From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roopa Prabhu Subject: Re: [PATCH net-next 1/8] rtnetlink: Do not generate notifications for MTU events Date: Sat, 08 Apr 2017 11:18:14 -0700 Message-ID: <58E92966.5000506@cumulusnetworks.com> References: <1491600340-8359-1-git-send-email-dsa@cumulusnetworks.com> <1491600340-8359-2-git-send-email-dsa@cumulusnetworks.com> <58E92699.6090909@cumulusnetworks.com> <63e0a6c1-ec09-4f04-7e41-edd0adf871b2@cumulusnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, vyasevic@redhat.com, davem@davemloft.net To: David Ahern Return-path: Received: from mail-pg0-f48.google.com ([74.125.83.48]:35861 "EHLO mail-pg0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751166AbdDHSSS (ORCPT ); Sat, 8 Apr 2017 14:18:18 -0400 Received: by mail-pg0-f48.google.com with SMTP id g2so85957051pge.3 for ; Sat, 08 Apr 2017 11:18:18 -0700 (PDT) In-Reply-To: <63e0a6c1-ec09-4f04-7e41-edd0adf871b2@cumulusnetworks.com> Sender: netdev-owner@vger.kernel.org List-ID: 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: 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: 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: 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. ack