[XRay] [test-suite] Add FDR mode microbenchmark

[eizan]

Summary

Move retref-bench sources and support files into new subdir
Add XRay FDR mode microbenchmark

[eizan]

• cleanup unused commented-out code

[dberris]

MicroBenchmarks/XRay/FDRMode/CMakeLists.txt

11

Not sure if all systems will be happy with a colon in the filename of the test... can we use a less extraordinary character here? Say another - or _ instead?

MicroBenchmarks/XRay/FDRMode/fdrmode-bench.cc

2

Please put the same license (LLVM license) in the header of this file. Use similar language to the one we put on the ReturnReference benchmarks.

[eizan]

• Add header with license and description to fdrmode-bench.cc
• rename .test files to use less exotic character set

[dberris]

LGTM

MicroBenchmarks/XRay/CMakeLists.txt

-check_cxx_compiler_flag(-fxray-instrument COMPILER_HAS_FXRAY_INSTRUMENT)
-if(ARCH STREQUAL "x86" AND COMPILER_HAS_FXRAY_INSTRUMENT)
-  file(COPY lit.local.cfg DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-
-  list(APPEND CPPFLAGS -std=c++11 -Wl,--gc-sections -fxray-instrument)
-  list(APPEND LDFLAGS -fxray-instrument)
-  llvm_test_run(--benchmark_filter=dummy_skip_ignore)
-  llvm_test_executable(retref-bench retref-bench.cc)
-  target_link_libraries(retref-bench benchmark)
-
-  file(COPY retref-bench_BM_ReturnNeverInstrumented.test
-       DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-  file(COPY retref-bench_BM_ReturnInstrumentedUnPatched.test
-       DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-  file(COPY retref-bench_BM_ReturnInstrumentedPatchedThenUnpatched.test
-       DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-  file(COPY retref-bench_BM_ReturnInstrumentedPatched.test
-       DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-  file(COPY retref-bench_BM_RDTSCP_Cost.test
-       DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-  file(COPY retref-bench_BM_ReturnInstrumentedPatchedWithLogHandler.test
-       DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-endif()
+add_subdirectory(ReturnReference)
+add_subdirectory(FDRMode)

MicroBenchmarks/XRay/FDRMode/CMakeLists.txt

 check_cxx_compiler_flag(-fxray-instrument COMPILER_HAS_FXRAY_INSTRUMENT)
 if(ARCH STREQUAL "x86" AND COMPILER_HAS_FXRAY_INSTRUMENT)
   file(COPY lit.local.cfg DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
 
   list(APPEND CPPFLAGS -std=c++11 -Wl,--gc-sections -fxray-instrument)
   list(APPEND LDFLAGS -fxray-instrument)
   llvm_test_run(--benchmark_filter=dummy_skip_ignore)
-  llvm_test_executable(retref-bench retref-bench.cc)
-  target_link_libraries(retref-bench benchmark)
+  llvm_test_executable(fdrmode-bench fdrmode-bench.cc)
+  target_link_libraries(fdrmode-bench benchmark)
 
-  file(COPY retref-bench_BM_ReturnNeverInstrumented.test
+  file(COPY fdrmode-bench_BM_XRayFDRMultiThreaded_1_thread.test
        DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-  file(COPY retref-bench_BM_ReturnInstrumentedUnPatched.test
+  file(COPY fdrmode-bench_BM_XRayFDRMultiThreaded_2_thread.test
        DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-  file(COPY retref-bench_BM_ReturnInstrumentedPatchedThenUnpatched.test
+  file(COPY fdrmode-bench_BM_XRayFDRMultiThreaded_4_thread.test
        DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-  file(COPY retref-bench_BM_ReturnInstrumentedPatched.test
+  file(COPY fdrmode-bench_BM_XRayFDRMultiThreaded_8_thread.test
        DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-  file(COPY retref-bench_BM_RDTSCP_Cost.test
+  file(COPY fdrmode-bench_BM_XRayFDRMultiThreaded_16_thread.test
        DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-  file(COPY retref-bench_BM_ReturnInstrumentedPatchedWithLogHandler.test
+  file(COPY fdrmode-bench_BM_XRayFDRMultiThreaded_32_thread.test
        DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
 endif()

