On Fri, 18 May 2007, Nick Piggin wrote: > > If we add 8 bytes to struct page on 64-bit machines, it becomes 64 bytes, > which is quite a nice number for cache purposes. > > However we don't have to let those 8 bytes go to waste: we can use them > to store the virtual address of the page, which kind of makes sense for > 64-bit, because they can likely to use complicated memory models.
Sooner rather than later, don't we need those 8 bytes to expand from atomic_t to atomic64_t _count and _mapcount? Not that we really need all 64 bits of both, but I don't know how to work atomically with less. (Why do I have this sneaking feeling that you're actually wanting to stick something into the lower bits of page->virtual?) Hugh - 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/