SUNRPC: RPC transport queue must be low latency

rpciod can easily get congested due to the long list of queued rpc_tasks.
Having the receive queue wait in turn for those tasks to complete can
therefore be a bottleneck.

Address the problem by separating the workqueues into:
- rpciod: manages rpc_tasks
- xprtiod: manages transport related work.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Trond Myklebust
2016-05-27 10:39:50 -04:00
parent 5157b95696
commit 40a5f1b19b
4 changed files with 28 additions and 11 deletions

View File

@@ -220,7 +220,7 @@ static void xprt_clear_locked(struct rpc_xprt *xprt)
clear_bit(XPRT_LOCKED, &xprt->state);
smp_mb__after_atomic();
} else
queue_work(rpciod_workqueue, &xprt->task_cleanup);
queue_work(xprtiod_workqueue, &xprt->task_cleanup);
}
/*
@@ -645,7 +645,7 @@ void xprt_force_disconnect(struct rpc_xprt *xprt)
set_bit(XPRT_CLOSE_WAIT, &xprt->state);
/* Try to schedule an autoclose RPC call */
if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
queue_work(rpciod_workqueue, &xprt->task_cleanup);
queue_work(xprtiod_workqueue, &xprt->task_cleanup);
xprt_wake_pending_tasks(xprt, -EAGAIN);
spin_unlock_bh(&xprt->transport_lock);
}
@@ -672,7 +672,7 @@ void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie)
set_bit(XPRT_CLOSE_WAIT, &xprt->state);
/* Try to schedule an autoclose RPC call */
if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
queue_work(rpciod_workqueue, &xprt->task_cleanup);
queue_work(xprtiod_workqueue, &xprt->task_cleanup);
xprt_wake_pending_tasks(xprt, -EAGAIN);
out:
spin_unlock_bh(&xprt->transport_lock);
@@ -689,7 +689,7 @@ xprt_init_autodisconnect(unsigned long data)
if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
goto out_abort;
spin_unlock(&xprt->transport_lock);
queue_work(rpciod_workqueue, &xprt->task_cleanup);
queue_work(xprtiod_workqueue, &xprt->task_cleanup);
return;
out_abort:
spin_unlock(&xprt->transport_lock);