Hugh, Great topics. As per one of Rik original points: > 4) skip writeout of zero-filled pages - this can be a big help > for KVM virtual machines running Windows, since Windows zeroes > out free pages; simply discarding a zero-filled page is not > at all simple in the current VM, where we would have to iterate > over all the ptes to free the swap entry before being able to > free the swap cache page (I am not sure how that locking would > even work) > > with the extra layer of indirection, the locking for this scheme > can be trivial - either the faulting process gets the old page, > or it gets a new one, either way it'll be zero filled > Since it's KVMs realm here, can't KSM simply solve the zero-filled pages problem avoiding unnecessary burden for the Swap subsystem? Cheers, Luca -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html