Re: Possible bug from kernel 2.6.22 and above, 2.6.24-rc4

[Ingo Molnar <mingo@elte.hu>]

* Jie Chen <chen@jlab.org> wrote:

>> sorry to be dense, but could you give me instructions how i could 
>> remove the affinity mask and test the "barrier overhead" myself? I 
>> have built "pthread_sync" and it outputs numbers for me - which one 
>> would be the barrier overhead: Reference_time_1 ?
>
> To disable affinity, do configure --enable-public-release 
> --disable-thread_affinity. You should see barrier overhead like the 
> following: Computing BARRIER time
>
> Sample_size  Average     Min    Max          S.D.        Outliers
>  20      19.486162   19.482250   19.491400    0.002740      0
>
> BARRIER time =        19.486162 microseconds +/- 0.005371
> BARRIER overhead =    8.996257 microseconds +/- 0.006575

ok, i did that and rebuilt. I also did "make check" and got 
src/pthread_sync which i can run. The only thing i'm missing, if i run 
src/pthread_sync, it outputs "PARALLEL time":

 PARALLEL time =                           22.486103 microseconds +/- 3.944821
 PARALLEL overhead =                       10.638658 microseconds +/- 10.854154

not "BARRIER time". I've re-read the discussion and found no hint about 
how to build and run a barrier test. Either i missed it or it's so 
obvious to you that you didnt mention it :-)

	Ingo