From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 7105 invoked by alias); 15 Dec 2009 07:26:27 -0000 Received: (qmail 7089 invoked by uid 22791); 15 Dec 2009 07:26:25 -0000 X-SWARE-Spam-Status: No, hits=-1.4 required=5.0 tests=AWL,BAYES_00,SARE_MSGID_LONG40,SPF_PASS X-Spam-Check-By: sourceware.org Received: from ey-out-1920.google.com (HELO ey-out-1920.google.com) (74.125.78.148) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 15 Dec 2009 07:26:19 +0000 Received: by ey-out-1920.google.com with SMTP id 5so850926eyb.42 for ; Mon, 14 Dec 2009 23:26:16 -0800 (PST) MIME-Version: 1.0 Received: by 10.213.110.17 with SMTP id l17mr6674099ebp.91.1260861976339; Mon, 14 Dec 2009 23:26:16 -0800 (PST) In-Reply-To: References: <5e81cb500912040734u5ce67afdpd6a2d0e63173f908@mail.gmail.com> <5e81cb500912140518r2ad3f2fdrd0dd5a546e6d8a33@mail.gmail.com> <5e81cb500912141840s389859c2r9c56dd8800adb731@mail.gmail.com> Date: Tue, 15 Dec 2009 07:26:00 -0000 Message-ID: <5e81cb500912142326t1bd545ek9180661d8bac10fe@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/msg00092.txt.bz2 On Tue, Dec 15, 2009 at 11:56 AM, Hui Zhu wrote: > I did some test but its speed close to prec. =A0Some others was better. > Maybe it have some special performance technology for some code. > > Hui > > On Tue, Dec 15, 2009 at 10:40, Sean Chen wrote: >> On Mon, Dec 14, 2009 at 11:07 PM, Hui Zhu wrote: >>> Try undodb. >>> >>> On Mon, Dec 14, 2009 at 21:18, Sean Chen wrot= e: >>>> 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 wro= te: >>>>>> 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. >> >> -- >> Best Regards, >> Sean Chen >> > It might not use process record technique like your design. Below is its self-introduction on its 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). Any comments? --=20 Best Regards, Sean Chen