Re: UndoDB's performance

[Sean Chen <sean.chen1234@gmail.com>]

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