commit bbc72cea58f671665b6362be0d4e391813ac0eee
author Chuck Lever <chuck.lever@oracle.com> Fri May 07 13:34:27 2010 -0400
committer Trond Myklebust <Trond.Myklebust@netapp.com> Fri May 14 15:09:32 2010 -0400
tree e70a35d3bc05ece4a532514893fec151aee2bd46
parent 9bc4e3ca46e4eb9cb434de4175c6041d00bbdca3

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>

include/linux/sunrpc/xprt.h

diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 8263f7a..04fc342 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -293,7 +293,6 @@
 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);

net/sunrpc/xprt.c

diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 6c9997e..698c627 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -774,12 +774,7 @@
 }
 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 @@
 
 	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 @@
 
 	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;

net/sunrpc/xprtsock.c

diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 790a8f3..3d1dcdf 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -844,7 +844,6 @@
 	dst_confirm(skb_dst(skb));
 
 	xprt_adjust_cwnd(task, copied);
-	xprt_update_rtt(task);
 	xprt_complete_rqst(task, copied);
 
  out_unlock: