Re: [PATCH 1/3] infiniband: hw: hfi1: verbs.c: Use built-in RCU list checking

[Dennis Dalessandro]

On 1/14/2020 11:57 AM, Jason Gunthorpe wrote:
> On Tue, Jan 14, 2020 at 09:53:45PM +0530, madhuparnabhowmik04@xxxxxxxxx wrote:
> > From: Madhuparna Bhowmik <madhuparnabhowmik04@xxxxxxxxx>
> >
> > 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 <madhuparnabhowmik04@xxxxxxxxx>
> >   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