SUNRPC: Capture value of xdr_buf::page_base

This value is usually zero, but will be non-zero more often in the
future. Knowing its value can be important diagnostic information.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

include/trace/events/sunrpc.h

@@ -62,6 +62,7 @@ DECLARE_EVENT_CLASS(rpc_xdr_buf_class,
 		__field(size_t, head_len)
 		__field(const void *, tail_base)
 		__field(size_t, tail_len)
+		__field(unsigned int, page_base)
 		__field(unsigned int, page_len)
 		__field(unsigned int, msg_len)
 	),
@@ -74,14 +75,17 @@ DECLARE_EVENT_CLASS(rpc_xdr_buf_class,
 		__entry->head_len = xdr->head[0].iov_len;
 		__entry->tail_base = xdr->tail[0].iov_base;
 		__entry->tail_len = xdr->tail[0].iov_len;
+		__entry->page_base = xdr->page_base;
 		__entry->page_len = xdr->page_len;
 		__entry->msg_len = xdr->len;
 	),
 
-	TP_printk("task:%u@%u head=[%p,%zu] page=%u tail=[%p,%zu] len=%u",
+	TP_printk("task:%u@%u head=[%p,%zu] page=%u(%u) tail=[%p,%zu] len=%u",
 		__entry->task_id, __entry->client_id,
-		__entry->head_base, __entry->head_len, __entry->page_len,
-		__entry->tail_base, __entry->tail_len, __entry->msg_len
+		__entry->head_base, __entry->head_len,
+		__entry->page_len, __entry->page_base,
+		__entry->tail_base, __entry->tail_len,
+		__entry->msg_len
 	)
 );
 
@@ -1496,6 +1500,7 @@ DECLARE_EVENT_CLASS(svc_xdr_buf_class,
 		__field(size_t, head_len)
 		__field(const void *, tail_base)
 		__field(size_t, tail_len)
+		__field(unsigned int, page_base)
 		__field(unsigned int, page_len)
 		__field(unsigned int, msg_len)
 	),
@@ -1506,14 +1511,17 @@ DECLARE_EVENT_CLASS(svc_xdr_buf_class,
 		__entry->head_len = xdr->head[0].iov_len;
 		__entry->tail_base = xdr->tail[0].iov_base;
 		__entry->tail_len = xdr->tail[0].iov_len;
+		__entry->page_base = xdr->page_base;
 		__entry->page_len = xdr->page_len;
 		__entry->msg_len = xdr->len;
 	),
 
-	TP_printk("xid=0x%08x head=[%p,%zu] page=%u tail=[%p,%zu] len=%u",
+	TP_printk("xid=0x%08x head=[%p,%zu] page=%u(%u) tail=[%p,%zu] len=%u",
 		__entry->xid,
-		__entry->head_base, __entry->head_len, __entry->page_len,
-		__entry->tail_base, __entry->tail_len, __entry->msg_len
+		__entry->head_base, __entry->head_len,
+		__entry->page_len, __entry->page_base,
+		__entry->tail_base, __entry->tail_len,
+		__entry->msg_len
 	)
 );