BOOL MySetLockPagesPrivilege(HANDLE hProcess, BOOL bEnable)
{
   struct {
      DWORD Count;
      LUID_AND_ATTRIBUTES Privilege[1];
   } Info;
   HANDLE Token;
   if ( !OpenProcessToken(hProcess, TOKEN_ADJUST_PRIVILEGES, &Token) ) {
      printf("Cannot open process token.\n");
      return FALSE;
   }
   Info.Count = 1;
   if (bEnable) {
      Info.Privilege[0].Attributes = SE_PRIVILEGE_ENABLED;
   }
   else {
      Info.Privilege[0].Attributes = 0;
   }
   if ( !LookupPrivilegeValue(NULL, SE_LOCK_MEMORY_NAME, &(Info.Privilege[0].Luid)) ) {
      printf("Cannot get privilege for %s.\n", SE_LOCK_MEMORY_NAME);
      return FALSE;
   }
   if ( !AdjustTokenPrivileges(Token, FALSE, (PTOKEN_PRIVILEGES)&Info, 0, NULL, NULL) )  {
      printf ("Cannot adjust token privileges (%u)\n", GetLastError());
      return FALSE;
   }
   // ERROR_NOT_ALL_ASSIGNED
   // 1300 (0x514)
   // Not all privileges or groups referenced are assigned to the caller.
   DWORD dwErr = GetLastError();
   printf("AdjustTokenPrivileges dwErr=%u\n", dwErr);
   if (dwErr != ERROR_SUCCESS) {
      printf("Cannot enable the SE_LOCK_MEMORY_NAME privilege");
      return FALSE;
   }
   CloseHandle(Token);
   return TRUE;
}

void LargeMemInit()
{
   if ( !MySetLockPagesPrivilege(GetCurrentProcess(), TRUE) ) {
      fprintf(stderr, "MySetLockPagesPrivilege failed.\n");
      exit(1);
   }
}

// VirtualAlloc may fail with: ERROR_NO_SYSTEM_RESOURCES = 1450. To fix, reboot.
static void* my_big_malloc(size_t s)
{
   DWORD dwErr;
   void* pMem;
   pMem = VirtualAlloc(
      NULL,                           // Let system decide where to allocate it
      s,                              // size of memory block
      MEM_RESERVE | MEM_COMMIT | MEM_LARGE_PAGES,
      PAGE_READWRITE
   );
   if (pMem == NULL) {
      // Error 1314 = ERROR_PRIVILEGE_NOT_HELD
      dwErr = GetLastError();
      fprintf(stderr, "VirtualAlloc failed: dwError=%d\n", (int)dwErr);
      exit(1);
   }
   printf("VirtualAlloc ok p=%p\n", pMem);
   return pMem;
}