RDMA_SET_LOCAL_ECE(3)

💅 RDMA_SET_LOCAL_ECE 💅

okay so bestie, this is the librdmacm Programmer's Manual page for rdma_set_local_ece, and we're gonna get you so comfy with it. it's giving "niche but important" and honestly? iconic.

---

✨ NAME ✨

rdma_set_local_ece — Set local ECE paraemters to be used for REQ/REP communication.

(and yes, "paraemters" is literally what the page says, we don't fix typos in this house, we respect the artifact 💀)

---

🦋 SYNOPSIS 🦋

#include <rdma/rdma_cma.h>

int rdma_set_local_ece(struct rdma_cm_id *id, struct ibv_ece *ece);

---

🌸 DESCRIPTION 🌸

so rdma_set_local_ece() sets local ECE parameters. that's the whole vibe. ✨

this function is suppose to be used by the users of external QPs (again, the original says "suppose", we're just the messenger 🫶). the call needs to be performed before replying to the peer, and it's needed to configure RDMA_CM with the desired ECE options.

the thing is — being used by external QP and RDMA_CM doesn't manage that QP, so the peer needs to call to libibverbs API by itself. no hand-holding here, you're on your own for that part, iykyk.

⚠️ reminder: call it before you reply to the peer. timing matters, bestie, it's giving "main character energy" but the main character is the ordering of your syscalls.

🎀 the usual flow for the passive side 🎀

• ibv_create_qp() <- create data QP.
• ece = ibv_query_ece() <- get ECE from libibvers provider.
• rdma_set_local_ece(ece) <- set desired ECE options.
• rdma_connect() <- send connection request
• ece = rdma_get_remote_ece() <- get ECE options from remote peer
• ibv_set_ece(ece) <- set local ECE options with data received from the peer.
• ibv_modify_qp() <- enable data QP.
• rdma_accept()/rdma_establish()/rdma_reject_ece()

like, look at that little pipeline. lowkey beautiful. 🔥

---

🌈 ARGUMENTS 🌈

• id — RDMA communication identifier.
• *ece — ECE parameters.

---

⭐ RETURN VALUE ⭐

rdma_set_local_ece() returns 0 on success, or -1 on error. if an error occurs, errno will be set to indicate the failure reason. so like, check your return values, bestie, don't be out here ignoring -1 😭

---

💜 SEE ALSO 💜

• rdma_cm(7)
• rdma_get_remote_ece(3)

---

👑 AUTHOR 👑

Leon Romanovsky <leonro@mellanox.com>

---

and that's the page!! 🎀 this whole thing came to you from the librdmacm crew, dated 2020-02-02 — yeah it's a little vintage, but it still slays. go forth and set those local ECE parameters, bestie 💅✨🦋