On Wed, Jan 15, 2020 at 12:05 AM wrote: > From: Dennis Dalessandro > > On 1/14/2020 12:00 PM, Dennis Dalessandro wrote: > > On 1/14/2020 11:57 AM, Jason Gunthorpe wrote: > >> On Tue, Jan 14, 2020 at 09:53:45PM +0530, > >> madhuparnabhowmik04@gmail.com wrote: > >>> From: Madhuparna Bhowmik > >>> > >>> list_for_each_entry_rcu has built-in RCU and lock checking. > >>> Pass cond argument to list_for_each_entry_rcu. > >>> > >>> Signed-off-by: Madhuparna Bhowmik > >>> drivers/infiniband/hw/hfi1/verbs.c | 2 +- > >>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>> > >>> diff --git a/drivers/infiniband/hw/hfi1/verbs.c > >>> b/drivers/infiniband/hw/hfi1/verbs.c > >>> index 089e201d7550..22f2d4fd2577 100644 > >>> +++ b/drivers/infiniband/hw/hfi1/verbs.c > >>> @@ -515,7 +515,7 @@ static inline void hfi1_handle_packet(struct > >>> hfi1_packet *packet, > >>> opa_get_lid(packet->dlid, 9B)); > >>> if (!mcast) > >>> goto drop; > >>> - list_for_each_entry_rcu(p, &mcast->qp_list, list) { > >>> + list_for_each_entry_rcu(p, &mcast->qp_list, list, > >>> lockdep_is_held(&(ibp->rvp.lock))) { > >> > >> Okay, this looks reasonable > >> > >> Mike, Dennis, is this the right lock to test? > >> > > > > I'm looking at that right now actually, I don't think this is correct. > > Wanted to talk to Mike before I send a response though. > > > > -Denny > > That's definitely going to throw a ton of lock dep messages. It's not > really the right lock either. Instead what we probably need to do is > what we do in the non-multicast part of the code and take the > rcu_read_lock(). > > I'd say hold off on this and we'll fix it right. Same goes for the qib one. > > Alright, thank you for reviewing. > > The rdmavt one though looks to be OK. I'll give it a test. > > Hi, I just wanted to follow up on this. Any updates? Also, is the bug fixed now? Thank you, Madhuparna > Thank you, > Madhuparna > > -Denny >