MicroBenchmarks/XRay/FDRMode/fdrmode-bench.cc

+//===- fdrmode-bench.cc - XRay Instrumentation Benchmarks ------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Define benchmarks for measuring the cost of XRay instrumentation when using
+// flight data recorder mode.
+//
+//===----------------------------------------------------------------------===//
+
+#include <assert.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include "benchmark/benchmark.h"
+#include "xray/xray_interface.h"
+#include "xray/xray_log_interface.h"
+
+namespace {
+
+// This needs to be a global value so that the compiler doesn't end up writing
+// to data on the stack. We also mark it volatile to preserve all the loads and
+// stores performed on this variable.
+volatile int val = 0;
+
+__xray::FDRLoggingOptions Options;
+
+}  // namespace
+
+// We define a multi-threaded benchmark which measures the overall costs
+// introduced by the XRay handlers upstream. This will exercise a tight loop
+// calling a single function that practically does nothing.
+[[clang::xray_always_instrument]] __attribute__((noinline)) __attribute__((weak)) int
+EmptyFunction() {
+  return 0;
+}
+
+volatile bool log_initialized = false;
+
+// Force installation of the FDR logging implementation upstream, with the
+// caveat that we're writing the log out to /dev/null.
+[[clang::xray_never_instrument]] void SetUpXRayFDRMultiThreaded(
+    benchmark::State& state) {
+  if (!log_initialized) {
+    Options.ReportErrors = true;
+    Options.Fd = open("/dev/null", O_WRONLY);
+    assert((Options.Fd != -1) && "Cannot open /dev/null!");
+    __xray_log_init(getpagesize(), 1 << 16, &Options,
+                    sizeof(__xray::FDRLoggingOptions));
+    __xray_remove_customevent_handler();
+    __xray_patch();
+    log_initialized = true;
+  }
+}
+
+[[clang::xray_never_instrument]] void TearDownXRayFDRMultiThreaded(
+    benchmark::State& state) {
+  if (log_initialized) {
+    log_initialized = false;
+    __xray_log_finalize();
+    __xray_log_flushLog();
+    __xray_unpatch();
+  }
+}
+
+[[clang::xray_never_instrument]] static void BM_XRayFDRMultiThreaded(
+  benchmark::State& state) {
+  if (state.thread_index == 0) {
+    SetUpXRayFDRMultiThreaded(state);
+  }
+  while (state.KeepRunning()) {
+    val = EmptyFunction();
+    benchmark::DoNotOptimize(val);
+  }
+  if (state.thread_index == 0) {
+    TearDownXRayFDRMultiThreaded(state);
+  }
+}
+
+BENCHMARK(BM_XRayFDRMultiThreaded)
+    ->ThreadRange(1, 32);  // Number of threads
+
+BENCHMARK_MAIN();

MicroBenchmarks/XRay/FDRMode/fdrmode-bench_BM_XRayFDRMultiThreaded_16_thread.test

+RUN: %S/fdrmode-bench --benchmark_repetitions=10 --benchmark_report_aggregates_only=true --benchmark_filter=BM_XRayFDRMultiThreaded/threads:16$

MicroBenchmarks/XRay/FDRMode/fdrmode-bench_BM_XRayFDRMultiThreaded_1_thread.test

+RUN: %S/fdrmode-bench --benchmark_repetitions=10 --benchmark_report_aggregates_only=true --benchmark_filter=BM_XRayFDRMultiThreaded/threads:1$

MicroBenchmarks/XRay/FDRMode/fdrmode-bench_BM_XRayFDRMultiThreaded_2_thread.test

+RUN: %S/fdrmode-bench --benchmark_repetitions=10 --benchmark_report_aggregates_only=true --benchmark_filter=BM_XRayFDRMultiThreaded/threads:2$

MicroBenchmarks/XRay/FDRMode/fdrmode-bench_BM_XRayFDRMultiThreaded_32_thread.test

+RUN: %S/fdrmode-bench --benchmark_repetitions=10 --benchmark_report_aggregates_only=true --benchmark_filter=BM_XRayFDRMultiThreaded/threads:32$

MicroBenchmarks/XRay/FDRMode/fdrmode-bench_BM_XRayFDRMultiThreaded_4_thread.test

+RUN: %S/fdrmode-bench --benchmark_repetitions=10 --benchmark_report_aggregates_only=true --benchmark_filter=BM_XRayFDRMultiThreaded/threads:4$

