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From: "D. Wythe" <alibuda@linux.alibaba.com>
To: "David S. Miller" <davem@davemloft.net>,
	Dust Li <dust.li@linux.alibaba.com>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Sidraya Jayagond <sidraya@linux.ibm.com>,
	Wenjia Zhang <wenjia@linux.ibm.com>
Cc: Mahanta Jambigi <mjambigi@linux.ibm.com>,
	Simon Horman <horms@kernel.org>,
	Tony Lu <tonylu@linux.alibaba.com>,
	Wen Gu <guwen@linux.alibaba.com>,
	linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org,
	linux-s390@vger.kernel.org, netdev@vger.kernel.org,
	oliver.yang@linux.alibaba.com, pasic@linux.ibm.com
Subject: [PATCH net-next 0/2] net/smc: transition to RDMA core CQ pooling
Date: Fri,  8 May 2026 14:37:16 +0800	[thread overview]
Message-ID: <20260508063718.101622-1-alibuda@linux.alibaba.com> (raw)

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/

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


             reply	other threads:[~2026-05-08  6:37 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-08  6:37 D. Wythe [this message]
2026-05-08  6:37 ` [PATCH net-next 1/2] net/smc: transition to RDMA core CQ pooling D. Wythe
2026-05-08  6:37 ` [PATCH net-next 2/2] net/smc: reduce TX slot contention with exclusive wait D. Wythe

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