SUNRPC: Add a separate spinlock to protect the RPC request receive list
This further reduces contention with the transport_lock, and allows us
to convert to using a non-bh-safe spinlock, since the list is now never
accessed from a bh context.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 3eb9ec1..2af189c 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -872,17 +872,17 @@
}
static void xprt_wait_on_pinned_rqst(struct rpc_rqst *req)
-__must_hold(&req->rq_xprt->transport_lock)
+__must_hold(&req->rq_xprt->recv_lock)
{
struct rpc_task *task = req->rq_task;
if (task && test_bit(RPC_TASK_MSG_RECV, &task->tk_runstate)) {
- spin_unlock_bh(&req->rq_xprt->transport_lock);
+ spin_unlock(&req->rq_xprt->recv_lock);
set_bit(RPC_TASK_MSG_RECV_WAIT, &task->tk_runstate);
wait_on_bit(&task->tk_runstate, RPC_TASK_MSG_RECV,
TASK_UNINTERRUPTIBLE);
clear_bit(RPC_TASK_MSG_RECV_WAIT, &task->tk_runstate);
- spin_lock_bh(&req->rq_xprt->transport_lock);
+ spin_lock(&req->rq_xprt->recv_lock);
}
}
@@ -1008,13 +1008,13 @@
/*
* Add to the list only if we're expecting a reply
*/
- spin_lock_bh(&xprt->transport_lock);
/* Update the softirq receive buffer */
memcpy(&req->rq_private_buf, &req->rq_rcv_buf,
sizeof(req->rq_private_buf));
/* Add request to the receive list */
+ spin_lock(&xprt->recv_lock);
list_add_tail(&req->rq_list, &xprt->recv);
- spin_unlock_bh(&xprt->transport_lock);
+ spin_unlock(&xprt->recv_lock);
xprt_reset_majortimeo(req);
/* Turn off autodisconnect */
del_singleshot_timer_sync(&xprt->timer);
@@ -1329,15 +1329,18 @@
task->tk_ops->rpc_count_stats(task, task->tk_calldata);
else if (task->tk_client)
rpc_count_iostats(task, task->tk_client->cl_metrics);
+ spin_lock(&xprt->recv_lock);
+ if (!list_empty(&req->rq_list)) {
+ list_del(&req->rq_list);
+ xprt_wait_on_pinned_rqst(req);
+ }
+ spin_unlock(&xprt->recv_lock);
spin_lock_bh(&xprt->transport_lock);
xprt->ops->release_xprt(xprt, task);
if (xprt->ops->release_request)
xprt->ops->release_request(task);
- if (!list_empty(&req->rq_list))
- list_del(&req->rq_list);
xprt->last_used = jiffies;
xprt_schedule_autodisconnect(xprt);
- xprt_wait_on_pinned_rqst(req);
spin_unlock_bh(&xprt->transport_lock);
if (req->rq_buffer)
xprt->ops->buf_free(task);
@@ -1361,6 +1364,7 @@
spin_lock_init(&xprt->transport_lock);
spin_lock_init(&xprt->reserve_lock);
+ spin_lock_init(&xprt->recv_lock);
INIT_LIST_HEAD(&xprt->free);
INIT_LIST_HEAD(&xprt->recv);