Flush File Read Cache

Question

How do I flush (empty) the windows file read cache using C++ win32api?

Answer 1

Try DeviceIoControl with IOCTL_DISK_SET_CACHE_INFORMATION.

Answer 2

I don't think you can (you could flush write cache), but you could always open your file via CreateFile with FILE_FLAG_NO_BUFFERING. This way, your reads would not be from the system cache, but straight from your device (which may cache data).