ud_loopback(9)

💅 NAME

okay so this is the ud_loopback(9) page from the Kernel API Manual, bestie, and the whole vibe is: handle send on loopback QPs ✨

✨ SYNOPSIS

the signature is literally:

void ud_loopback (struct rvt_qp *sqp , struct rvt_swqe *swqe );

🎀 ARGUMENTS

• sqp — the sending QP 👑
• swqe — the send work request 💌

🦋 DESCRIPTION

so this gets called from hfi1_make_ud_req to forward a WQE addressed to the same HFI 🫶

heads up bestie: the receive interrupt handler may be calling hfi1_ud_rcv while this is being called 😭 so yeah, keep that in mind.

🌈 SEE ALSO

• Kernel file ./drivers/infiniband/hw/hfi1/ud.c
• hfi1_make_ud_req(9)
• hfi1_ud_rcv(9)

mwah 💋 this lil page lives under ./drivers/infiniband/hw/hfi1, stamped October 2026, and it’s the ud_loopback(9) manual page, bestie 🫶✨