From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jiri Pirko <jiri@resnulli.us>
Subject: Re: [RFC PATCH net-next v6 4/4] netvsc: refactor notifier/event
	handling code to use the bypass framework
Date: Wed, 11 Apr 2018 09:50:20 +0200
Message-ID: <20180411075020.GJ2028__39003.2475268983$1523432923$gmane$org@nanopsycho>
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	<20180410142608.50f15b45@xeon-e3>
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To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: alexander.h.duyck@intel.com, virtio-dev@lists.oasis-open.org, kubakici@wp.pl, Sridhar Samudrala <sridhar.samudrala@intel.com>, virtualization@lists.linux-foundation.org, loseweigh@gmail.com, netdev@vger.kernel.org, davem@davemloft.net
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Wed, Apr 11, 2018 at 01:28:51AM CEST, mst@redhat.com wrote:
>On Tue, Apr 10, 2018 at 02:26:08PM -0700, Stephen Hemminger wrote:
>> On Tue, 10 Apr 2018 11:59:50 -0700
>> Sridhar Samudrala <sridhar.samudrala@intel.com> wrote:
>> 
>> > Use the registration/notification framework supported by the generic
>> > bypass infrastructure.
>> > 
>> > Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
>> > ---
>> 
>> Thanks for doing this.  Your current version has couple show stopper
>> issues.
>> 
>> First, the slave device is instantly taking over the slave.
>> This doesn't allow udev/systemd to do its device rename of the slave
>> device. Netvsc uses a delayed work to workaround this.
>
>Interesting. Does this mean udev must act within a specific time window
>then?

Yeah. That is scarry. Also, wrong.


>
>> Secondly, the select queue needs to call queue selection in VF.
>> The bonding/teaming logic doesn't work well for UDP flows.
>> Commit b3bf5666a510 ("hv_netvsc: defer queue selection to VF")
>> fixed this performance problem.
>> 
>> Lastly, more indirection is bad in current climate.
>> 
>> I am not completely adverse to this but it needs to be fast, simple
>> and completely transparent.