On 4/8/17, 11:13 AM, David Ahern wrote: > On 4/8/17 2:06 PM, Roopa Prabhu wrote: >> On 4/7/17, 2:25 PM, David Ahern wrote: >>> Changing MTU on a link currently causes 3 messages to be sent to userspace: >>> >>> [LINK]11: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1490 qdisc noqueue >>> state UNKNOWN group default event PRE_CHANGE_MTU >>> link/ether f2:52:5c:6d:21:f3 brd ff:ff:ff:ff:ff:ff >>> >>> [LINK]11: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue >>> state UNKNOWN group default event CHANGE_MTU >>> link/ether f2:52:5c:6d:21:f3 brd ff:ff:ff:ff:ff:ff >>> >>> [LINK]11: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue >>> state UNKNOWN group default >>> link/ether f2:52:5c:6d:21:f3 brd ff:ff:ff:ff:ff:ff >>> >>> Remove the PRE_CHANGE_MTU and CHANGE_MTU messages. >>> >>> >> This change is good... multiple notifications for the same event does not >> help in large scale links setups. However, this >> reverts what vlad was trying to do with his patchset. Vlad's patch-set >> relies on the rtnl notifications generated from >> notifiers (rtnetlink_event) to add specific event (IFLA_EVENT) in >> notifications. >> >> The third notification in your example above is the correct one and is an >> aggregate notification for a set of changes, but >> it cannot really fill in all types of events in the single IFLA_EVENT >> attribute as it stands today. IFLA_EVENT should be >> a bitmask to include all events in this case (i had indicated this in vlads >> first version). >> > Agreed. I think it would be best to revert def12888c161 before the UAPI > goes out. > > The change can instead add the IFLA_EVENT as a bitmask mentioned here to > note the changes in a setlink. On top of that, remove the notifications > for the events I mentioned in this set to reduce the overhead on userspace.
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