[Cbe-oss-dev] Costs of the SPE Context Switch

[gelliott]

I have recently been familiarizing myself with the Cell architecture and 
I am interested the costs of SPE context switches on Linux.  The 
material I have found states that the cost of the context switch 
operation is relatively high (compared to a standard CPU) and is on the 
order of 20 microseconds.

The Cell BE Programming Handbook has a chapter (12) on the steps needed 
to carry out an SPE context switch.  I'd like to find benchmarks as 
fine-grained as possible (perhaps paralleling the Handbook's steps), but 
I would be happy with numbers characterizing the average costs of 
managing the SPE Local Store, Registers, and DMA queue.

Does anyone know if such information is available?  If not, can anyone 
suggest the best method to capture such data?  Any intuition on these 
more fine-grain costs?

Thank you,
Glenn