Question about Parallel Programming

[nge]

Dear All,
I have a question about parallel programming. In some programming languages, we can do some part of the code to execute in parallel, but what I'm confusing is how these codes run on a processor (say, normal intel p4), time scheduling or what? thanks

nge

 

[Ace-X]

For program it is considered as execution on different processors. But actually, these processors are virtual - just simple time division. Let say, 1 ms real processor executes commands for first virtual processor, then 1 ms for second virtual, etc.

Also, there are some techniques, like HyperThreading from Intel, that can simultaneuosly execute 2 and more instructions for parallel threads on the same hardware processor. This approach can be applied only when these instructions from parallel threads require different resources of processor.

 

[brmadhukar]

Hi,
Some times (as in SIMD) architecture the processor runs in Time division but appears parallel for all practical purposes. In some processors there are multiple execution units.
B R M