[PATCH net-next 0/2] net/smc: transition to RDMA core CQ pooling
From: "D. Wythe" <alibuda@linux.alibaba.com>
Date: 2026-05-28 08:48:27
Also in:
linux-rdma, linux-s390, lkml
This series transitions SMC-R completion handling to RDMA core CQ pooling via the ib_cqe API. The new completion model improves scalability by allowing per-link completion processing across multiple cores and enables DIM-based interrupt moderation. As a side effect, the increased concurrency can amplify contention for TX slots on the shared wait queue. Patch 2 addresses this by switching TX slot allocation from non-exclusive wait_event() to prepare_to_wait_exclusive(), which avoids thundering-herd wakeups under contention. Patch 1 replaces the global per-device CQ and manual tasklet polling model with RDMA core CQ pooling. Patch 2 reduces TX slot contention by using exclusive wait queue entries during allocation. Link: https://lore.kernel.org/netdev/20260305022323.96125-1-alibuda@linux.alibaba.com/ (local) --- Changes v1 -> v2: https://lore.kernel.org/netdev/20260508063718.101622-1-alibuda@linux.alibaba.com/ (local) 1. remove unnecessary inline from static CQE init helpers. 2. Use ib_drain_qp() with +1 max_send_wr; 3. Fix v2 state clearing. 4. Add re-check after schedule_timeout() to fix timeout/signal races. D. Wythe (2): net/smc: transition to RDMA core CQ pooling net/smc: reduce TX slot contention with exclusive wait net/smc/smc_core.c | 9 +- net/smc/smc_core.h | 28 ++-- net/smc/smc_ib.c | 113 +++++---------- net/smc/smc_ib.h | 7 - net/smc/smc_tx.c | 1 - net/smc/smc_wr.c | 344 ++++++++++++++++++++------------------------- net/smc/smc_wr.h | 40 ++---- 7 files changed, 215 insertions(+), 327 deletions(-) -- 2.45.0