Subj : Re: What is the real costs of LOCK on x86 multiprocesor machine?
To   : comp.programming.threads
From : Joe Seigh
Date : Sun Jul 31 2005 08:43 am

Peter Dimov wrote:
> Mirek Fidler wrote:
> 
>>>In practice, the actual amortized cost appears to be much lower than
>>>50-100x. I see a 4x difference on shared_ptr_timing_test (which
>>>basically tests reference count increments and decrements in a somewhat
>>>real-life worst case scenario.)
>>
>>Have you tested on real MP machine? (4x is close to what I have measured
>>on my SP).
> 
> 
> No, it was a single P4/2GHz without HT.
> 

Now that a lot of people have weighed in on this, why does the cost of
atomic increment/decrement matter?

-- 
Joe Seigh

When you get lemons, you make lemonade.
When you get hardware, you make software.

.