add --rio flag to use winsock registered i/o extension

README.md

@@ -18,6 +18,7 @@ un-REM the clang++ line to build with clang if you have it installed.
 Option | Description
 ------------ | -------------
 --large | Use 2mb pages (default: 4k pages)
+--rio | register allocated memory with [RIORegisterBuffer][] function
 [number] | Set total allocation size in mb (default: 1024)
 
 ### Usage examples:
@@ -42,3 +43,5 @@ In this simple benchmark, 2mb pages outperform 4k pages dramatically - by number
 Alas, no such flag exists, so this is purely hypothetical at the moment.
 
 \- [Casey](https://caseymuratori.com)
+
+[RIORegisterBuffer]: https://docs.microsoft.com/en-us/windows/win32/api/mswsock/nc-mswsock-lpfn_rioregisterbuffer

build.bat

@@ -1,3 +1,3 @@
 @echo off
-call cl -nologo -O2 largepages.cpp advapi32.lib
-REM call clang++ -O2 -fuse-ld=lld -Wl,-subsystem:console,advapi32.lib largepages.cpp -o largepages.exe
+call cl -nologo -O2 largepages.cpp advapi32.lib ws2_32.lib
+REM call clang++ -O2 -fuse-ld=lld -Wl,-subsystem:console,advapi32.lib,ws2_32.lib largepages.cpp -o largepages.exe

largepages.cpp

@@ -1,3 +1,5 @@
+#include <winsock2.h>
+#include <mswsock.h>
 #include <windows.h>
 #include <stdio.h>
 #include <immintrin.h>
@@ -52,6 +54,7 @@ int main(int ArgCount, char **Args)
  int Result = 0;
 
  int TryLargePages = false;
+ int TryRio = false;
 
  SIZE_T Kilobyte = 1024;
  SIZE_T Megabyte = 1024*1024;
@@ -70,6 +73,10 @@ int main(int ArgCount, char **Args)
  {
  TryLargePages = true;
  }
+ else if(strcmp(Arg, "--rio") == 0)
+ {
+ TryRio = true;
+ }
  else
  {
  int IsNum = true;
@@ -106,13 +113,31 @@ int main(int ArgCount, char **Args)
  //
 
  SIZE_T AllocSize = PageSize * ((TotalSize + PageSize - 1) / PageSize);
+
+ RIO_EXTENSION_FUNCTION_TABLE Rio = {};
+ if (TryRio)
+ {
+ // NOTE(mmozeiko): need to get function pointers to RIO functions, and that requires dummy socket
+ WSADATA WinSockData;
+ WSAStartup(MAKEWORD(2, 2), &WinSockData);
+
+ GUID Guid = WSAID_MULTIPLE_RIO;
+ DWORD RioBytes = 0;
+ SOCKET Sock = socket(AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP);
+ WSAIoctl(Sock, SIO_GET_MULTIPLE_EXTENSION_FUNCTION_POINTER, &Guid, sizeof(Guid), (void**)&Rio, sizeof(Rio), &RioBytes, 0, 0);
+ closesocket(Sock);
+ }
 
  // NOTE(casey): Timed portion begins here
  // {
 
  // NOTE(casey): "Allocate" memory
  LARGE_INTEGER Start; QueryPerformanceCounter(&Start);
  char *Memory = (char *)VirtualAlloc(0, AllocSize, VirtualAllocFlags, PAGE_READWRITE);
+ if (TryRio)
+ {
+ Rio.RIODeregisterBuffer(Rio.RIORegisterBuffer(Memory, AllocSize));
+ };
  LARGE_INTEGER Mid; QueryPerformanceCounter(&Mid);
 
  if(Memory)