009 16:35:00 -0000 Message-ID: <5e81cb500912110835o3c26e0d8u605b84161a2b6100@mail.gmail.com> Subject: Re: porting reversible on arm/mips From: Sean Chen To: Jakob Engblom Cc: Michael Snyder , paawan oza , Hui Zhu , gdb@sourceware.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-IsSubscribed: yes 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 X-SW-Source: 2009-12/txt/msg00073.txt.bz2 On Fri, Dec 11, 2009 at 4:15 PM, Jakob Engblom wrote: >> I was interested in the porting on ARM. But later I found that the >> performance impact on ARM might damage the usage of process record. In >> my experiment, reversible debugging is about 20000x slower, which >> might be endurable on the modern computer. However, ARM target is tens >> of times (or even more if we consider the memory) slower than PC. So >> recording instructions will be very slow, about thousands of >> instructions per second. > > I just must pitch in and say that it depends on the simulator. > > An advantage to using a full simulator is that you simplify the system an= d no > longer have to care about OS calls: the OS is just part of the context yo= u save > and reverse. =A0So the overhead actually goes down compared to native pre= c. =A0I > think a reversible ARM simulator can be made to run within a factor of te= n of > native speed, easily. > > > Best regards, > > /jakob > > _______________________________________________________ > > Jakob Engblom, PhD, Technical Marketing Manager > > Virtutech=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 Direct: += 46 8 690 07 47 > Drottningholmsv=E4gen 22=A0=A0=A0=A0=A0 Mobile: +46 709 242 646 > 11243 Stockholm=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 Web:=A0=A0=A0 www.vir= tutech.com > Sweden > ________________________________________________________ > > > > > > The performance of reversible debugging with simulator build-in support should not be so low. But if Oza means reversible debugging with process record, performance will be the truth we have to face. --=20 Best Regards, Sean Chen