Deniel, Daniel Lezcano wrote: > Pavel Emelianov wrote: > >>>>I did this at the very first version, but Alexey showed me that this >>>>would be wrong. Look. When we create the second device it must be in >>>>the other namespace as it is useless to have them in one namespace. >>>>But if we have the device in the other namespace the RTNL_NEWLINK >>>>message from kernel would come into this namespace thus confusing ip >>>>utility in the init namespace. Creating the device in the init ns and >>>>moving it into the new one is rather a complex task. >>>> >>>> >>> >>>Pavel, >>> >>>moving the netdevice to another namespace is not a complex task. Eric >>>Biederman did it in its patchset ( cf. http://lxc.sf.net/network ) >>> >> >>By saying complex I didn't mean that this is difficult to implement, >>but that it consists (must consist) of many stages. I.e. composite. >>Making the device right in the namespace is liter. >> >> >> >>>When the pair device is created, both extremeties are into the init >>>namespace and you can choose to which namespace to move one extremity. >>> >> >>I do not mind that. >> >> >>>When the network namespace dies, the netdev is moved back to the init >>>namespace. >>>That facilitate network device management. >>> >>>Concerning netlink events, this is automatically generated when the >>>network device is moved through namespaces. >>> >>>IMHO, we should have the network device movement between namespaces in >>>order to be able to move a physical network device too (eg. you have 4 >>>NIC and you want to create 3 containers and assign 3 NIC to each of them) >>> >> >>Agree. Moving the devices is a must-have functionality. >> >>I do not mind making the pair in the init namespace and move the second >>one into the desired namespace. But if we *always* will have two ends in >>different namespaces what to complicate things for? >> > > Just to provide a netdev sufficiently generic to be used by people who > don't want namespaces but just want to do some network testing, like Ben > Greear does. He mentioned in a previous email, he will be happy to stop > redirecting people to out of tree patch. > > https://lists.linux-foundation.org/pipermail/containers/2007-April/004420.html
no one is against generic code and ability to create 2 interfaces in *one* namespace. (Like we currently allow to do so in OpenVZ) However, believe me, moving an interface is a *hard* operation. Much harder then netdev register from the scratch. Because it requires to take into account many things like: - packets in flight which requires synchronize and is slow on big machines - asynchronous sysfs entries registration/deregistration from rtln_unlock -> netdev_run_todo - name/ifindex collisions - shutdown/cleanup of addresses/routes/qdisc and other similar stuff Thanks, Kirill - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
