Implementing selective cache injection

A method for implementing memory hierarchy placement decisions in a memory system in a computer system comprising:

• providing a memory controller in the memory system;
• providing an in-memory processing element in the memory system;
• receiving first data from an input output (IO) device and receiving second data exchanged over a network;
• routing arriving first data and second data directly into the memory system;
• selectively injecting the first data and the second data into a processor cache;
• and
• using one of said memory controller and said in-memory processing element in the memory system, selectively driving data placement into a level of the memory hierarchy based upon the arrival of first data from said input output (IO) device, and from one of computation and a directive of said in-memory processing element.