UndoDB's performance

Sean Chen sean.chen1234@gmail.com
Tue Dec 15 07:26:00 GMT 2009


On Tue, Dec 15, 2009 at 11:56 AM, Hui Zhu <teawater@gmail.com> wrote:
> 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
>>
>

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?

-- 
Best Regards,
Sean Chen



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