@Harvy66:
"I have been saying HFSC schedules both inter-queue and intra-queue. If HFSC does no Fair Queueing intra-queue then any flow could saturate a queue."
HFSC does not do anything with flows, it does not do hashing, it doesn't do anything with IP, nothing. All it does is pull the head packet from a child queue and decide which queue goes next. It's a queue scheduler.
Fair queuing, in the context of a queue, fights buffer bloat by isolating flows from each other within the queue.
Fair queuing, in the context of a scheduler, gives a fair amount of resources between queues.
Both HFSC and fq_CoDel do "fair queuing" at different levels.
No. Fair Queueing is exclusively concerned with flows.
https://en.m.wikipedia.org/wiki/Fair_queuing
Fair queuing is a family of scheduling algorithms used in some process and network schedulers. The concept implies a separate data packet queue (or job queue) for each traffic flow (or for each program process) as opposed to the traditional approach with one FIFO queue for all packet flows (or for all process jobs). The purpose is to achieve fairness when a limited resource is shared, for example to avoid that flows with large packets (or processes that generate small jobs) achieve more throughput (or CPU time) than other flows (or processes).
To claim "Fair Queueing", you must separate all flows (or most of the flows, like with SFQ). Above, it says each flow gets a "separate data packet queue", meaning this is automatic and not dependant on the user manually separating the flows like your "pseudo fair-queueing" setup. HFSC is a Fair Queueing algo therefore it separates all flows, by definition.
HFSC cites many other Fair Queueing algorithms including one paper which all modern Fair Queueing algorithms attempt to approximate as closely as possible, and it is titled "A generalized processor sharing approach to flow control in integrated services networks".
For the sake of clarity, the definition of a "flow" can be found here: https://en.m.wikipedia.org/wiki/Traffic_flow_(computer_networking)
Do me a favor and read the Generalized Processor Sharing paper (or even just the wikipedia entry) along with some papers cited by HFSC and any other academic papers you can find concerning Fair Queueing. Confirm or disprove your suspicions before replying. I have read all HFSC-cited papers and dozens of related papers and I can assure you that your posts in this thread are mostly misinformation.
Edit: Fixed link, trimmed cruft.