MicroBenchmarks/XRay/FDRMode/fdrmode-bench_BM_XRayFDRMultiThreaded_8_thread.test

+RUN: %S/fdrmode-bench --benchmark_repetitions=10 --benchmark_report_aggregates_only=true --benchmark_filter=BM_XRayFDRMultiThreaded/threads:8$

MicroBenchmarks/XRay/FDRMode/lit.local.cfg

-config.environment['XRAY_OPTIONS'] = 'patch_premain=false xray_naive_log=false'
+config.environment['XRAY_OPTIONS'] = 'patch_premain=false xray_naive_log=false xray_fdr_log=true'
 test_modules = config.test_modules
 if 'run' in test_modules:
     # Insert microbenchmark module behind 'run'
     test_modules.insert(test_modules.index('run')+1, 'microbenchmark')
     # Timeit results are not useful for microbenchmarks
     if 'timeit' in test_modules:
         test_modules.remove('timeit')

MicroBenchmarks/XRay/ReturnReference/CMakeLists.txt

 check_cxx_compiler_flag(-fxray-instrument COMPILER_HAS_FXRAY_INSTRUMENT)
 if(ARCH STREQUAL "x86" AND COMPILER_HAS_FXRAY_INSTRUMENT)
   file(COPY lit.local.cfg DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
 
   list(APPEND CPPFLAGS -std=c++11 -Wl,--gc-sections -fxray-instrument)
   list(APPEND LDFLAGS -fxray-instrument)
   llvm_test_run(--benchmark_filter=dummy_skip_ignore)
   llvm_test_executable(retref-bench retref-bench.cc)
   target_link_libraries(retref-bench benchmark)
 
   file(COPY retref-bench_BM_ReturnNeverInstrumented.test
        DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
   file(COPY retref-bench_BM_ReturnInstrumentedUnPatched.test
        DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
   file(COPY retref-bench_BM_ReturnInstrumentedPatchedThenUnpatched.test
        DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
   file(COPY retref-bench_BM_ReturnInstrumentedPatched.test
        DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
   file(COPY retref-bench_BM_RDTSCP_Cost.test
        DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
   file(COPY retref-bench_BM_ReturnInstrumentedPatchedWithLogHandler.test
        DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
 endif()

MicroBenchmarks/XRay/ReturnReference/lit.local.cfg

 config.environment['XRAY_OPTIONS'] = 'patch_premain=false xray_naive_log=false'
 test_modules = config.test_modules
 if 'run' in test_modules:
     # Insert microbenchmark module behind 'run'
     test_modules.insert(test_modules.index('run')+1, 'microbenchmark')
     # Timeit results are not useful for microbenchmarks
     if 'timeit' in test_modules:
         test_modules.remove('timeit')

MicroBenchmarks/XRay/ReturnReference/retref-bench.cc

 //===- retref-bench.cc - XRay Instrumentation Benchmarks ------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // Define benchmarks for measuring the cost of XRay instrumentation (the sleds,
 // the trampolines).
 //
 //===----------------------------------------------------------------------===//
 
 #include <x86intrin.h>
 
 #include "benchmark/benchmark.h"
 #include "xray/xray_interface.h"
 
 [[clang::xray_never_instrument]] __attribute__((noinline)) int
 neverInstrumented() {
   benchmark::ClobberMemory();
   return 0;
 }
 
 [[clang::xray_never_instrument]] static void BM_ReturnNeverInstrumented(
     benchmark::State& state) {
   while (state.KeepRunning()) {
     benchmark::DoNotOptimize(neverInstrumented());
   }
 }
 
 BENCHMARK(BM_ReturnNeverInstrumented);
 
 [[clang::xray_always_instrument]] __attribute__((noinline)) int
 alwaysInstrumented() {
   benchmark::ClobberMemory();
   return 0;
 }
 
 [[clang::xray_never_instrument]] static void BM_ReturnInstrumentedUnPatched(
     benchmark::State& state) {
   __xray_unpatch();
   while (state.KeepRunning()) {
     int x;
     benchmark::DoNotOptimize(x = alwaysInstrumented());
     benchmark::ClobberMemory();
   }
 }
 
 BENCHMARK(BM_ReturnInstrumentedUnPatched);
 
