On Tue, Jul 18, 2023 at 12:59:43PM -0500, Bob Pearson wrote:
> This patch allows drivers to optionally include struct rcu_head
> in their private object data structs and have rdma-core use kfree_rcu
> to free the objects.
>
> The offsets of the rcu_heads are stored in fields in struct
> ib_device_ops and a macro RDMA_KFREE_RCU is introduced which calls
> (an open coded) kfree_rcu instead of kfree if the value is non-
> zero. Currently the supported object types are AH, QP and MW.
>
> Signed-off-by: Bob Pearson <rpearsonhpe@xxxxxxxxx>
> ---
> drivers/infiniband/core/uverbs_main.c | 2 +-
> drivers/infiniband/core/verbs.c | 6 +++---
> include/rdma/ib_verbs.h | 24 ++++++++++++++++++++++++
> 3 files changed, 28 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
> index 7c9c79c13941..50497e550f18 100644
> --- a/drivers/infiniband/core/uverbs_main.c
> +++ b/drivers/infiniband/core/uverbs_main.c
> @@ -112,7 +112,7 @@ int uverbs_dealloc_mw(struct ib_mw *mw)
> return ret;
>
> atomic_dec(&pd->usecnt);
> - kfree(mw);
> + RDMA_KFREE_RCU(mw);
> return ret;
> }
>
> diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c
> index b99b3cc283b6..a49ae8c52c66 100644
> --- a/drivers/infiniband/core/verbs.c
> +++ b/drivers/infiniband/core/verbs.c
> @@ -982,7 +982,7 @@ int rdma_destroy_ah_user(struct ib_ah *ah, u32 flags, struct ib_udata *udata)
> if (sgid_attr)
> rdma_put_gid_attr(sgid_attr);
>
> - kfree(ah);
> + RDMA_KFREE_RCU(ah);
> return ret;
> }
> EXPORT_SYMBOL(rdma_destroy_ah_user);
> @@ -1970,7 +1970,7 @@ int ib_close_qp(struct ib_qp *qp)
> atomic_dec(&real_qp->usecnt);
> if (qp->qp_sec)
> ib_close_shared_qp_security(qp->qp_sec);
> - kfree(qp);
> + RDMA_KFREE_RCU(qp);
>
> return 0;
> }
> @@ -2041,7 +2041,7 @@ int ib_destroy_qp_user(struct ib_qp *qp, struct ib_udata *udata)
> ib_destroy_qp_security_end(sec);
>
> rdma_restrack_del(&qp->res);
> - kfree(qp);
> + RDMA_KFREE_RCU(qp);
> return ret;
> }
> EXPORT_SYMBOL(ib_destroy_qp_user);
> diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
> index 1e7774ac808f..616e9e54a733 100644
> --- a/include/rdma/ib_verbs.h
> +++ b/include/rdma/ib_verbs.h
> @@ -2684,8 +2684,32 @@ struct ib_device_ops {
> DECLARE_RDMA_OBJ_SIZE(ib_srq);
> DECLARE_RDMA_OBJ_SIZE(ib_ucontext);
> DECLARE_RDMA_OBJ_SIZE(ib_xrcd);
> +
> + /* if non-zero holds offset of rcu_head in object */
> + ssize_t rcu_offset_ah;
> + ssize_t rcu_offset_qp;
> + ssize_t rcu_offset_mw;
Just size_t, this isn't negative
> +static inline void __rdma_kfree_rcu(void *obj, ssize_t rcu_offset)
Here too
Jason
