FEXCore: Allows disabling telemetry at runtime

This is useful for InstCountCI so you can disable the telemetry
gathering even if enabled so it doesn't affect the CI system.

.github/workflows/instcountci.yml

@@ -64,11 +64,13 @@ jobs:
       # Note the current convention is to use the -S and -B options here to specify source
       # and build directories, but this is only available with CMake 3.13 and higher.
       # The CMake binaries on the Github Actions machines are (as of this writing) 3.12
-      run: cmake $GITHUB_WORKSPACE -DENABLE_OFFLINE_TELEMETRY=False -DCMAKE_BUILD_TYPE=$BUILD_TYPE -G Ninja -DENABLE_VIXL_SIMULATOR=False -DENABLE_VIXL_DISASSEMBLER=True -DENABLE_LTO=False -DENABLE_ASSERTIONS=True
+      run: cmake $GITHUB_WORKSPACE -DCMAKE_BUILD_TYPE=$BUILD_TYPE -G Ninja -DENABLE_VIXL_SIMULATOR=False -DENABLE_VIXL_DISASSEMBLER=True -DENABLE_LTO=False -DENABLE_ASSERTIONS=True
 
     - name: Build
       working-directory: ${{runner.workspace}}/build
       shell: bash
+      env:
+        FEX_DISABLETELEMETRY: 1
       # Execute the build.  You can specify a specific target with "--target <NAME>"
       run: cmake --build . --config $BUILD_TYPE --target CodeSizeValidation instcountci_test_files
 

FEXCore/Source/Interface/Config/Config.json.in

@@ -329,6 +329,14 @@
           "Allows overriding the SVE width in the vixl simulator.",
           "Useful as a debugging feature."
         ]
+      },
+      "DisableTelemetry": {
+        "Type": "bool",
+        "Default": "false",
+        "Desc": [
+          "Disables telemetry at runtime.",
+          "Useful for CI instcountCI mostly"
+        ]
       }
     },
     "Logging": {

FEXCore/Source/Interface/Context/Context.h

@@ -238,6 +238,7 @@ namespace FEXCore::Context {
       FEX_CONFIG_OPT(ParanoidTSO, PARANOIDTSO);
       FEX_CONFIG_OPT(CacheObjectCodeCompilation, CACHEOBJECTCODECOMPILATION);
       FEX_CONFIG_OPT(x87ReducedPrecision, X87REDUCEDPRECISION);
+      FEX_CONFIG_OPT(DisableTelemetry, DISABLETELEMETRY);
     } Config;
 
     FEXCore::HostFeatures HostFeatures;

FEXCore/Source/Interface/Core/OpcodeDispatcher.cpp

@@ -4858,6 +4858,11 @@ void OpDispatchBuilder::CheckLegacySegmentRead(OrderedNode *NewNode, uint32_t Se
     return;
   }
 
+  if (CTX->Config.DisableTelemetry()) {
+    // Telemetry disabled at runtime.
+    return;
+  }
+
   FEXCore::Telemetry::TelemetryType TelemIndex{};
   switch (SegmentReg) {
     case FEXCore::X86Tables::DecodeFlags::FLAG_ES_PREFIX:
@@ -4892,6 +4897,11 @@ void OpDispatchBuilder::CheckLegacySegmentWrite(OrderedNode *NewNode, uint32_t S
     return;
   }
 
+  if (CTX->Config.DisableTelemetry()) {
+    // Telemetry disabled at runtime.
+    return;
+  }
+
   FEXCore::Telemetry::TelemetryType TelemIndex{};
   switch (SegmentReg) {
     case FEXCore::X86Tables::DecodeFlags::FLAG_ES_PREFIX:

FEXCore/Source/Utils/Telemetry.cpp

@@ -33,7 +33,15 @@ namespace FEXCore::Telemetry {
     "Uses 32-bit Segment CS",
     "Uses 32-bit Segment DS",
   };
+
+  static bool Enabled {true};
   void Initialize() {
+    FEX_CONFIG_OPT(DisableTelemetry, DISABLETELEMETRY);
+    if (DisableTelemetry) {
+      Enabled = false;
+      return;
+    }
+
     auto DataDirectory = Config::GetDataDirectory();
     DataDirectory += "Telemetry/";
 
