From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754521AbcFGMlL (ORCPT ); Tue, 7 Jun 2016 08:41:11 -0400 Received: from mail-wm0-f51.google.com ([74.125.82.51]:34477 "EHLO mail-wm0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753256AbcFGMlJ (ORCPT ); Tue, 7 Jun 2016 08:41:09 -0400 Subject: Re: [PATCH v2] IB/core: remove dead code To: Sudip Mukherjee , Doug Ledford , Sean Hefty , Hal Rosenstock References: <1465247706-4418-1-git-send-email-sudipm.mukherjee@gmail.com> Cc: linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, leon@kernel.org From: Sagi Grimberg Message-ID: <5756C0E0.7090303@lightbits.io> Date: Tue, 7 Jun 2016 15:41:04 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: <1465247706-4418-1-git-send-email-sudipm.mukherjee@gmail.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/06/16 00:15, Sudip Mukherjee wrote: > prot_sg_cnt has been assigned with the value of ret which we have > already checked to be non-zero so prot_sg_cnt can never be zero at this > point of the code and hence the else part can never execute. > And since we know prot_sg_cnt is non zero there is no use for the > if condition also. > > Signed-off-by: Sudip Mukherjee > --- > drivers/infiniband/core/rw.c | 24 ++++++++++-------------- > 1 file changed, 10 insertions(+), 14 deletions(-) > > diff --git a/drivers/infiniband/core/rw.c b/drivers/infiniband/core/rw.c > index 1eb9b12..a829a14 100644 > --- a/drivers/infiniband/core/rw.c > +++ b/drivers/infiniband/core/rw.c > @@ -386,21 +386,17 @@ int rdma_rw_ctx_signature_init(struct rdma_rw_ctx *ctx, struct ib_qp *qp, > count += ret; > prev_wr = &ctx->sig->data.reg_wr.wr; > > - if (prot_sg_cnt) { > - ret = rdma_rw_init_one_mr(qp, port_num, &ctx->sig->prot, > - prot_sg, prot_sg_cnt, 0); > - if (ret < 0) > - goto out_destroy_data_mr; > - count += ret; > + ret = rdma_rw_init_one_mr(qp, port_num, &ctx->sig->prot, > + prot_sg, prot_sg_cnt, 0); > + if (ret < 0) > + goto out_destroy_data_mr; > + count += ret; > > - if (ctx->sig->prot.inv_wr.next) > - prev_wr->next = &ctx->sig->prot.inv_wr; > - else > - prev_wr->next = &ctx->sig->prot.reg_wr.wr; > - prev_wr = &ctx->sig->prot.reg_wr.wr; > - } else { > - ctx->sig->prot.mr = NULL; > - } > + if (ctx->sig->prot.inv_wr.next) > + prev_wr->next = &ctx->sig->prot.inv_wr; > + else > + prev_wr->next = &ctx->sig->prot.reg_wr.wr; > + prev_wr = &ctx->sig->prot.reg_wr.wr; > > ctx->sig->sig_mr = ib_mr_pool_get(qp, &qp->sig_mrs); > if (!ctx->sig->sig_mr) { > Actually it looks like the data-integrity insert/strip operation (where protection sg list does not exist) is broken. It looks that the protection scatterlist should be done only if prot_sg_count was provided... I don't have access to mlx5 devices at the moment (still waiting to get some...)