[PATCH v1 02/22] SUNRPC: Hoist trace_xprtrdma_op_allocate into generic code

Chuck Lever
2020-07-08T20:09:14Z

Introduce a tracepoint in call_allocate that reports the exact
sizes in the RPC buffer allocation request and the status of the
result. This helps catch problems with XDR buffer provisioning,
and replaces transport-specific debugging instrumentation.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
include/trace/events/rpcrdma.h | 30 ------------------------------
include/trace/events/sunrpc.h | 30 ++++++++++++++++++++++++++++++
net/sunrpc/clnt.c | 3 +--
net/sunrpc/sched.c | 2 --
net/sunrpc/xprtrdma/transport.c | 2 --
5 files changed, 31 insertions(+), 36 deletions(-)

diff --git a/include/trace/events/rpcrdma.h b/include/trace/events/rpcrdma.h
index 0f05a6e2b9cb..920621536731 100644
--- a/include/trace/events/rpcrdma.h
+++ b/include/trace/events/rpcrdma.h
@@ -1150,36 +1150,6 @@ TRACE_EVENT(xprtrdma_decode_seg,
** Allocation/release of rpcrdma_reqs and rpcrdma_reps
**/

-TRACE_EVENT(xprtrdma_op_allocate,
- TP_PROTO(
- const struct rpc_task *task,
- const struct rpcrdma_req *req
- ),
-
- TP_ARGS(task, req),
-
- TP_STRUCT__entry(
- __field(unsigned int, task_id)
- __field(unsigned int, client_id)
- __field(const void *, req)
- __field(size_t, callsize)
- __field(size_t, rcvsize)
- ),
-
- TP_fast_assign(
- __entry->task_id = task->tk_pid;
- __entry->client_id = task->tk_client->cl_clid;
- __entry->req = req;
- __entry->callsize = task->tk_rqstp->rq_callsize;
- __entry->rcvsize = task->tk_rqstp->rq_rcvsize;
- ),
-
- TP_printk("task:%u@%u req=%p (%zu, %zu)",
- __entry->task_id, __entry->client_id,
- __entry->req, __entry->callsize, __entry->rcvsize
- )
-);
-
TRACE_EVENT(xprtrdma_op_free,
TP_PROTO(
const struct rpc_task *task,
diff --git a/include/trace/events/sunrpc.h b/include/trace/events/sunrpc.h
index 2a43ed40b7e3..ea61628b9deb 100644
--- a/include/trace/events/sunrpc.h
+++ b/include/trace/events/sunrpc.h
@@ -517,6 +517,36 @@ DEFINE_RPC_REPLY_EVENT(stale_creds);
DEFINE_RPC_REPLY_EVENT(bad_creds);
DEFINE_RPC_REPLY_EVENT(auth_tooweak);

+TRACE_EVENT(rpc_buf_alloc,
+ TP_PROTO(
+ const struct rpc_task *task,
+ int status
+ ),
+
+ TP_ARGS(task, status),
+
+ TP_STRUCT__entry(
+ __field(unsigned int, task_id)
+ __field(unsigned int, client_id)
+ __field(size_t, callsize)
+ __field(size_t, recvsize)
+ __field(int, status)
+ ),
+
+ TP_fast_assign(
+ __entry->task_id = task->tk_pid;
+ __entry->client_id = task->tk_client->cl_clid;
+ __entry->callsize = task->tk_rqstp->rq_callsize;
+ __entry->recvsize = task->tk_rqstp->rq_rcvsize;
+ __entry->status = status;
+ ),
+
+ TP_printk("task:%u@%u callsize=%zu recvsize=%zu status=%d",
+ __entry->task_id, __entry->client_id,
+ __entry->callsize, __entry->recvsize, __entry->status
+ )
+);
+
TRACE_EVENT(rpc_call_rpcerror,
TP_PROTO(
const struct rpc_task *task,
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index a91d1cdad9d7..2086f4389996 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1823,6 +1823,7 @@ call_allocate(struct rpc_task *task)
req->rq_rcvsize <<= 2;

status = xprt->ops->buf_alloc(task);
+ trace_rpc_buf_alloc(task, status);
xprt_inject_disconnect(xprt);
if (status == 0)
return;
@@ -1831,8 +1832,6 @@ call_allocate(struct rpc_task *task)
return;
}

- dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
-
if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
task->tk_action = call_allocate;
rpc_delay(task, HZ>>4);
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index 7eba20a88438..adce1e2ed10d 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -1036,8 +1036,6 @@ int rpc_malloc(struct rpc_task *task)
return -ENOMEM;

buf->len = size;
- dprintk("RPC: %5u allocated buffer of size %zu at %p\n",
- task->tk_pid, size, buf);
rqst->rq_buffer = buf->data;
rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize;
return 0;
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index 053c8ab1265a..612b60f31302 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -586,11 +586,9 @@ xprt_rdma_allocate(struct rpc_task *task)

rqst->rq_buffer = rdmab_data(req->rl_sendbuf);
rqst->rq_rbuffer = rdmab_data(req->rl_recvbuf);
- trace_xprtrdma_op_allocate(task, req);
return 0;

out_fail:
- trace_xprtrdma_op_allocate(task, NULL);
return -ENOMEM;
}