SUNRPC: Add trace points to observe transport congestion control
To help debug problems with RPC/RDMA credit management, replace
dprintk() call sites in the transport send lock paths with trace
events.
Similar trace points are defined for the non-congestion paths.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 8a45b3c..fcbeb56 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -205,20 +205,20 @@ int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) {
if (task == xprt->snd_task)
- return 1;
+ goto out_locked;
goto out_sleep;
}
if (test_bit(XPRT_WRITE_SPACE, &xprt->state))
goto out_unlock;
xprt->snd_task = task;
+out_locked:
+ trace_xprt_reserve_xprt(xprt, task);
return 1;
out_unlock:
xprt_clear_locked(xprt);
out_sleep:
- dprintk("RPC: %5u failed to lock transport %p\n",
- task->tk_pid, xprt);
task->tk_status = -EAGAIN;
if (RPC_IS_SOFT(task))
rpc_sleep_on_timeout(&xprt->sending, task, NULL,
@@ -269,23 +269,22 @@ int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task)
if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) {
if (task == xprt->snd_task)
- return 1;
+ goto out_locked;
goto out_sleep;
}
if (req == NULL) {
xprt->snd_task = task;
- return 1;
+ goto out_locked;
}
if (test_bit(XPRT_WRITE_SPACE, &xprt->state))
goto out_unlock;
if (!xprt_need_congestion_window_wait(xprt)) {
xprt->snd_task = task;
- return 1;
+ goto out_locked;
}
out_unlock:
xprt_clear_locked(xprt);
out_sleep:
- dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt);
task->tk_status = -EAGAIN;
if (RPC_IS_SOFT(task))
rpc_sleep_on_timeout(&xprt->sending, task, NULL,
@@ -293,6 +292,9 @@ int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task)
else
rpc_sleep_on(&xprt->sending, task, NULL);
return 0;
+out_locked:
+ trace_xprt_reserve_cong(xprt, task);
+ return 1;
}
EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong);
@@ -357,6 +359,7 @@ void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
xprt_clear_locked(xprt);
__xprt_lock_write_next(xprt);
}
+ trace_xprt_release_xprt(xprt, task);
}
EXPORT_SYMBOL_GPL(xprt_release_xprt);
@@ -374,6 +377,7 @@ void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task)
xprt_clear_locked(xprt);
__xprt_lock_write_next_cong(xprt);
}
+ trace_xprt_release_cong(xprt, task);
}
EXPORT_SYMBOL_GPL(xprt_release_xprt_cong);
@@ -395,8 +399,7 @@ __xprt_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req)
{
if (req->rq_cong)
return 1;
- dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n",
- req->rq_task->tk_pid, xprt->cong, xprt->cwnd);
+ trace_xprt_get_cong(xprt, req->rq_task);
if (RPCXPRT_CONGESTED(xprt)) {
xprt_set_congestion_window_wait(xprt);
return 0;
@@ -418,6 +421,7 @@ __xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req)
req->rq_cong = 0;
xprt->cong -= RPC_CWNDSCALE;
xprt_test_and_clear_congestion_window_wait(xprt);
+ trace_xprt_put_cong(xprt, req->rq_task);
__xprt_lock_write_next_cong(xprt);
}