From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 4582 invoked by alias); 15 Dec 2009 02:40:56 -0000 Received: (qmail 4557 invoked by uid 22791); 15 Dec 2009 02:40:54 -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-f209.google.com (HELO mail-ew0-f209.google.com) (209.85.219.209) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 15 Dec 2009 02:40:45 +0000 Received: by ewy1 with SMTP id 1so4440266ewy.8 for ; Mon, 14 Dec 2009 18:40:42 -0800 (PST) MIME-Version: 1.0 Received: by 10.213.2.82 with SMTP id 18mr6521616ebi.58.1260844842379; Mon, 14 Dec 2009 18:40:42 -0800 (PST) In-Reply-To: References: <5e81cb500912040734u5ce67afdpd6a2d0e63173f908@mail.gmail.com> <5e81cb500912140518r2ad3f2fdrd0dd5a546e6d8a33@mail.gmail.com> Date: Tue, 15 Dec 2009 02:40:00 -0000 Message-ID: <5e81cb500912141840s389859c2r9c56dd8800adb731@mail.gmail.com> Subject: Re: UndoDB's performance From: Sean Chen To: Hui Zhu Cc: gdb@sourceware.org Content-Type: text/plain; charset=windows-1252 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/msg00090.txt.bz2 On Mon, Dec 14, 2009 at 11:07 PM, Hui Zhu wrote: > Try undodb. > > On Mon, Dec 14, 2009 at 21:18, Sean Chen wrote: >> On Mon, Dec 14, 2009 at 7:14 PM, Hui Zhu wrote: >>> gdb-7 reverse debugging accelerator. >>> Regular gdb-7 reverse runs apps =A0 =A0 =A0 =A0 =A040,000x =A0 =A0 =A0 = =A0 =A0 =A0 =A0 =A0slower >>> UndoDB+gdb-7 reverse runs apps =A0 =A0 =A0 =A0 =A0 1.7x =A0 =A0 =A0 =A0= =A0 =A0slower! >>> >>> >>> Are you really do some try? >>> I suggest you do some test on it. =A0:) >>> >>> Thanks, >>> Hui >>> >>> On Fri, Dec 4, 2009 at 23:34, Sean Chen wrote: >>>> On UndoDb=92s website, I saw the following ad. >>>> >>>> Regular gdb-7 reverse runs apps 40,000x slower >>>> UndoDB+gdb-7 reverse runs apps 1.7x slower! >>>> >>>> In my experiment, gdb-7 reverse does run apps more than 20,000x >>>> slower. How does UndoDB improve the performance so much without a >>>> simulator and without record? Below is its self-introduction on the >>>> website. UndoDB's "snapshot-and-replay" technique stores periodic >>>> copy-on-write snapshots of the application and only non-deterministic >>>> inputs (system calls, thread-switches, shared memory reads, etc). >>>> >>>> Are there any obvious disadvantages in UndoDB? I tried to search >>>> UndoDB in the archive of the mailing list, however, little discussion >>>> is found. >>>> >>>> -- >>>> Best Regards, >>>> Sean Chen >>>> >>> >> >> That=92s UndoDB=92s ad on its website. >> >> In my experiment, gdb-7 reverse runs apps about 22,000x slower. >> >> -- >> Best Regards, >> Sean Chen >> > I also tried UndoDB, and it is really fast. So I am sure they are using different strategy. --=20 Best Regards, Sean Chen