On Thu, 07 Apr 2011 10:43:25 -0700, Dave Hansen <dave@xxxxxxxxxxxxxxxxxx> wrote: > > The virtio balloon driver has a VIRTIO_BALLOON_F_MUST_TELL_HOST > feature bit. Whenever the bit is set, we must always tell the > host before we free pages back to the allocator. Without this > we might free a page (and have another user touch it) while the > hypervisor is unprepared for it. > > But, if the bit is _not_ set, we are under no obligation to > reverse the order. Furthermore, all modern qemus set this bit. > So, the "tell second" code is completely unused and untestable. > Quoting Anthony: "untested code is broken code". > > This _also_ means that we don't have to preserve a pfn list > after the pages are freed, which should let us get rid of some > temporary storage (vb->pfns) eventually. > > Signed-off-by: Dave Hansen <dave@xxxxxxxxxxxxxxxxxx> Thanks, applied! Rusty. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
