We are developing a Linux driver which allows a device to read/write directly into a processes virtual memory space. I have a question on using map_user_kiobuf() as we are having problems. I was under the impression that if I used map_user_kiobuf() this would map the users virtual address space into locked physical memory pages so that I/O could be performed. However, I note that if the user just mallocs memory and does not access it (No physical memory pages created) and then passes this virtual address space to the driver which performs a map_user_kiobuf() on it, the resulting kiobuf structure has all of the pagelist[] physical address entries set to the same value and the maplist[] entries set to 0. The devices access to this memory now causes system problems. Is map_user_kiobuf() working correctly ? Should I call some function to map the virtual address space into physical memory or at least pages before I call map_user_kiobuf() ? Cheers Terry -- Dr Terry Barnaby BEAM Ltd Phone: +44 1454 324512 Northavon Business Center, Dean Rd Fax: +44 1454 313172 Yate, Bristol, BS37 5NH, UK Email: [EMAIL PROTECTED] Web: www.beam.demon.co.uk BEAM for: Visually Impaired X-Terminals, Parallel Processing, Software Dev "Tandems are twice the fun !" - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/