Do not pass garbage values to perf_event_open (#98)

* Do not pass garbage values to perf_event_open
* Use an array with a pre-defined size for regs

Author: soramichi

pcm-core.cpp

@@ -63,7 +63,7 @@ extern "C" {
 	SystemCounterState SysBeforeState, SysAfterState;
 	std::vector<CoreCounterState> BeforeState, AfterState;
 	std::vector<SocketCounterState> DummySocketStates;
-	EventSelectRegister regs[4];
+	EventSelectRegister regs[PERF_MAX_COUNTERS];
 	PCM::ExtendedCustomCoreEventDescription conf;
 
 	int pcm_c_build_core_event(uint8_t idx, const char * argv)
@@ -290,16 +290,12 @@ int main(int argc, char * argv[])
 	int calibrated = PCM_CALIBRATION_INTERVAL - 2; // keeps track is the clock calibration needed
 	unsigned int numberOfIterations = 0; // number of iterations
 	string program = string(argv[0]);
-	EventSelectRegister regs[4];
+	EventSelectRegister regs[PERF_MAX_COUNTERS];
 	PCM::ExtendedCustomCoreEventDescription conf;
 	bool show_partial_core_output = false;
 	std::bitset<MAX_CORES> ycores;
 
-	// Occasionally the memory is not properly nulled because counters appear to
-	// be programmed even without given arguments so making really sure
-	memset( &regs, 0, sizeof(regs) );
-
-    PCM * m = PCM::getInstance();
+        PCM * m = PCM::getInstance();
 
 	conf.fixedCfg = NULL; // default
 	conf.nGPCounters = m->getMaxCustomCoreEvents();

types.h

@@ -50,7 +50,9 @@ typedef signed int int32;
 #define IA32_PERFEVTSEL2_ADDR           (IA32_PERFEVTSEL0_ADDR + 2)
 #define IA32_PERFEVTSEL3_ADDR           (IA32_PERFEVTSEL0_ADDR + 3)
 
-#define PERF_MAX_COUNTERS               (11)
+#define PERF_MAX_FIXED_COUNTERS          (3)
+#define PERF_MAX_CUSTOM_COUNTERS         (8)
+#define PERF_MAX_COUNTERS               (PERF_MAX_FIXED_COUNTERS + PERF_MAX_CUSTOM_COUNTERS)
 
 #define IA32_DEBUGCTL                   (0x1D9)
 
@@ -319,6 +321,8 @@ struct EventSelectRegister
         } fields;
         uint64 value;
     };
+
+    EventSelectRegister() : value(0) {}
 };