Re: Odd performance results

[Peter Zijlstra]

On 10 July 2016 06:26:39 CEST, "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> wrote:
>Hello!
>
>So I ran a quick benchmark which showed stair-step results.  I
>immediately
>thought "Ah, this is due to CPU 0 and 1, 2 and 3, 4 and 5, and 6 and 7
>being threads in a core."  Then I thought "Wait, this is an x86!"
>Then I dumped out cpu*/topology/thread_siblings_list, getting the
>following:
>
>	cpu0/topology/thread_siblings_list: 0-1
>	cpu1/topology/thread_siblings_list: 0-1
>	cpu2/topology/thread_siblings_list: 2-3
>	cpu3/topology/thread_siblings_list: 2-3
>	cpu4/topology/thread_siblings_list: 4-5
>	cpu5/topology/thread_siblings_list: 4-5
>	cpu6/topology/thread_siblings_list: 6-7
>	cpu7/topology/thread_siblings_list: 6-7


I'm guessing this is an AMD bulldozer like machine?
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.