Re: pthreads condition variables

[Jean-Yves Migeon <jeanyves.migeon%free.fr@localhost>]

On Thu, 19 Nov 2009 14:52:25 +0000, raymond.meyer%rambler.ru@localhost wrote:
> On Thu, 19 Nov 2009 15:28:16 +0100
> Jean-Yves Migeon <jeanyves.migeon%free.fr@localhost> wrote:
> 
>> Something like:
>> while (atomic_cas(...there_is_nothing_to_do...))
>>     sched_yield();
> 
> How does atomic_cas affect performance? If machine supports hadware cas
> instruction, does it suspend all cores/processors from fetching data
> because it locks address/data bus, or does it suspend only those
> cores/processors which are trying to read/modify the same address on
> which cas is operating at that time instance?

http://download.intel.com/design/processor/manuals/253668.pdf

8.1, "Locked atomic operations". Happy reading :o

Remember: "premature optimization is..."

-- 
Jean-Yves Migeon
jeanyves.migeon%free.fr@localhost