<html><head></head><body><div class="ydpc0157d73yahoo-style-wrap" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;"><div></div> <div>Perhaps I didn't express my question precisely. I understand that you are talking about the mmap function in the kernel which is usually a function pointer in vm_operations...</div><div><br></div><div>My question is about the userspace structure of X11. IIUC, we have X11 clients, which are GUI apps.</div><div>They have a portion of the X11 related libraries (those needed for clients) mapped into their address space. As the app and the X11 libraries (client code in X11) are in the same address space the graphical data are accessible by both. Xserver is a separate process (i.e., Xorg). How are the graphical data sent to the server? Does it use shared memory? Multiple shared memory regions to service each client?</div><div><br></div><div>Is Opengl mapped only into the server portion?</div></div></body></html>