[ovs-dev] [netlink 03/16] datapath: Merge "struct dp_port" into "struct vport".

[Ben Pfaff]

On Fri, Nov 05, 2010 at 11:05:14AM -0700, Jesse Gross wrote:
> On Fri, Nov 5, 2010 at 10:52 AM, Ben Pfaff <blp at nicira.com> wrote:
> > On Thu, Nov 04, 2010 at 05:28:36PM -0700, Jesse Gross wrote:
> >> Actually what we should do it use the lockdep annotations available in
> >> new kernels to check that we really have RCU read lock or RTNL where
> >> we think we do.
> >
> > I see how to mark a function as acquiring or releasing a lock, and how
> > to mark an object as protected by RCU.  But how do I annotate a function
> > as requiring RCU or RTNL?  (I'm not sure whether you mean an annotation
> > for sparse or lockdep; many of the new annotations seem to be for
> > sparse.)
> 
> By new kernels, I really mean unreleased kernels...
> 
> 2.3.37 introduces rcu_dereference_rtnl(), using lockdep to check that
> either rcu_read_lock or RTNL is held.  That's what I was talking
> about, I guess it's not really an annotation per se.

Sounds useful.  I'm personally nervous about starting to use new kernel
features before they are part of a release, so I'll leave that bit for
later.

> There's also __rcu for sparse.

Right, I noticed that one.