[PATCH net-next v3 12/13] net/rds: drop rds_conn_count in favor of t_conn_count
From: Allison Henderson <achender@kernel.org>
Date: 2026-09-14 03:37:26
Also in:
linux-rdma
Subsystem:
networking [general], rds - reliable datagram sockets, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Allison Henderson, Linus Torvalds
The previous patch gave each transport its own connection count in t_conn_count, incremented and decremented at exactly the points where the global rds_conn_count is. That leaves rds_conn_count with a single remaining consumer: the seed of the per-path workqueue names in __rds_conn_create(). Switch the name seed to t_conn_count, as UEK does, and remove rds_conn_count. The numbering becomes per-transport instead of global, so connections of different transports can now receive the same seed; workqueue names carry no uniqueness requirement, and the seed was already reused as the count rose and fell. Removing the counter also removes the rds_conn_lock round-trip that rds_conn_destroy_fini() took solely to decrement it, leaving the free path lock-free. Based on the Oracle UEK commit "net/rds: Each RDS transport should keep its own connection count". Assisted-by: Claude-Code:claude-fable-5 Signed-off-by: Allison Henderson <achender@kernel.org> --- net/rds/connection.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-)
diff --git a/net/rds/connection.c b/net/rds/connection.c
index e5a8534c23cf..f5f25e4a53b9 100644
--- a/net/rds/connection.c
+++ b/net/rds/connection.c@@ -47,7 +47,6 @@ /* converting this to RCU is a chore for another day.. */ static DEFINE_SPINLOCK(rds_conn_lock); -static unsigned long rds_conn_count; /* woken whenever a transport's t_conn_count drops to zero */ static DECLARE_WAIT_QUEUE_HEAD(rds_conn_freed_waitq); static struct hlist_head rds_conn_hash[RDS_CONNECTION_HASH_ENTRIES];
@@ -332,12 +331,13 @@ static struct rds_connection *__rds_conn_create(struct net *net, init_waitqueue_head(&conn->c_hs_waitq); for (i = 0; i < npaths; i++) { + int seq = atomic_read(&trans->t_conn_count); + __rds_conn_path_init(conn, &conn->c_path[i], is_outgoing); conn->c_path[i].cp_index = i; conn->c_path[i].cp_wq = - alloc_ordered_workqueue("krds_cp_wq#%lu/%d", 0, - rds_conn_count, i); + alloc_ordered_workqueue("krds_cp_wq#%d/%d", 0, seq, i); if (!conn->c_path[i].cp_wq) conn->c_path[i].cp_wq = rds_wq; }
@@ -408,7 +408,6 @@ static struct rds_connection *__rds_conn_create(struct net *net, rds_conn_get(conn); /* caller */ rcu_assign_pointer(parent->c_passive, conn); rds_cong_add_conn(conn); - rds_conn_count++; atomic_inc(&conn->c_trans->t_conn_count); } } else {
@@ -431,7 +430,6 @@ static struct rds_connection *__rds_conn_create(struct net *net, rds_conn_get(conn); hlist_add_head_rcu(&conn->c_hash_node, head); rds_cong_add_conn(conn); - rds_conn_count++; atomic_inc(&conn->c_trans->t_conn_count); } }
@@ -669,7 +667,6 @@ static void rds_conn_destroy_fini(struct kref *kref) c_refcount); int npaths = (conn->c_trans->t_mp_capable ? RDS_MPATH_WORKERS : 1); struct rds_transport *trans = conn->c_trans; - unsigned long flags; int i; for (i = 0; i < npaths; i++)
@@ -678,10 +675,6 @@ static void rds_conn_destroy_fini(struct kref *kref) kfree(conn->c_path); kmem_cache_free(rds_conn_slab, conn); - spin_lock_irqsave(&rds_conn_lock, flags); - rds_conn_count--; - spin_unlock_irqrestore(&rds_conn_lock, flags); - /* only after everything the transport module owns has been * freed above may its unload proceed */
--
2.25.1