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 8263f7a..04fc342 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 6c9997e..698c627 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 790a8f3..3d1dcdf 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: