From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A84FAC433B4 for ; Wed, 19 May 2021 09:10:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8592361363 for ; Wed, 19 May 2021 09:10:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343713AbhESJMJ (ORCPT ); Wed, 19 May 2021 05:12:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:42332 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344703AbhESJLF (ORCPT ); Wed, 19 May 2021 05:11:05 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 27634611AE; Wed, 19 May 2021 09:09:44 +0000 (UTC) Date: Wed, 19 May 2021 12:09:41 +0300 From: Leon Romanovsky To: Bart Van Assche Cc: Jason Gunthorpe , Doug Ledford , linux-rdma@vger.kernel.org, Nicolas Morey-Chaisemartin Subject: Re: [PATCH 5/5] RDMA/srp: Make struct scsi_cmnd and struct srp_request adjacent Message-ID: References: <20210512032752.16611-1-bvanassche@acm.org> <20210512032752.16611-6-bvanassche@acm.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210512032752.16611-6-bvanassche@acm.org> Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Tue, May 11, 2021 at 08:27:52PM -0700, Bart Van Assche wrote: > Define .init_cmd_priv and .exit_cmd_priv callback functions in struct > scsi_host_template. Set .cmd_size such that the SCSI core allocates > per-command private data. Use scsi_cmd_priv() to access that private > data. Remove the req_ring pointer from struct srp_rdma_ch since it is > no longer necessary. Convert srp_alloc_req_data() and srp_free_req_data() > into functions that initialize one instance of the SRP-private command > data. This is a micro-optimization since this patch removes several > pointer dereferences from the hot path. > > Note: due to commit e73a5e8e8003 ("scsi: core: Only return started requests > from scsi_host_find_tag()"), it is no longer necessary to protect the > completion path against duplicate responses. > > Cc: Nicolas Morey-Chaisemartin > Signed-off-by: Bart Van Assche > --- > drivers/infiniband/ulp/srp/ib_srp.c | 156 ++++++++++++---------------- > drivers/infiniband/ulp/srp/ib_srp.h | 2 - > 2 files changed, 65 insertions(+), 93 deletions(-) > > diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c > index 52db42af421b..773ac5929082 100644 > --- a/drivers/infiniband/ulp/srp/ib_srp.c > +++ b/drivers/infiniband/ulp/srp/ib_srp.c > @@ -965,69 +965,55 @@ static void srp_disconnect_target(struct srp_target_port *target) > } > } > > -static void srp_free_req_data(struct srp_target_port *target, > - struct srp_rdma_ch *ch) > +static int srp_exit_cmd_priv(struct Scsi_Host *shost, struct scsi_cmnd *cmd) > { > + struct srp_target_port *target = host_to_target(shost); > struct srp_device *dev = target->srp_host->srp_dev; > struct ib_device *ibdev = dev->dev; > - struct srp_request *req; > - int i; > + struct srp_request *req = scsi_cmd_priv(cmd); > > - if (!ch->req_ring) > - return; > - > - for (i = 0; i < target->req_ring_size; ++i) { > - req = &ch->req_ring[i]; > - if (dev->use_fast_reg) > - kfree(req->fr_list); > - if (req->indirect_dma_addr) { > - ib_dma_unmap_single(ibdev, req->indirect_dma_addr, > - target->indirect_size, > - DMA_TO_DEVICE); > - } > - kfree(req->indirect_desc); > + if (dev->use_fast_reg) > + kfree(req->fr_list); Isn't cleaner will be to ensure that fr_list is NULL for !dev->use_fast_reg path? In patch #4 https://lore.kernel.org/linux-rdma/20210512032752.16611-5-bvanassche@acm.org Thanks