 
 [[clang::xray_never_instrument]] static void BM_ReturnInstrumentedPatchedThenUnpatched(
     benchmark::State& state) {
   __xray_patch();
   __xray_unpatch();
   while (state.KeepRunning()) {
     int x;
     benchmark::DoNotOptimize(x = alwaysInstrumented());
     benchmark::ClobberMemory();
   }
 }
 
 BENCHMARK(BM_ReturnInstrumentedPatchedThenUnpatched);
 
 
 [[clang::xray_never_instrument]] static void BM_ReturnInstrumentedPatched(
     benchmark::State& state) {
   __xray_patch();
   while (state.KeepRunning()) {
     int x;
     benchmark::DoNotOptimize(alwaysInstrumented());
     benchmark::ClobberMemory();
   }
 }
 
 BENCHMARK(BM_ReturnInstrumentedPatched);
 
 [[clang::xray_never_instrument]] static void BM_RDTSCP_Cost(
     benchmark::State& state) {
   while (state.KeepRunning()) {
     unsigned cpu;
     unsigned tsc;
     benchmark::DoNotOptimize(tsc = __rdtscp(&cpu));
     benchmark::ClobberMemory();
   }
 }
 
 volatile unsigned global_cpu;
 volatile unsigned tsc;
 [[clang::xray_never_instrument]] void benchmark_handler(int32_t,
                                                         XRayEntryType) {
   unsigned cpu;
   benchmark::DoNotOptimize(tsc = __rdtscp(&cpu));
   global_cpu = cpu;
   benchmark::ClobberMemory();
 }
 
 BENCHMARK(BM_RDTSCP_Cost);
 
 [[clang::xray_never_instrument]] static void
 BM_ReturnInstrumentedPatchedWithLogHandler(benchmark::State& state) {
   __xray_set_handler(benchmark_handler);
   __xray_patch();
   benchmark::ClobberMemory();
   while (state.KeepRunning()) {
     int x;
     benchmark::DoNotOptimize(x = alwaysInstrumented());
     benchmark::ClobberMemory();
   }
   __xray_remove_handler();
 }
 
 BENCHMARK(BM_ReturnInstrumentedPatchedWithLogHandler);
 
 BENCHMARK_MAIN();

MicroBenchmarks/XRay/ReturnReference/retref-bench_BM_RDTSCP_Cost.test

 RUN: %S/retref-bench --benchmark_repetitions=10 --benchmark_report_aggregates_only=true --benchmark_filter=BM_RDTSCP_Cost

MicroBenchmarks/XRay/ReturnReference/retref-bench_BM_ReturnInstrumentedPatched.test

 RUN: %S/retref-bench --benchmark_repetitions=10 --benchmark_report_aggregates_only=true --benchmark_filter=BM_ReturnInstrumentedPatched

MicroBenchmarks/XRay/ReturnReference/retref-bench_BM_ReturnInstrumentedPatchedThenUnpatched.test

 RUN: %S/retref-bench --benchmark_repetitions=10 --benchmark_report_aggregates_only=true --benchmark_filter=BM_ReturnInstrumentedPatchedThenUnpatched

MicroBenchmarks/XRay/ReturnReference/retref-bench_BM_ReturnInstrumentedPatchedWithLogHandler.test

 RUN: %S/retref-bench --benchmark_repetitions=10 --benchmark_report_aggregates_only=true --benchmark_filter=BM_ReturnInstrumentedPatchedWithLogHandler

MicroBenchmarks/XRay/ReturnReference/retref-bench_BM_ReturnInstrumentedUnPatched.test

 RUN: %S/retref-bench --benchmark_repetitions=10 --benchmark_report_aggregates_only=true --benchmark_filter=BM_ReturnInstrumentedUnPatched

MicroBenchmarks/XRay/ReturnReference/retref-bench_BM_ReturnNeverInstrumented.test

 RUN: %S/retref-bench --benchmark_repetitions=10 --benchmark_report_aggregates_only=true --benchmark_filter=BM_ReturnNeverInstrumented

MicroBenchmarks/XRay/lit.local.cfg

-config.environment['XRAY_OPTIONS'] = 'patch_premain=false xray_naive_log=false'
-test_modules = config.test_modules
-if 'run' in test_modules:
-    # Insert microbenchmark module behind 'run'
-    test_modules.insert(test_modules.index('run')+1, 'microbenchmark')
-    # Timeit results are not useful for microbenchmarks
-    if 'timeit' in test_modules:
-        test_modules.remove('timeit')