3rd path in series to update Cubic in conformation with RFC8312bis.
This update introduces the cubic_compute_pipe function.
2nd in series: D41667
This Diff is sliced from a summary patch provided by VMware to improve short RTT performance of Cubic.
Once all patches have been prepared and reviewed, they will go in together to make an atomic change
to cubic from pre-RFC status, to 8312bis status.
Submitted By: Bhaskar Pardeshi, VMware Inc.