On Thu, Dec 29, 2011 at 04:35:36PM +0200, Avi Kivity wrote: > On 12/29/2011 04:18 PM, Isaku Yamahata wrote: > > > > > > > > The issue is how to solve the page fault, not whether > > > > TASK_INTERRUPTIBLE or > > > > TASK_UNINTERRUPTIBLE. > > > > I can think of several options. > > > > - When daemon X is dead, all page faults are served by zero pages. > > > > - When daemon X is dead, all page faults are resovled as VM_FAULT_SIGBUS > > > > - list/reattach: complications. You don't like it > > > > - other? > > > > > > Don't resolve the page fault. It's up to the user/system to make sure > > > it happens. qemu can easily do it by watching for the daemon's death > > > and respawning it. > > > > > > When the new daemon is started, it can ask the kernel for a list of > > > pending requests, and service them. > > > > Great, then we agreed with list/reattach basically. > > (Maybe identity scheme needs reconsideration.) > > I guess we miscommunicated. Why is reattach needed? If you have the > fd, nothing else is needed.
What if malicious process close the fd and does page fault intentionally? Unkillable process issue remains. I think we are talking not only qemu case but also general case. -- yamahata
