Re: -O option causing test jitter?

[Nivedita Singhvi <niv@us.ibm.com>]

Steven Rostedt wrote:
> 
> On Thu, 17 Apr 2008, john stultz wrote:
>> Anyway, I wanted to hit the list with this so folks could look at it and
>> let me know if such severe jitter was expected from just compile
>> options?
>>
> 
> I think this may simply be a simple case of cache misses.
> 
> Attached is two files: sched_jitter-test.c and do_work.S. I found that by
> switching the positions of do_work1 and do_work2, which ever one is first
> performs better. do_work1 is me copying the output of objdump of -O1 of
> do_work, and do_work2 is copying the output from objdump of -O2.

So jitter going down might simply be a case of the
faster cases actually slowing down, right - and
making things uniformly slow?

Do we know if the whole kaboodle is getting faster?

thanks,
Nivedita