> On Jul 18, 2018, at 12:25 PM, Bart Van Assche <Bart.VanAssche@xxxxxxx> wrote:
>
> Instead of declaring and passing a dummy 'bad_wr' pointer, pass NULL
> as third argument to ib_post_(send|recv|srq_recv)().
>
> Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
> Cc: Chuck Lever <chuck.lever@xxxxxxxxxx>
I guess the theory is that since ib_post_{send,recv} are declared static inline,
the compiler can see that the third argument is a constant NULL and optimize
away the conditional "bad_recv_wr ? : &dummy" at each call site.
Reviewed-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
> ---
> net/sunrpc/xprtrdma/fmr_ops.c | 4 +---
> net/sunrpc/xprtrdma/frwr_ops.c | 4 ++--
> net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 3 +--
> net/sunrpc/xprtrdma/svc_rdma_rw.c | 2 +-
> net/sunrpc/xprtrdma/svc_rdma_sendto.c | 3 +--
> 5 files changed, 6 insertions(+), 10 deletions(-)
>
> diff --git a/net/sunrpc/xprtrdma/fmr_ops.c b/net/sunrpc/xprtrdma/fmr_ops.c
> index 17fb1e025654..0f7c465d9a5a 100644
> --- a/net/sunrpc/xprtrdma/fmr_ops.c
> +++ b/net/sunrpc/xprtrdma/fmr_ops.c
> @@ -279,9 +279,7 @@ fmr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
> static int
> fmr_op_send(struct rpcrdma_ia *ia, struct rpcrdma_req *req)
> {
> - struct ib_send_wr *bad_wr;
> -
> - return ib_post_send(ia->ri_id->qp, &req->rl_sendctx->sc_wr, &bad_wr);
> + return ib_post_send(ia->ri_id->qp, &req->rl_sendctx->sc_wr, NULL);
> }
>
> /* Invalidate all memory regions that were registered for "req".
> diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c
> index c040de196e13..a167eebf63d5 100644
> --- a/net/sunrpc/xprtrdma/frwr_ops.c
> +++ b/net/sunrpc/xprtrdma/frwr_ops.c
> @@ -464,7 +464,7 @@ frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
> static int
> frwr_op_send(struct rpcrdma_ia *ia, struct rpcrdma_req *req)
> {
> - struct ib_send_wr *post_wr, *bad_wr;
> + struct ib_send_wr *post_wr;
> struct rpcrdma_mr *mr;
>
> post_wr = &req->rl_sendctx->sc_wr;
> @@ -486,7 +486,7 @@ frwr_op_send(struct rpcrdma_ia *ia, struct rpcrdma_req *req)
> /* If ib_post_send fails, the next ->send_request for
> * @req will queue these MWs for recovery.
> */
> - return ib_post_send(ia->ri_id->qp, post_wr, &bad_wr);
> + return ib_post_send(ia->ri_id->qp, post_wr, NULL);
> }
>
> /* Handle a remotely invalidated mr on the @mrs list
> diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
> index 841fca143804..2ef75e885411 100644
> --- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
> +++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
> @@ -229,11 +229,10 @@ void svc_rdma_recv_ctxt_put(struct svcxprt_rdma *rdma,
> static int __svc_rdma_post_recv(struct svcxprt_rdma *rdma,
> struct svc_rdma_recv_ctxt *ctxt)
> {
> - struct ib_recv_wr *bad_recv_wr;
> int ret;
>
> svc_xprt_get(&rdma->sc_xprt);
> - ret = ib_post_recv(rdma->sc_qp, &ctxt->rc_recv_wr, &bad_recv_wr);
> + ret = ib_post_recv(rdma->sc_qp, &ctxt->rc_recv_wr, NULL);
> trace_svcrdma_post_recv(&ctxt->rc_recv_wr, ret);
> if (ret)
> goto err_post;
> diff --git a/net/sunrpc/xprtrdma/svc_rdma_rw.c b/net/sunrpc/xprtrdma/svc_rdma_rw.c
> index ce3ea8419704..80975427f523 100644
> --- a/net/sunrpc/xprtrdma/svc_rdma_rw.c
> +++ b/net/sunrpc/xprtrdma/svc_rdma_rw.c
> @@ -329,7 +329,7 @@ static int svc_rdma_post_chunk_ctxt(struct svc_rdma_chunk_ctxt *cc)
> do {
> if (atomic_sub_return(cc->cc_sqecount,
> &rdma->sc_sq_avail) > 0) {
> - ret = ib_post_send(rdma->sc_qp, first_wr, &bad_wr);
> + ret = ib_post_send(rdma->sc_qp, first_wr, NULL);
> trace_svcrdma_post_rw(&cc->cc_cqe,
> cc->cc_sqecount, ret);
> if (ret)
> diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
> index 4a3efaea277c..ffef0c508f1a 100644
> --- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c
> +++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
> @@ -291,7 +291,6 @@ static void svc_rdma_wc_send(struct ib_cq *cq, struct ib_wc *wc)
> */
> int svc_rdma_send(struct svcxprt_rdma *rdma, struct ib_send_wr *wr)
> {
> - struct ib_send_wr *bad_wr;
> int ret;
>
> might_sleep();
> @@ -311,7 +310,7 @@ int svc_rdma_send(struct svcxprt_rdma *rdma, struct ib_send_wr *wr)
> }
>
> svc_xprt_get(&rdma->sc_xprt);
> - ret = ib_post_send(rdma->sc_qp, wr, &bad_wr);
> + ret = ib_post_send(rdma->sc_qp, wr, NULL);
> trace_svcrdma_post_send(wr, ret);
> if (ret) {
> set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags);
> --
> 2.18.0
>
> --
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--
Chuck Lever
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