On Fri, 18 May 2007, Nick Piggin wrote: > 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.
That is not a valid consideration anymore. There is virtual memmap update pending with the sparsemem folks that will simplify things. > Many batch operations on struct page are completely random, and as such, I > think it is better if each struct page fits completely into a single > cacheline even if it means being slightly larger. Right. That would simplify the calculations. > Don't let this space go to waste though, we can use page->virtual in order > to optimise page_address operations. page->virtual is a benefit if the page is cache hot. Otherwise it may cause a useless lookup. I wonder if there are other uses for the free space? - 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/