[PATCH RFC 8/8] SUNRPC: Reduce xprtiod workqueue contention

[Chuck Lever <cel@kernel.org>]

xprtiod handles transport-level operations: socket receive
processing, error recovery, and connection lifecycle. On systems
driving heavy NFS traffic, these operations contend on the UNBOUND
worker pool lock just as rpciod does.

Set WQ_AFFN_SMT on the xprtiod workqueue to give each SMT group its
own pool and lock.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Chuck Lever <cel@kernel.org>
---
 net/sunrpc/sched.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index b84af2c0b104..3236dfdb4096 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -1304,6 +1304,7 @@ static int rpciod_start(void)
 	wq = alloc_workqueue("xprtiod", wq_flags, 0);
 	if (!wq)
 		goto free_rpciod;
+	rpc_set_wq_smt_affinity(wq, "xprtiod");
 	xprtiod_workqueue = wq;
 	return 1;
 free_rpciod:

-- 
2.55.0