->buf_free is called nearly once per RPC. Only rarely does
xprt_rdma_free() have to do anything, thus tracing every one of
these calls seems unnecessary. Instead, just throw a trace event
when that one occasional RPC still has MRs that need to be
released.
xprt_rdma_free() is further micro-optimized to reduce the amount of
work done in the common case.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
include/trace/events/rpcrdma.h | 22 ++++++++++++++++++++++
net/sunrpc/xprtrdma/transport.c | 7 ++++---
2 files changed, 26 insertions(+), 3 deletions(-)
diff --git a/include/trace/events/rpcrdma.h b/include/trace/events/rpcrdma.h
index 166bbeef996c..69e1caf7e882 100644
--- a/include/trace/events/rpcrdma.h
+++ b/include/trace/events/rpcrdma.h
@@ -1167,6 +1167,28 @@ TRACE_EVENT(xprtrdma_decode_seg,
)
);
+TRACE_EVENT(xprtrdma_mrs_zap,
+ TP_PROTO(
+ const struct rpc_task *task
+ ),
+
+ TP_ARGS(task),
+
+ TP_STRUCT__entry(
+ __field(unsigned int, task_id)
+ __field(unsigned int, client_id)
+ ),
+
+ TP_fast_assign(
+ __entry->task_id = task->tk_pid;
+ __entry->client_id = task->tk_client->cl_clid;
+ ),
+
+ TP_printk("task:%u@%u",
+ __entry->task_id, __entry->client_id
+ )
+);
+
/**
** Callback events
**/
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index 8915e42240d3..bb3ed3db6c0a 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -599,11 +599,12 @@ static void
xprt_rdma_free(struct rpc_task *task)
{
struct rpc_rqst *rqst = task->tk_rqstp;
- struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
- if (!list_empty(&req->rl_registered))
- frwr_unmap_sync(r_xprt, req);
+ if (unlikely(!list_empty(&req->rl_registered))) {
+ trace_xprtrdma_mrs_zap(task);
+ frwr_unmap_sync(rpcx_to_rdmax(rqst->rq_xprt), req);
+ }
/* XXX: If the RPC is completing because of a signal and
* not because a reply was received, we ought to ensure
