Re: porting reversible on arm/mips

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

On Fri, Dec 11, 2009 at 4:15 PM, Jakob Engblom <jakob@virtutech.com> wrote:
>> I was interested in the porting on ARM. But later I found that the
>> performance impact on ARM might damage the usage of process record. In
>> my experiment, reversible debugging is about 20000x slower, which
>> might be endurable on the modern computer. However, ARM target is tens
>> of times (or even more if we consider the memory) slower than PC. So
>> recording instructions will be very slow, about thousands of
>> instructions per second.
>
> I just must pitch in and say that it depends on the simulator.
>
> An advantage to using a full simulator is that you simplify the system and no
> longer have to care about OS calls: the OS is just part of the context you save
> and reverse.  So the overhead actually goes down compared to native prec.  I
> think a reversible ARM simulator can be made to run within a factor of ten of
> native speed, easily.
>
>
> Best regards,
>
> /jakob
>
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The performance of reversible debugging with simulator build-in
support should not be so low. But if Oza means reversible debugging
with process record, performance will be the truth we have to face.

-- 
Best Regards,
Sean Chen