mem: Auto-generate CommMonitor trace file names

Splits the CommMonitor trace_file parameter into three parameters. Previously,
the trace was only enabled if the trace_file parameter was set, and would be
written to this file. This patch adds in a trace_enable and trace_compress
parameter to the CommMonitor.

No trace is generated if trace_enable is set to False. If it is set to True, the
trace is written to a file based on the name of the SimObject in the simulation
hierarchy. For example, system.cluster.il1_commmonitor.trc. This filename can be
overridden by additionally specifying a file name to the trace_file parameter
(more on this later).

The trace_compress parameter will append .gz to any filename if set to True.
This enables compression of the generated traces. If the file name already ends
in .gz, then no changes are made.

The trace_file parameter will override the name set by the trace_enable
parameter. In the case that the specified name does not end in .gz but
trace_compress is set to true, .gz is appended to the supplied file name.

src/mem/CommMonitor.py

@@ -53,6 +53,13 @@ class CommMonitor(MemObject):
     master = MasterPort("Master port")
     slave = SlavePort("Slave port")
 
+    # Boolean to enable or disable the trace. Writes to an a file named based on
+    # SimObject hierarchy.
+    trace_enable = Param.Bool(False, "Enable trace capture")
+
+    # Boolean to compress the trace or not.
+    trace_compress = Param.Bool(True, "Enable trace compression")
+
     # packet trace output file, disabled by default
     trace_file = Param.String("", "Packet trace output file")
 

src/mem/comm_monitor.cc

@@ -58,11 +58,28 @@ CommMonitor::CommMonitor(Params* params)
       traceStream(NULL),
       system(params->system)
 {
-    // If we are using a trace file, then open the file,
-    if (params->trace_file != "") {
-        // If the trace file is not specified as an absolute path,
-        // append the current simulation output directory
-        std::string filename = simout.resolve(params->trace_file);
+    // If we are using a trace file, then open the file
+    if (params->trace_enable) {
+        std::string filename;
+        if (params->trace_file != "") {
+            // If the trace file is not specified as an absolute path,
+            // append the current simulation output directory
+            filename = simout.resolve(params->trace_file);
+
+            std::string suffix = ".gz";
+            // If trace_compress has been set, check the suffix. Append
+            // accordingly.
+            if (params->trace_compress &&
+                filename.compare(filename.size() - suffix.size(), suffix.size(),
+                                 suffix) != 0)
+                    filename = filename + suffix;
+        } else {
+            // Generate a filename from the name of the SimObject. Append .trc
+            // and .gz if we want compression enabled.
+            filename = simout.resolve(name() + ".trc" +
+                                      (params->trace_compress ? ".gz" : ""));
+        }
+
         traceStream = new ProtoOutputStream(filename);
 
         // Create a protobuf message for the header and write it to

tests/configs/tgen-simple-mem.py

@@ -55,7 +55,8 @@ system = System(cpu = cpu, physmem = SimpleMemory(),
                                             VoltageDomain()))
 
 # add a communication monitor, and also trace all the packets
-system.monitor = CommMonitor(trace_file = "monitor.ptrc.gz")
+system.monitor = CommMonitor(trace_file = "monitor.ptrc.gz",
+                             trace_enable = True)
 
 # connect the traffic generator to the bus via a communication monitor
 system.cpu.port = system.monitor.slave