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

From: Jason Gunthorpe
Date: Tue Jan 14 2020 - 11:57:44 EST


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?

Jason