@@ -45,6 +53,10 @@ namespace FEXCore::Telemetry {
   }
 
   void Shutdown(fextl::string const &ApplicationName) {
+    if (!Enabled) {
+      return;
+    }
+
     auto DataDirectory = Config::GetDataDirectory();
     DataDirectory += "Telemetry/" + ApplicationName + ".telem";
 

FEXCore/include/FEXCore/Core/CoreState.h

@@ -239,9 +239,7 @@ namespace FEXCore::Core {
       uint64_t FallbackHandlerPointers[FallbackHandlerIndex::OPINDEX_MAX];
       uint64_t NamedVectorConstantPointers[FEXCore::IR::NamedVectorConstant::NAMED_VECTOR_MAX];
       uint64_t IndexedNamedVectorConstantPointers[FEXCore::IR::IndexNamedVectorConstant::INDEXED_NAMED_VECTOR_MAX];
-#ifndef FEX_DISABLE_TELEMETRY
       uint64_t TelemetryValueAddresses[FEXCore::Telemetry::TYPE_LAST];
-#endif
 
       // Thread Specific
       /**

FEXCore/include/FEXCore/Utils/Telemetry.h

@@ -9,25 +9,6 @@
 #include <filesystem>
 
 namespace FEXCore::Telemetry {
-#ifndef FEX_DISABLE_TELEMETRY
-  class Value;
-
-  class Value final {
-    public:
-      Value() = default;
-      Value(uint64_t Default) : Data {Default} {}
-
-      uint64_t operator*() const { return Data; }
-      void operator=(uint64_t Value) { Data = Value; }
-      void operator|=(uint64_t Value) { Data |= Value; }
-      void operator++(int) { Data++; }
-
-      std::atomic<uint64_t> *GetAddr() { return &Data; }
-
-    private:
-      std::atomic<uint64_t> Data;
-  };
-
   enum TelemetryType {
     TYPE_HAS_SPLIT_LOCKS,
     TYPE_16BYTE_SPLIT,
@@ -51,6 +32,25 @@ namespace FEXCore::Telemetry {
     TYPE_LAST,
   };
 
+#ifndef FEX_DISABLE_TELEMETRY
+  class Value;
+
+  class Value final {
+    public:
+      Value() = default;
+      Value(uint64_t Default) : Data {Default} {}
+
+      uint64_t operator*() const { return Data; }
+      void operator=(uint64_t Value) { Data = Value; }
+      void operator|=(uint64_t Value) { Data |= Value; }
+      void operator++(int) { Data++; }
+
+      std::atomic<uint64_t> *GetAddr() { return &Data; }
+
+    private:
+      std::atomic<uint64_t> Data;
+  };
+
   FEX_DEFAULT_VISIBILITY Value &GetTelemetryValue(TelemetryType Type);
 
   FEX_DEFAULT_VISIBILITY void Initialize();

Source/Tools/CodeSizeValidation/Main.cpp

@@ -377,6 +377,8 @@ int main(int argc, char **argv, char **const envp) {
   FEXCore::Config::EraseSet(FEXCore::Config::CONFIG_DISASSEMBLE, fextl::fmt::format("{}", static_cast<uint64_t>(FEXCore::Config::Disassemble::BLOCKS | FEXCore::Config::Disassemble::STATS)));
   // Choose bitness.
   FEXCore::Config::EraseSet(FEXCore::Config::CONFIG_IS64BIT_MODE, TestHeaderData->Bitness == 64 ? "1" : "0");
+  // Disable telemetry, it can affect instruction counts.
+  FEXCore::Config::EraseSet(FEXCore::Config::CONFIG_DISABLETELEMETRY, "1");
 
   // Host feature override. Only supports overriding SVE width.
   enum HostFeatures {