Thx for pointing it out!
Actually, I did 'perthread = pthread_getspecific(perthread_key);' instead of
using 'ovsrcu_perthread_get()', which is wrong. Will fix it and remote the
call to ovsrcu_init_module().
On Fri, Sep 12, 2014 at 9:47 AM, Ben Pfaff <b...@nicira.com> wrote:
> On Tue, Sep 09, 2014 at 11:23:34AM -0700, Alex Wang wrote:
> > On current master, the per-thread callback event set is flushed
> > when ovsrcu_quiesce_start() is called or when the callback
> > event set is full. For threads that only call 'ovsrcu_quiesce()'
> > to indicate quiescient state, their callback event set will not
> > be flushed for execution until the set is full. And this could
> > take a very long time.
> >
> > Theoretically, this should not be an issue, since rcu postponed
> > callback events should only free the old version of objects.
> > However, current ovs does not follow this rule, and some callback
> > events include other activities like unregistering the netdev
> > from global name-netdev map. The delay of unregistering the netdev
> > (by threads that only calls ovsrcu_quiesce()) will prevent the
> > recreate of same netdev indefinitely.
> >
> > As a short-term workaround, this commit makes every call to
> > ovsrcu_quiesce() flush the callback event set. In the long run,
> > there will be a refactor of the use of ovs-rcu module, in which all
> > callback events only free the old version of objects.
> >
> > Signed-off-by: Alex Wang <al...@nicira.com>
> > ---
> > lib/ovs-rcu.c | 8 +++++++-
> > 1 file changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/lib/ovs-rcu.c b/lib/ovs-rcu.c
> > index a052d6c..6fe6103 100644
> > --- a/lib/ovs-rcu.c
> > +++ b/lib/ovs-rcu.c
> > @@ -138,8 +138,14 @@ ovsrcu_quiesce_start(void)
> > void
> > ovsrcu_quiesce(void)
> > {
> > + struct ovsrcu_perthread *perthread;
> > +
> > ovsrcu_init_module();
> > - ovsrcu_perthread_get()->seqno = seq_read(global_seqno);
> > + perthread = pthread_getspecific(perthread_key);
> > + perthread->seqno = seq_read(global_seqno);
> > + if (perthread->cbset) {
> > + ovsrcu_flush_cbset(perthread);
> > + }
> > seq_change(global_seqno);
>
> I think that we can remove the call to ovsrcu_init_module() because
> ovsrcu_perthread_get() calls it. (This was also true before your
> patch.)
>
> Acked-by: Ben Pfaff <b...@nicira.com>
>
_______________________________________________
dev mailing list
dev@openvswitch.org
http://openvswitch.org/mailman/listinfo/dev
