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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 AFDE8C433B4 for ; Wed, 19 May 2021 15:32:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 89D4F611AB for ; Wed, 19 May 2021 15:32:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354940AbhESPeH (ORCPT ); Wed, 19 May 2021 11:34:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:56318 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354936AbhESPeG (ORCPT ); Wed, 19 May 2021 11:34:06 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7BBDE611AD; Wed, 19 May 2021 15:32:45 +0000 (UTC) Date: Wed, 19 May 2021 18:32:42 +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> <7a66efb0-7195-aed1-7085-02374028f079@acm.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7a66efb0-7195-aed1-7085-02374028f079@acm.org> Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Wed, May 19, 2021 at 08:13:09AM -0700, Bart Van Assche wrote: > On 5/19/21 2:09 AM, Leon Romanovsky wrote: > > On Tue, May 11, 2021 at 08:27:52PM -0700, Bart Van Assche wrote: > >> -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 > > Hi Leon, > > I think that per-request private data is zero-initialized and hence that > it is not necessary to clear req->fr_list explicitly. blk_mq_alloc_rqs() > passes __GFP_ZERO to alloc_pages_node(). blk_mq_alloc_rqs() does not > only allocate block layer requests (struct request) but also per-request > private data (set->cmd_size). So you don't need this "if (dev->use_fast_reg)" check. Thanks > > Thanks, > > Bart. > >