Subj : Re: Lock Free -- where to start
To   : comp.programming.threads
From : Joe Seigh
Date : Thu Sep 29 2005 03:11 pm

Michel wrote:
> Joe Seigh wrote:
> 
>> That would be for a small number of threads.  If probability of lock 
>> contention
>> for a single thread is .001 in your example, then for 100 threads it's 
>> about
>> ..100, 200 threads about .199, 1000 threads about .630, etc...
>>
>> Lock-free is about scalability, not the actual overhead.   If you know 
>> your
>> application will never experience high contention or you don't care about
>> scalability then you should stick with conventional lock based solutions.
> 
> 
> 
> Wouldn't you say there is a design or structural problem having 100-1000 
> threads contending for the same lock in any somewhat ordinary 
> application at the server or the client side? Wouldn't context switching 
> drain the performance anyways?
> 
Depends on how many processors you have.  There may be other things causing
context switching also but blocking on a lock certainly isn't going to help
performance.


-- 
Joe Seigh

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

.