Il 12/06/2013 10:11, Benjamin Herrenschmidt ha scritto: > On Wed, 2013-06-12 at 10:00 -0400, Paolo Bonzini wrote: >> 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. > > Right, do we have a way to madvise "throw away" these instead ?
We already do that, but apparently that madvise is asynchronous. > Or do we > have a way to track that the platform init code did write something > there and only clear *those* pages ? No need for; since it's copy-on-write, not copy-on-read :) we can just check for pages that are zero and not rewrite them with zeros. That's what Peter's patches do, I'll review them right away. Paolo
