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在ceph 源码ceph-master\ceph-master\src\test\CMakeLists.txt 中定义了一个ceph_perf_local的可执行文件，用于测试不同平台对ceph性能的影响#ceph_perf_localadd_executable(ceph_perf_local   perf_local.cc  perf_helper.cc)if(HAVE_SSE)  set(PERF_LOCAL_FLAGS ${SSE3_FLAGS})endif(HAVE_SSE)if(HAVE_NEON)  set(PERF_LOCAL_FLAGS ${ARM_NEON_FLAGS})endif(HAVE_NEON)if(PERF_LOCAL_FLAGS)  set_target_properties(ceph_perf_local PROPERTIES COMPILE_FLAGS    ${PERF_LOCAL_FLAGS})endif()target_link_libraries(ceph_perf_local os global ${UNITTEST_LIBS})从makefile中可以看出ceph_perf_local的源文件有两个，分别是perf_local.cc/perf_helper.cc.其编译好的执行bin的name为ceph_perf_local，从makefile中同样可以看出可以使用x86的sse或者arm的neon 指令来加速这个tool的入口函数如下：int main(int argc, char *argv[]){  vector
   
     args;  argv_to_vec(argc, (const char **)argv, args);  auto cct = global_init(NULL, args, CEPH_ENTITY_TYPE_CLIENT,			 CODE_ENVIRONMENT_UTILITY, 0);  common_init_finish(g_ceph_context);  Cycles::init();  bind_thread_to_cpu(3);  #测试命令可以带一个参数，如果不带参数的话，则测试所有的item项  if (argc == 1) {    // No test names specified; run all tests.    for (size_t i = 0; i < sizeof(tests)/sizeof(TestInfo); ++i) {      run_test(tests[i]);    }  } else {    // Run only the tests that were specified on the command line.    for (int i = 1; i < argc; i++) {      bool found_test = false;      for (size_t j = 0; j < sizeof(tests)/sizeof(TestInfo); ++j) {        if (strcmp(argv[i], tests[j].name) == 0) {          found_test = true;          run_test(tests[j]);          break;        }      }      if (!found_test) {        int width = printf("%-24s ??", argv[i]);        printf("%*s No such test\n", 32-width, "");      }    }  }}从main函数中可以看出测试的item项在tests 这个数组中TestInfo tests[] = {  {"atomic_int_cmp", atomic_int_cmp,    "atomic_t::compare_and_swap"},  {"atomic_int_inc", atomic_int_inc,    "atomic_t::inc"},}}这里以atomic_int_inc的测试为例double atomic_int_inc(){  int count = 1000000;  #定义一个原子变量  std::atomic
    
      value = { 11 };  #对原子变量操作前获取时间  uint64_t start = Cycles::rdtsc();  #对这个原子变量自加1000000  for (int i = 0; i < count; i++) {    value++;  }  #原子变量自加完成后，读取时间  uint64_t stop = Cycles::rdtsc();  // printf("Final value: %d\n", value.load());  #计算本次原子变量自加占用的时间  return Cycles::to_seconds(stop - start)/count;}
    
   

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