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@xxxxxxxxxx>
---
net/sunrpc/xprt.c | 10 +++++-----
net/sunrpc/xprtsock.c | 15 +++++++++++++--
2 files changed, 18 insertions(+), 7 deletions(-)
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index fd8cb6d..35fc75e 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -723,6 +723,7 @@ 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
*
+ * Caller holds transport lock.
*/
void xprt_update_rtt(struct rpc_task *task)
{
@@ -732,8 +733,7 @@ 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);
}
}
@@ -750,12 +750,12 @@ void xprt_complete_rqst(struct rpc_task *task, int copied)
{
struct rpc_rqst *req = task->tk_rqstp;
+ task->tk_rtt = (long)jiffies - req->rq_xtime;
+ task->tk_xprt->stat.recvs++;
+
dprintk("RPC: %5u xid %08x complete (%d bytes received)\n",
task->tk_pid, ntohl(req->rq_xid), copied);
- task->tk_xprt->stat.recvs++;
- task->tk_rtt = (long)jiffies - req->rq_xtime;
-
list_del_init(&req->rq_list);
/* Ensure all writes are done before we update req->rq_received */
smp_wmb();
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 5c5491e..e4e276b 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -705,6 +705,18 @@ static int xs_tcp_send_request(struct rpc_task *task)
}
/**
+ * xs_udp_release_xprt - clean up after sending an RPC request via UDP
+ * @xprt: transport
+ * @task: rpc task
+ *
+ */
+static void xs_udp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
+{
+ xprt_update_rtt(task);
+ xprt_release_xprt_cong(xprt, task);
+}
+
+/**
* xs_tcp_release_xprt - clean up after a tcp transmission
* @xprt: transport
* @task: rpc task
@@ -856,7 +868,6 @@ static void xs_udp_data_ready(struct sock *sk, int len)
dst_confirm(skb->dst);
xprt_adjust_cwnd(task, copied);
- xprt_update_rtt(task);
xprt_complete_rqst(task, copied);
out_unlock:
@@ -1819,7 +1830,7 @@ static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
static struct rpc_xprt_ops xs_udp_ops = {
.set_buffer_size = xs_udp_set_buffer_size,
.reserve_xprt = xprt_reserve_xprt_cong,
- .release_xprt = xprt_release_xprt_cong,
+ .release_xprt = xs_udp_release_xprt,
.rpcbind = rpcb_getport_async,
.set_port = xs_set_port,
.connect = xs_connect,
--
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