On Wed, 20 Feb 2008, Nick Piggin wrote: > I don't know how this is supposed to solve anything. The sleeping > problem happens I guess mostly in truncate. And all you are doing > is putting these rmap callbacks in page_mkclean and try_to_unmap.
truncate is handled by the range invalidates. This is special code to deal with the unnap/clean of an individual page. > That doesn't seem right. To start with, the new callbacks aren't > even called in the places where invalidate_page isn't allowed to > sleep. > > The problem is unmap_mapping_range, right? And unmap_mapping_range > must walk the rmaps with the mmap lock held, which is why it can't > sleep. And it can't hold any mmap_sem so it cannot prevent address Nope. unmap_mapping_range is already handled by the range callbacks. > So in the meantime, you could have eg. a fault come in and set up a > new page for one of the processes, and that page might even get > exported via the same external driver. And now you have a totally > inconsistent view. The situation that you are imagining has already been dealt with by the earlier patches. This is only to allow sleeping while unmapping individual pages. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
