irdma_attach_mcast(9)

📦 version 7.3.1, in nixpkgs unstable

💅 irdma_attach_mcast — bestie edition

Okay so real quick, the vibe check on this page: it's irdma_attach_mcast from the Kernel API Manual, section 9 — yes, irdma_attach_mcast(9), the kernel-api girly herself. 🎀 Buckle up, this one's short but the SEE ALSO list is a lot, and we do not skip a single name here. No cap.

✨ NAME ✨

irdma_attach_mcast — attach a qp to a multicast group 🫶

Like, you got a queue pair and you want it hanging out in a multicast group? That's literally the whole job. She's the one who does the attaching.

🦋 SYNOPSIS 🦋

int irdma_attach_mcast (struct ib_qp *ibqp , union ib_gid *ibgid , u16 lid );

Three things in, one int out. That's it. That's the whole function signature, and we are obsessed with her brevity. 💅

🌸 ARGUMENTS 🌸

Three arguments, each one a tiny main character:

  • ibqp — ptr to qp. Yep, a pointer to the qp you're attaching. That's the star of the show right there, the one getting added to the multicast group.
  • ibgid — pointer to global ID. The GID. The global identifier. She's the one that says which multicast group we're talking about.
  • lid — local ID. Just the LID, chillin' as a u16. Local ID things. 🫶
Not me having to say it plainly: ibqp is a struct ib_qp *, ibgid is a union ib_gid *, and lid is a u16. The types are right there in the synopsis, bestie, no guessing needed.

🔥 DESCRIPTION 🔥

returns error status.

That is genuinely the entire description and honestly, she ate. 💀 No lore, no backstory, no little paragraph about the hardware internals — the docs said what they said. Call it, get an error status back, move on with your life. Periodt.

👑 SEE ALSO 👑

Okay this is the part where the manpage decided to list everyone she's ever met. Source file first, because context:

  • Kernel file ./drivers/infiniband/hw/irdma/verbs.c

And now the full guest list, every single one in section (9), no cuts, no skips, all iconic:

Quick iykyk heads up: irdma_detach_mcast(9) is right there in the list. That's the opposite direction — she's the undo button for this whole situation. And note _irdma_destroy_qp(9) with the leading underscore is a different page from irdma_destroy_qp(9). Do not conflate them, bestie, they are siblings not twins. 💀

Also the SEE ALSO includes mcast_list_add(9), mcast_list_del(9), and mcast_list_lookup_ip(9) — the multicast list girlies. Go read them. They're doing the real work. ✨

🧚 sign-off 🧚

That's the whole page, bb! Source is ./drivers/infiniband/hw/irdma and the date on this baby is October 2026 — so she's fresh, she's documented, she's irdma_attach_mcast(9), and she's done. Go attach that qp to that multicast group. Slay. 🍓💜🌷⭐🌈🫶

📦 where this page comes from