cpu: add comments and change input type to list

Change inst_threshold param to inst_thresholds, which it is now
expecting a list of thresholds instead of one threshold.

Add more getter and setter functions:

addThreshold:
it is for adding new thresholds

getCounter:
it is for getting the current counter

getThresholds:
it returns the list of targeted thresholds

resetThresholds:
it clears all the targeted thresholds

Change-Id: I48d022effe7b315112ac150e6a4eaf5aab41c514

configs/example/gem5_library/x86-global-inst-tracker.py

@@ -76,14 +76,16 @@ cache_hierarchy = PrivateL1CacheHierarchy(
 
 memory = SingleChannelDDR4_2400("1GB")
 
+# using 9 cores because when using openmp in SE mode, the number of cores
+# should be # cores + 1
 processor = SimpleProcessor(cpu_type=CPUTypes.TIMING, num_cores=9, isa=ISA.X86)
 
 # setup instruction tracker
 
 # first, we need to create a global instruction tracker
 global_inst_tracker = GlobalInstTracker(
-    # threshold to trigger the event
-    inst_threshold=100_000_000
+    # a list of thresholds to trigger the event
+    inst_thresholds=[100_000_000, 100_020_000]
 )
 
 # then, we create a local instruction tracker for each core
@@ -123,14 +125,17 @@ def max_inst_handler():
     # when it reached this function, it means that it successfully raised
     # the ExitEvent.MAX_INSTS event
     print("Reached MAX_INSTS with 100000000 instructions")
-    print("Changing threshold to 20000")
-    # we can change the threshold of the global instruction tracker
-    global_inst_tracker.changeThreshold(20000)
-    # we need to reset the counter of the global instruction tracker
-    # the counter does not reset automatically
+    yield False
+    print("Reached MAX_INSTS with 100020000 instructions")
+    # we can get the current counter of the global instruction tracker
+    print(f"Current counter: {global_inst_tracker.getCounter()}")
+    # we can reset the counter
     global_inst_tracker.resetCounter()
-    m5.stats.dump()
-    m5.stats.reset()
+    print(f"After reset, current counter: {global_inst_tracker.getCounter()}")
+    # we can add new threshold to the global instruction tracker
+    global_inst_tracker.addThreshold(20000)
+    # we can get the thresholds
+    print(f"Current thresholds: {global_inst_tracker.getThresholds()}")
     yield False
     print("Reached MAX_INSTS with 20000 instructions")
     print("Stop listening to instructions")
@@ -141,9 +146,7 @@ def max_inst_handler():
     #
     # for tracker in all_trackers:
     #     tracker.startListening()
-    m5.stats.dump()
-    m5.stats.reset()
-    yield False
+    yield True
 
 
 simulator = Simulator(

src/cpu/probes/InstTracker.py

@@ -41,13 +41,15 @@ class GlobalInstTracker(SimObject):
     cxx_class = "gem5::GlobalInstTracker"
 
     cxx_exports = [
-        PyBindMethod("changeThreshold"),
+        PyBindMethod("addThreshold"),
+        PyBindMethod("getCounter"),
         PyBindMethod("resetCounter"),
-        PyBindMethod("getThreshold"),
+        PyBindMethod("getThresholds"),
+        PyBindMethod("resetThresholds"),
     ]
 
-    inst_threshold = Param.Counter(
-        "The instruction threshold to trigger an" " exit event"
+    inst_thresholds = VectorParam.Counter(
+        "A list of instruction thresholds to trigger an exit event"
     )
 
 

src/cpu/probes/inst_tracker.cc

@@ -81,22 +81,26 @@ LocalInstTracker::stopListening()
 
 GlobalInstTracker::GlobalInstTracker(const GlobalInstTrackerParams &params)
     : SimObject(params),
-      instCount(0),
-      instThreshold(params.inst_threshold)
+      instCount(0)
 {
-    DPRINTF(InstTracker, "instThreshold = %lu\n", instThreshold);
+    for (const auto &threshold : params.inst_thresholds) {
+        instThresholdSet.insert(threshold);
+        DPRINTF(InstTracker, "adding the instruction threshold\n"
+                              "instThreshold = %lu\n", threshold);
+    }
+    DPRINTF(InstTracker, "instThresholdSet size = %lu\n",
+            instThresholdSet.size());
 }
 
 void
 GlobalInstTracker::updateAndCheckInstCount(const uint64_t& inst)
 {
     instCount ++;
-    if (instCount >= instThreshold) {
+    if (instThresholdSet.find(instCount) != instThresholdSet.end()) {
         DPRINTF(InstTracker, "Instruction count reached the threshold\n"
-                                "instCount = %lu\n"
-                                "instThreshold = %lu\n",
-                                instCount, instThreshold);
-
+                                "instCount = %lu\n",
+                                instCount);
+        instThresholdSet.erase(instCount);
         // note that when the threshold is reached, the simulation will raise
         // and exit event but it will not reset the instruction counter.
         // user can reset the counter by calling the resetCounter() function

src/cpu/probes/inst_tracker.hh

@@ -29,6 +29,8 @@
 #ifndef __CPU_PROBES_INST_TRACKER_HH__
 #define __CPU_PROBES_INST_TRACKER_HH__
 
+#include <unordered_set>
+
 #include "debug/InstTracker.hh"
 #include "params/GlobalInstTracker.hh"
 #include "params/LocalInstTracker.hh"
@@ -101,18 +103,24 @@ class GlobalInstTracker : public SimObject
     uint64_t instCount;
 
     /**
-      * the threshold for the number of instructions that should be executed
-      * before the simulation exits
+      * a set of thresholds for the number of instructions that should be
+      * executed before the simulation exits
      */
-    uint64_t instThreshold;
+    std::unordered_set<uint64_t> instThresholdSet;
 
   public:
     void
-    changeThreshold(uint64_t new_threshold)
+    addThreshold(uint64_t new_threshold)
     {
-        instThreshold = new_threshold;
-        DPRINTF(InstTracker, "Changing the instruction threshold\n"
-                                  "instThreshold = %lu\n", instThreshold);
+        instThresholdSet.insert(new_threshold);
+        DPRINTF(InstTracker, "adding the instruction threshold %lu\n",
+                                                              new_threshold);
+    };
+
+    uint64_t
+    getCounter() const
+    {
+        return instCount;
     };
 
     void
@@ -123,10 +131,17 @@ class GlobalInstTracker : public SimObject
                                               "instCount = %lu\n", instCount);
     };
 
-    uint64_t
-    getThreshold() const
+    std::unordered_set<uint64_t>
+    getThresholds() const
     {
-        return instThreshold;
+        return instThresholdSet;
+    };
+
+    void
+    resetThresholds()
+    {
+        instThresholdSet.clear();
+        DPRINTF(InstTracker, "Resetting the instruction thresholds\n");
     };
 };