More DBUG_PRINT's to make it easier to debug

parallel replication

storage/innobase/handler/ha_innodb.cc

@@ -4257,6 +4257,7 @@ innobase_commit(
 	trx_t*		trx;
 
 	DBUG_ENTER("innobase_commit");
+	DBUG_PRINT("enter", ("commit_trx: %d", commit_trx));
 	DBUG_ASSERT(hton == innodb_hton_ptr);
 	DBUG_PRINT("trans", ("ending transaction"));
 

storage/innobase/log/log0log.cc

@@ -1268,6 +1268,10 @@ log_group_file_header_flush(
 	}
 #endif /* UNIV_DEBUG */
 	if (log_do_write) {
+ 	       DBUG_PRINT("ib_log", ("write " LSN_PF
+                                     " group " ULINTPF
+                                     " file " ULINTPF " header",
+                                     start_lsn, group->id, nth_file));
 		log_sys->n_log_ios++;
 
 		MONITOR_INC(MONITOR_LOG_IO);
@@ -1539,6 +1543,9 @@ log_write_up_to(
 		return;
 	}
 
+	DBUG_PRINT("ib_log", ("write " LSN_PF " to " LSN_PF,
+			      log_sys->written_to_all_lsn,
+			      log_sys->lsn));
 #ifdef UNIV_DEBUG
 	if (log_debug_writes) {
 		fprintf(stderr,

storage/innobase/trx/trx0trx.cc

@@ -1138,6 +1138,7 @@ trx_flush_log_if_needed_low(
 	lsn_t	lsn)	/*!< in: lsn up to which logs are to be
 			flushed. */
 {
+       DBUG_ENTER("trx_flush_log_if_needed_low");
 	switch (srv_flush_log_at_trx_commit) {
 	case 0:
 		/* Do nothing */
@@ -1156,6 +1157,7 @@ trx_flush_log_if_needed_low(
 	default:
 		ut_error;
 	}
+        DBUG_VOID_RETURN;
 }
 
 /**********************************************************************//**
@@ -1690,15 +1692,17 @@ trx_commit_complete_for_mysql(
 	trx_t*	trx)	/*!< in/out: transaction */
 {
 	ut_a(trx);
+        DBUG_ENTER("trx_commit_complete_for_mysql");
 
 	if (!trx->must_flush_log_later
 	    || (srv_flush_log_at_trx_commit == 1 && trx->active_commit_ordered)) {
-		return;
+		DBUG_VOID_RETURN;
 	}
 
 	trx_flush_log_if_needed(trx->commit_lsn, trx);
 
 	trx->must_flush_log_later = FALSE;
+	DBUG_VOID_RETURN;
 }
 
 /**********************************************************************//**