Threads and memory management

Simon Marlow marlowsd at
Tue Apr 28 05:27:53 EDT 2009

On 27/04/2009 11:29, Bulat Ziganshin wrote:
> Hello Simon,
> Monday, April 27, 2009, 2:13:26 PM, you wrote:
>> This is a very strange result: the user time should not *decrease*, but
>> rather should stay the same or increase a bit when adding cores.  If
> ability to run two threads simultaneous may increase performance in
> some scenarios. one example is consumer+producer threads. with 2
> OS threads all produced data are consumed immediately, so we live
> inside L2 cache. with 1 OS thread produced data overflow the cache
> before threads are switched, making execution much slower

Yes, good point.  Though I'd be surprised if that was happening here.


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