On 3/29/17 11:05 AM, Vlad Yasevich wrote: > On 03/29/2017 12:37 PM, Roopa Prabhu wrote: >> On 3/29/17, 5:23 AM, Vlad Yasevich wrote: >>> [ resending to list. hit the wrong reply button last time ] >>> >>> On 03/27/2017 06:58 PM, David Miller wrote: >>>> From: Vladislav Yasevich <vyasev...@gmail.com> >>>> Date: Sat, 25 Mar 2017 21:59:47 -0400 >>>> >>>>> RTNL currently generates notifications on some netdev notifier events. >>>>> However, user space has no idea what changed. All it sees is the >>>>> data and has to infer what has changed. For some events that is not >>>>> possible. >>>>> >>>>> This patch adds a new field to RTM_NEWLINK message called IFLA_EVENT >>>>> that would have an encoding of the which event triggered this >>>>> notification. Currectly, only 2 events (NETDEV_NOTIFY_PEERS and >>>>> NETDEV_MTUCHANGED) are supported. These events could be interesting >>>>> in the virt space to trigger additional configuration commands to VMs. >>>>> Other events of interest may be added later. >>>>> >>>>> Signed-off-by: Vladislav Yasevich <vyase...@redhat.com> >>>> At what point do we start providing the metadata for the changed >>>> values as well? You'd probably need to provide both the old and >>>> new values to cover all cases. >>> I don't think if that would be possible because of when events are >>> triggered. >>> We send these notifications after all the changes have already been made, so >>> it might be tough to carry old data. >>> >>> Looking at just the two events I am supporting in this patch, we could >>> actually >>> supply the old mtu data through a NETDEV_PRECHANGEMTU event, if it is >>> necessary. >> >> But, NETDEV_PRECHANGEMTU will be a unnecessary notification to userspace >> without >> changes. There are already enough notifications generated for links (I know >> you are not >> suggesting adding it here) > > Actually, this one already triggers a link notification to userspace. It > just has > no event data in it to tell you that. :)
Is it intentional or unintentional? perhaps rtnetlink_event should be a whitelist -- events that userspace should be notified about. Seems like NETDEV_ events have been added without rtnetlink_event getting updated. For example, does userspace care about NETDEV_UDP_TUNNEL_PUSH_INFO or NETDEV_CHANGE_TX_QUEUE_LEN?
