rvt_qp_wqe_unreserve(9)

💅 rvt_qp_wqe_unreserve(9)

okay bestie, welcome to the Kernel API Manual — this is the page for rvt_qp_wqe_unreserve(9), and it's basically the little cleanup step that says “we're done reserving, bestie.” ✨

🎀 NAME 🎀

rvt_qp_wqe_unreserve — clean reserved operation 🧼

🌸 SYNOPSIS 🌸

void rvt_qp_wqe_unreserve (struct rvt_qp *qp , int flags );

🦋 ARGUMENTS 🦋

• qp — the rvt qp. that's the star of the show here 💅
• flags — send wqe flags. yes, those flags 🎀

🔥 DESCRIPTION 🔥

so what does it actually do? this decrements the reserve use count. that's the whole vibe. iconic, lowkey crucial. 💖

okay this part is MUST-level important: this call MUST precede the change to s_last to insure that post send sees a stable s_avail. no cap, the order matters. 😭

an smp_mp__after_atomic is used to insure the compiler does not juggle the order of the s_last ring index and the decrementing of s_reserved_used. literally keeping the compiler from doing chaotic little reorder shenanigans. 🫶

👑 SEE ALSO 👑

the whole squad, fr fr:

• Kernel file ./include/rdma/rdmavt_qp.h
• struct rvt_ud_wr(9)
• struct rvt_krwq(9)
• rvt_get_swqe_ah_attr(9)
• rvt_get_swqe_remote_qpn(9)
• rvt_get_swqe_remote_qkey(9)
• rvt_get_swqe_pkey_index(9)
• rvt_get_rq_count(9)
• struct rvt_operation_params(9)
• rvt_is_user_qp(9)
• rvt_get_qp(9)
• rvt_put_qp(9)
• rvt_put_swqe(9)
• rvt_qp_wqe_reserve(9)
• rvt_div_round_up_mtu(9)
• rvt_div_mtu(9)
• rvt_timeout_to_jiffies(9)
• rvt_lookup_qpn(9)
• rvt_mod_retry_timer_ext(9)
• rvt_put_qp_swqe(9)
• rvt_qp_swqe_incr(9)
• rvt_recv_cq(9)
• rvt_send_cq(9)
• rvt_qp_complete_swqe(9)
• struct rvt_qp_iter(9)
• ib_cq_tail(9)
• ib_cq_head(9)
• rvt_free_rq(9)
• rvt_to_iport(9)
• rvt_rc_credit_avail(9)

mwah 💖 source/version: ./include/rdma; date: October 2026 — bye bestie! 🫶