From: Florian Westphal <f...@strlen.de>
Date: Wed, 9 Aug 2017 20:41:46 +0200
> Changes since v1:
> In patch 6, don't make ipv6 route handlers lockless, they all have
> assumptions on rtnl being held. Other patches are unchanged.
>
> The RTNL mutex is used to serialize both rtnetlink calls and
> dump requests.
> Its also used to protect other things such as the list of current
> net namespaces.
>
> Unfortunately RTNL mutex is a performance issue, e.g. a cpu adding an
> ip address prevents other cpus from seemingly unrelated tasks such as
> dumping tc classifiers or doing rtnetlink route lookups.
>
> This patch set adds basic infrastructure to start pushing the rtnl lock
> down to those places that need it, or even elide it entirely in some cases.
>
> Subsystems can now indicate that their doit() callback can run without
> RTNL mutex, such callbacks can then run in parallel.
>
> This will obviously need a lot of followup work; all current
> users need to be audited/changed to benefit from this.
> Initial no-rtnl spot is netns new/getid.
>
> We have various 'get' handlers that are also a tempting target,
> however, several of these depend on rtnl mutex to prevent information
> from changing while objects are being read by rtnl handlers; however,
> it doesn't appear impossible to change this.
>
> Dumps are another problem entirely, see
> commit 2907c35ff64708065 ("net: hold rtnl again in dump callbacks"),
> this patchset doesn't touch dump requests.
Ok series applied, let's see where this goes :-)
