Added customized block layer trace points for analyzing I/O

schedulers.

instrumentation/events/lttng-module/block.h

@@ -683,6 +683,39 @@ LTTNG_TRACEPOINT_EVENT(block_bio_complete,
 	)
 )
 
+/**
+ * block_bio_complete2 - completed all work on the block operation, also listing
+ *                       pid of thread that signals the completion
+ * @q: queue holding the block operation
+ * @bio: block operation completed
+ * @error: io error value
+ * @ts: task struct of calling thread
+ *
+ * This tracepoint indicates there is no further work to do on this
+ * block IO operation @bio.
+ *
+ * Compability to kernel versions other than 4.15 is omitted.
+ */
+LTTNG_TRACEPOINT_EVENT(block_bio_complete2,
+        TP_PROTO(struct request_queue *q, struct bio *bio, int error,
+                 struct task_struct *ts),
+
+        TP_ARGS(q, bio, error, ts),
+
+        TP_FIELDS(
+                ctf_integer(dev_t, dev, bio_dev(bio))
+                ctf_integer(sector_t, sector, bio->bi_iter.bi_sector)
+                ctf_integer(unsigned int, nr_sector, bio_sectors(bio))
+                ctf_integer(int, error, error)
+                blk_rwbs_ctf_integer(unsigned int, rwbs,
+                        lttng_bio_op(bio), lttng_bio_rw(bio),
+                        bio->bi_iter.bi_size)
+                ctf_integer(pid_t, reqtid, ts->pid)
+                ctf_array_text(char, comm, ts->comm, TASK_COMM_LEN)
+                ctf_integer_hex(unsigned long, bptr, (unsigned long) bio)
+        )
+)
+
 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,9,0))
 LTTNG_TRACEPOINT_EVENT_CLASS(block_bio_merge,
 
@@ -778,6 +811,67 @@ LTTNG_TRACEPOINT_EVENT(block_bio_queue,
 		ctf_array_text(char, comm, current->comm, TASK_COMM_LEN)
 	)
 )
+
+/**
+ * block_rq_issue2 - dispatch request to the device driver listing bio and
+ *                   "offending" pid
+ * @q: queue holding operation
+ * @bio: new block operation
+ * @ts: task struct that caused queueing
+ *
+ * About to place the block IO operation @bio into @q.
+ * Since this is only for kernel 4.15.0, I will omit backwards compability!
+ */
+LTTNG_TRACEPOINT_EVENT(block_rq_issue2,
+
+	TP_PROTO(struct request_queue *q, struct request *rq, 
+             struct task_struct *ts),
+
+	TP_ARGS(q, rq, ts),
+
+	TP_FIELDS(
+		ctf_integer(dev_t, dev,
+			rq->rq_disk ? disk_devt(rq->rq_disk) : 0)
+		ctf_integer(sector_t, sector, blk_rq_trace_sector(rq))
+		ctf_integer(unsigned int, nr_sector, blk_rq_trace_nr_sectors(rq))
+		ctf_integer(unsigned int, bytes, blk_rq_bytes(rq))
+		ctf_integer(pid_t, tid, current->pid)
+		blk_rwbs_ctf_integer(unsigned int, rwbs,
+			lttng_req_op(rq), lttng_req_rw(rq), blk_rq_bytes(rq))
+        ctf_integer(pid_t, reqtid, ts->pid)                                   
+		ctf_array_text(char, comm, current->comm, TASK_COMM_LEN)
+        ctf_integer_hex(unsigned long, bptr, (unsigned long) rq->bio)
+        ctf_integer(unsigned int, nr_hwq, q->nr_hw_queues)
+	)
+)
+
+/**
+ * block_bio_queue2 - putting new block IO operation in queue and listing
+ *                    current process id
+ * @q: queue holding operation
+ * @bio: new block operation
+ * @ts: task struct that caused queueing
+ *
+ * About to place the block IO operation @bio into @q.
+ * Since this is only for kernel 4.15.0, I will omit backwards compability!
+ */
+LTTNG_TRACEPOINT_EVENT(block_bio_queue2,                                         
+
+    TP_PROTO(struct request_queue *q, struct bio *bio, struct task_struct *ts),                         
+
+    TP_ARGS(q, bio, ts),                                                            
+
+    TP_FIELDS(                                                                  
+        ctf_integer(dev_t, dev, bio_dev(bio))                                   
+        ctf_integer(sector_t, sector, bio->bi_iter.bi_sector)                   
+        ctf_integer(unsigned int, nr_sector, bio_sectors(bio))                  
+        blk_rwbs_ctf_integer(unsigned int, rwbs,                                
+            lttng_bio_op(bio), lttng_bio_rw(bio), bio->bi_iter.bi_size)   
+        ctf_integer(pid_t, reqtid, ts->pid)                                   
+        ctf_array_text(char, comm, current->comm, TASK_COMM_LEN)
+        ctf_integer_hex(unsigned long, bptr, (unsigned long) bio)               
+    )                                                                           
+)   
 #else /* if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,9,0)) */
 LTTNG_TRACEPOINT_EVENT_CLASS(block_bio,