On Tue, Jun 02, 2009 at 01:41:05PM -0400, Gregory Haskins wrote: > > And having close not clean up the state unless you do an ioctl first is > > very messy IMO - I don't think you'll find any such examples in kernel. > > > > > > I agree, and that is why I am advocating this POLLHUP solution. It was > only this other way to begin with because the technology didn't exist > until Davide showed me the light. > > Problem with your request is that I already looked into what is > essentially a bi-directional reference problem (for a different reason) > when I started the POLLHUP series. Its messy to do this in a way that > doesn't negatively impact the fast path (introducing locking, etc) or > make my head explode making sure it doesn't race. Afaict, we would need > to solve this problem to do what you are proposing (patches welcome). > > If this hybrid decoupled-deassign + unified-close is indeed an important > feature set, I suggest that we still consider this POLLHUP series for > inclusion, and then someone can re-introduce DEASSIGN support in the > future as a CAP bit extension. That way we at least get the desirable > close() properties that we both seem in favor of, and get this advanced > use case when we need it (and can figure out the locking design). >
FWIW, I took a look and yes, it is non-trivial. I concur, we can always add the deassign ioctl later. -- MST -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
