Re: real world reverse debugging success story

[Michael Snyder <msnyder@vmware.com>]

Michael Snyder wrote:
> Marc Khouzam wrote:
>> [...]
>>> Stats: used an 8 million instruction cache, running as a
>>> ring buffer.  Had to record over 80 million instructions
>>> before I tripped the bug.  Saved core file with record log
>>> was 250 megabytes, and reloaded fine.
>> Very impressive!
>>
>> How was the responsiveness?  I assume you didn't step
>> over all those instuctions ;-)  So, you must have run the program
>> and have it be recorded for a while.  I'm wondering if the execution
>> was annoyingly slow, or if it was ok.
> 
> The record phase was kind of slow, but I'm sure that was
> impacted by a very large number of notifications to the effect
> that process record would not record some memory because it
> could not get the segment register.
> 
> Replay was not bad at all, about 15 seconds to get from
> "goto-bookmark begin" to "goto-bookmark end".  For 80
> million instructions, that's about 5 million insns / sec.
> 
> Much faster than a first gen IBM PC, for instance!   ;-)

Oh, sorry, it was 8 million insns, so about 0.5M / sec.