On Thu, Jul 18, 2019 at 01:29:14PM -0700, Alexander Duyck wrote: > So one thing that is still an issue then is that my approach would > only work on the first migration. The problem is the logic I have > implemented assumes that once we have hinted on a page we don't need > to do it again. However in order to support migration you would need > to reset the hinting entirely and start over again after doing a > migration. Well with precopy at least it's simple: just clear the dirty bit, it won't be sent, and then on destination you get a zero page and later COW on first write. Right? With precopy it is tricker as destination waits until it gets all of memory. I think we could use some trick to make source pretend it's a zero page, that is cheap to send. -- MST
