From: Chuck Lever <chuck.lever@xxxxxxxxxx> commit 8729aaba74626c4ebce3abf1b9e96bb62d2958ca upstream. I noticed that for callback requests, the reported backlog latency is always zero, and the rtt value is crazy big. The problem was that rqst->rq_xtime is never set for backchannel requests. Fixes: 78215759e20d ("SUNRPC: Make RTT measurement more ... ") Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/sunrpc/xprtrdma/svc_rdma_backchannel.c | 1 + net/sunrpc/xprtsock.c | 3 ++- 2 files changed, 3 insertions(+), 1 deletion(-) --- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c +++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c @@ -195,6 +195,7 @@ rpcrdma_bc_send_request(struct svcxprt_r pr_info("%s: %*ph\n", __func__, 64, rqst->rq_buffer); #endif + rqst->rq_xtime = ktime_get(); rc = svc_rdma_bc_sendto(rdma, rqst, ctxt); if (rc) { svc_rdma_send_ctxt_put(rdma, ctxt); --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -2659,6 +2659,8 @@ static int bc_sendto(struct rpc_rqst *re .iov_len = sizeof(marker), }; + req->rq_xtime = ktime_get(); + len = kernel_sendmsg(transport->sock, &msg, &iov, 1, iov.iov_len); if (len != iov.iov_len) return -EAGAIN; @@ -2684,7 +2686,6 @@ static int bc_send_request(struct rpc_rq struct svc_xprt *xprt; int len; - dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid)); /* * Get the server socket associated with this callback xprt */