[Cbe-oss-dev] PS3 performance analysis - errors on loading cellperfctr module

[Julio M. Merino Vidal]

On 12/12/2007, at 16:42, Uzi Shvadron wrote:

> On the PS3 (where I assume there is one user running one  
> application) there
> might not be a need for the PDT kernel module. The module is used to
> provide notifications on SPEs context switching. When the SPEs are  
> not over
> committed (that is, the number of SPE threads is smaller or equal  
> to the
> physical SPEs) there should be no context switching.
> So, if your program and environment meet the above requirements you  
> should
> be able to use PDT even if the kernel module is not installed and get
> useful trace that can be analyzed by PDTR and VPA.
>

But consider that many PS3 are being used for research, and in those  
cases it is not uncommon to try to simulate busy boxes to see how the  
applications behave when they are not alone.  At least that's what  
I'm doing now.

(And given that there is people porting all kinds of different  
applications to the Cell, with the primary focus on using them on the  
PS3, I can expect that there will be situations where the SPEs will  
be overcommitted.)

Cheers,

-- 
Julio M. Merino Vidal <jmerino at ac.upc.edu>