On Wed, May 28, 2014 at 03:54:34PM -0700, Jarno Rajahalme wrote: > > On May 23, 2014, at 10:11 AM, Ben Pfaff <b...@nicira.com> wrote: > > > On Thu, May 22, 2014 at 05:37:40PM -0700, Jarno Rajahalme wrote: > >> lib/ovs-rcu.h had some of the comments duplicated. > >> > >> Add ovsrcu_init() that can be used like ovsrcu_set() when the RCU > >> protected pointer is not yet visible any readers. > >> > >> Use OVS_CONSTRUCTOR to initialize the ovs-rcu module. > >> > >> Signed-off-by: Jarno Rajahalme <jrajaha...@nicira.com> > > > > I get nervous to start to see modules using OVS_CONSTRUCTOR to do fairly > > complex work. Because there is no dependency system for constructors, > > the order in which they are invoked is unpredictable and can vary from > > one compiler or system to another. If we are not perfectly careful to > > make sure that there are no actual dependencies among them, then that > > can lead to surprising crashes at startup time. > > Yeah, I have struggled with nasty bugs due to this issue in the past, but > already forgot about the pain, apparently :-) > > in general, I like the idea of getting rid of checking for initialization > from all the possible entry points. > > We already have a ?module? system for VLOG, maybe we could generalize it to > include module initialization with some kind of dependency/priority system?
I agree that it's better to avoid needing to check for initialization, but I don't have a good idea for how to craft a dependency or priority system. Do you have some idea? > However, I totally see your point, we are calling non-trivial > functions here, so I am happy to roll this back for now. However, > I?d like to use the name ?ovsrcu_init? for the new purpose, as it > rhymes with ?atomic_init?, which has corresponding semantics. You > fine with using ovsrcu_init_module() instead: That's fine, thanks. > > I'm happy with the comment update. > > > > :-) :-) _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
