Re: UndoDB's performance

[Hui Zhu <teawater@gmail.com>]

I did some test but its speed close to prec.  Some others was better.
Maybe it have some special performance technology for some code.

Hui

On Tue, Dec 15, 2009 at 10:40, Sean Chen <sean.chen1234@gmail.com> wrote:
> On Mon, Dec 14, 2009 at 11:07 PM, Hui Zhu <teawater@gmail.com> wrote:
>> Try undodb.
>>
>> On Mon, Dec 14, 2009 at 21:18, Sean Chen <sean.chen1234@gmail.com> wrote:
>>> On Mon, Dec 14, 2009 at 7:14 PM, Hui Zhu <teawater@gmail.com> wrote:
>>>> gdb-7 reverse debugging accelerator.
>>>> Regular gdb-7 reverse runs apps          40,000x                slower
>>>> UndoDB+gdb-7 reverse runs apps           1.7x            slower!
>>>>
>>>>
>>>> Are you really do some try?
>>>> I suggest you do some test on it.  :)
>>>>
>>>> Thanks,
>>>> Hui
>>>>
>>>> On Fri, Dec 4, 2009 at 23:34, Sean Chen <sean.chen1234@gmail.com> wrote:
>>>>> On UndoDb’s 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’s UndoDB’s 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
>