SUNRPC: Capture completion of all RPC tasks

RPC tasks on the backchannel never invoke xprt_complete_rqst(), so
there is no way to report their tk_status at completion. Also, any
RPC task that exits via rpc_exit_task() before it is replied to will
also disappear without a trace.

Introduce a trace point that is symmetrical with rpc_task_begin that
captures the termination status of each RPC task.

Sample trace output for callback requests initiated on the server:
   kworker/u8:12-448   [003]   127.025240: rpc_task_end:         task:50@3 flags=ASYNC|DYNAMIC|SOFT|SOFTCONN|SENT runstate=RUNNING|ACTIVE status=0 action=rpc_exit_task
   kworker/u8:12-448   [002]   127.567310: rpc_task_end:         task:51@3 flags=ASYNC|DYNAMIC|SOFT|SOFTCONN|SENT runstate=RUNNING|ACTIVE status=0 action=rpc_exit_task
   kworker/u8:12-448   [001]   130.506817: rpc_task_end:         task:52@3 flags=ASYNC|DYNAMIC|SOFT|SOFTCONN|SENT runstate=RUNNING|ACTIVE status=0 action=rpc_exit_task

Odd, though, that I never see trace_rpc_task_complete, either in the
forward or backchannel. Should it be removed?

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h
index 378233f..205bf28 100644 (file)
--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h
@@ -165,6 +165,7 @@ DECLARE_EVENT_CLASS(rpc_task_running,
 DEFINE_RPC_RUNNING_EVENT(begin);
 DEFINE_RPC_RUNNING_EVENT(run_action);
 DEFINE_RPC_RUNNING_EVENT(complete);
+DEFINE_RPC_RUNNING_EVENT(end);
 
 DECLARE_EVENT_CLASS(rpc_task_queued,
 

diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index 987c4b1..9c79548 100644 (file)
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -824,6 +824,7 @@ rpc_reset_task_statistics(struct rpc_task *task)
  */
 void rpc_exit_task(struct rpc_task *task)
 {
+       trace_rpc_task_end(task, task->tk_action);
        task->tk_action = NULL;
        if (task->tk_ops->rpc_count_stats)
                task->tk_ops->rpc_count_stats(task, task->tk_calldata);