Re: [libvirt] [PATCH v2 5/5] qemu: Enable memory-backend-file.discard-data whenever possible

On Tue, Apr 17, 2018 at 01:16:42PM +0200, Michal Privoznik wrote: > https://bugzilla.redhat.com/show_bug.cgi?id=1480668 > > The cases when we cannot enable this optimization are: > 1) nvdimms > 2) if memAccess='shared' > > Otherwise it is safe to enable it. This is basically saying that if memAccess==private, then no person/app cares about the contents of the memory-backend-file storage after QEMU has exited, because (implicitly) whatever data was in that storage is not going to be used again. While I accept that's going to be a common case, I'm wary of saying that is a 100% safe/valid assumption for every user. I tend think it should require an explicit opt-in to turn on this behaviour