On Dec 3, 2007 4:25 PM, Leland Lucius <[EMAIL PROTECTED]> wrote: > I realize that VDISK is special in the world of Linux, but why doesn't > someone give us the option of preventing this? Looks to me like adding one > line in swapfile.c would allow pages to cluster at the beginning of a disk > instead of running to the end and starting over at the beginning.
It's may not be a good idea to do sequential scanning of swap slots, but a push down stack of free slots might be cute. An even better alternative that we discussed on linux-390 is to have a facility to make Linux tell VM to drop the page from disk (makes also sense for COW devices). But this is chicken & egg: there's nothing now and if you make it, there's nothing that uses it... Some restrictions that Linux puts on I/O requests are self-imposed and not all necessary on ECKD, and certainly not on VDISK. But again, changes to the main kernel sources just for one architecture will not come easily. Rob -- Rob van der Heij Velocity Software, Inc http://velocitysoftware.com/
