SUNRPC: RPC metrics and RTT estimator should use same RTT value

Compute an RPC request's RTT once, and use that value both for reporting
RPC metrics, and for adjusting the RTT context used by the RPC client's RTT
estimator algorithm.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 8263f7aefedfb4e684b2de5f21779808a101eebe..04fc342d9840059cd351503c79ddb8ccd046aef9 100644 (file)
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -293,7 +293,6 @@ void                        xprt_set_retrans_timeout_rtt(struct rpc_task *task);
 void                   xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
 void                   xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
 void                   xprt_write_space(struct rpc_xprt *xprt);
-void                   xprt_update_rtt(struct rpc_task *task);
 void                   xprt_adjust_cwnd(struct rpc_task *task, int result);
 struct rpc_rqst *      xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
 void                   xprt_complete_rqst(struct rpc_task *task, int copied);

diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 6c9997ef386a1367a94c2afb3ec935d3d43c028e..698c627122944ce1d4310f904e17f0e1419ae4d8 100644 (file)
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -774,12 +774,7 @@ struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid)
 }
 EXPORT_SYMBOL_GPL(xprt_lookup_rqst);
 
-/**
- * xprt_update_rtt - update an RPC client's RTT state after receiving a reply
- * @task: RPC request that recently completed
- *
- */
-void xprt_update_rtt(struct rpc_task *task)
+static void xprt_update_rtt(struct rpc_task *task)
 {
        struct rpc_rqst *req = task->tk_rqstp;
        struct rpc_rtt *rtt = task->tk_client->cl_rtt;
@@ -787,12 +782,10 @@ void xprt_update_rtt(struct rpc_task *task)
 
        if (timer) {
                if (req->rq_ntrans == 1)
-                       rpc_update_rtt(rtt, timer,
-                                       (long)jiffies - req->rq_xtime);
+                       rpc_update_rtt(rtt, timer, task->tk_rtt);
                rpc_set_timeo(rtt, timer, req->rq_ntrans - 1);
        }
 }
-EXPORT_SYMBOL_GPL(xprt_update_rtt);
 
 /**
  * xprt_complete_rqst - called when reply processing is complete
@@ -811,6 +804,8 @@ void xprt_complete_rqst(struct rpc_task *task, int copied)
 
        xprt->stat.recvs++;
        task->tk_rtt = (long)jiffies - req->rq_xtime;
+       if (xprt->ops->timer != NULL)
+               xprt_update_rtt(task);
 
        list_del_init(&req->rq_list);
        req->rq_private_buf.len = copied;

diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 790a8f31b0bb926080f34217f2919cc2c97d3c31..3d1dcdf2aef10f6cf96a4cd9f6945d25a2f47ddf 100644 (file)
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -844,7 +844,6 @@ static void xs_udp_data_ready(struct sock *sk, int len)
        dst_confirm(skb_dst(skb));
 
        xprt_adjust_cwnd(task, copied);
-       xprt_update_rtt(task);
        xprt_complete_rqst(task, copied);
 
  out_unlock: