[ovs-discuss] group chaining is not supported in OVS Switch 2.3.0 ?

[Ben Pfaff]

On Thu, Aug 28, 2014 at 04:31:42PM -0700, Sangho Shin wrote:
> I wonder if group chaining is not supported in OVS Switch 2.3.0.
> if I add a group to group, then I am getting CHAINING NOT SUPPORTED error.

Chaining is not supported, see xlate_group_resource_check() for an
explanation:

        /* Prevent nested translation of OpenFlow groups.
         *
         * OpenFlow allows this restriction.  We enforce this restriction only
         * because, with the current architecture, we would otherwise have to
         * take a possibly recursive read lock on the ofgroup rwlock, which is
         * unsafe given that POSIX allows taking a read lock to block if there
         * is a thread blocked on taking the write lock.  Other solutions
         * without this restriction are also possible, but seem unwarranted
         * given the current limited use of groups. */