Il 08/06/2013 22:53, Benjamin Herrenschmidt ha scritto: > On Sun, 2013-06-09 at 10:16 +0800, Wenchao Xia wrote: >> If an page was not received and destination knows that page should >> exist according to total size, fill it with zero at destination, would >> it solve the problem? > > The easiest way to do that is to not write to those pages at the > destination to begin with, when initializing the VM... Is there any way > to know that a VM is being setup as a migration target or not ?
There is the "incoming" variable in vl.c (currently not a global), but I suspect Peter's patch could have also broken loadvm. It could quickly become a rat hole. The only bug we have is not a performance bug related to compression; it's that writing zero pages breaks overcommit. Let's fix that, and only that. Paolo
