STRUCT FQ_FLOW(9)

struct fq_flow(9) · Kernel API Manual 💅

🎀 NAME 🎀

struct fq_flow — the per traffic flow queue, bestie. Literally one queue for each traffic flow, that’s the whole assignment. ✨

✨ SYNOPSIS ✨

Okay so here’s the struct, and we are keeping it exact because we do not mess with code, periodt:

       struct fq_flow {
           struct fq_tin *tin;
           struct list_head flowchain;
           struct sk_buff_head queue;
           u32 backlog;
           int deficit;
        };

🫶 Members 🫶

• tin — owner of this flow. It’s for managing collisions, i.e. when a packet hashes to an index which points to a flow that is already owned by a different tin the packet is destined to. In such case the implementer must provide a fallback flow. yes bestie, a fallback flow is required, iykyk 💖
• flowchain — can be linked to fq_tin's new_flows or old_flows. Used for DRR++ (deficit round robin) based round robin queuing similar to the one found in net/sched/sch_fq_codel.c. same energy as that file, fr fr ✨
• queue — sk_buff queue to hold packets. the packets live here 💅
• backlog — number of bytes pending in the queue. The number of packets can be found in queue.qlen. bytes pending = backlog, packet count = queue.qlen 🔥
• deficit — used for DRR++. deficit round robin says hi 🦋

🔗 SEE ALSO 🔗

• Kernel file ./include/net/fq.h — also go say hi to struct fq_tin(9) and struct fq(9). 🌈

🌸 Source/version: ./include/net · Date: October 2026 · Page: struct fq_flow(9) — okay love u, bye bestie! 💖