On Wed, Mar 07, 2007 at 10:28:21AM +0100, Nick Piggin wrote: > Depending on whether anyone wants it, and what features they want, we > could emulate the old syscall, and make a new restricted one which is > much less intrusive. > For example, if we can operate only on MAP_ANONYMOUS memory and specify > that nonlinear mappings effectively mlock the pages, then we can get > rid of all the objrmap and unmap_mapping_range handling, forget about > the writeout and msync problems...
Anonymous-only would make it a doorstop for Oracle, since its entire motive for using it is to window into objects larger than user virtual address spaces (this likely also applies to UML, though they should really chime in to confirm). Restrictions to tmpfs and/or ramfs would likely be liveable, though I suspect some things might want to do it to shm segments (I'll ask about that one). There's definitely no need for a persistent backing store for the object to be remapped in Oracle's case, in any event. It's largely the in-core destination and source of IO, not something saved on-disk itself. -- wli - 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/
