On Thu, Aug 01, 2013 at 05:31:44AM -0400, Antoni Segura Puimedon wrote: > Looking at clientIF.py on the patch Michal pointed to, concretely on: > > + def removeVmFromMonitoredDomains(self, vmId): > + for dom in self.domainVmIds: > + #only take lock here to allow runVm to take the lock in-between > + with self.domainVmIdsLock: > + try: > + self.domainVmIds[dom].remove(vmId) > + except ValueError: > + pass > + else: > + if not self.domainVmIds[dom]: > + del self.domainVmIds[dom] > > > If there is no exception we will be deleting an element from a dictionary > while > iterating it. This is dangerous and should be avoided. The fastest alternative > to implement would be that in the "else" we append dom to a list of > domainsToRemove > and after the iteration we get a lock and remove all of them.
Alternatively, I believe we could do without maintaining the domain->vmId mapping. I did not understand why having each VM hold its domains is not enough. The said patch has another problem - a single SIGSTOPped qemu process can block all SPM operations (in case its storage domain has become active again and we attempt to cont the VM). Dan. _______________________________________________ vdsm-devel mailing list firstname.lastname@example.org https://lists.fedorahosted.org/mailman/listinfo/vdsm-devel