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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 32B7DC433ED for ; Wed, 19 May 2021 15:13:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 166B861007 for ; Wed, 19 May 2021 15:13:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233672AbhESPOc (ORCPT ); Wed, 19 May 2021 11:14:32 -0400 Received: from mail-pl1-f177.google.com ([209.85.214.177]:36374 "EHLO mail-pl1-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233577AbhESPOc (ORCPT ); Wed, 19 May 2021 11:14:32 -0400 Received: by mail-pl1-f177.google.com with SMTP id a11so7213900plh.3 for ; Wed, 19 May 2021 08:13:13 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=YwBW+98p32ERsG+4hfWJ0+sbVFdVPcYWgtfWFWHjbx4=; b=CaBQyckQA/snYSulPburkdweZiZVTYEGL6To5QcWjbW5q15dVT4HjrVREVZmq2k6mp JZcs9DRdmkniqhspo3Y7GsjZSxnXEEteaoDYq7UphfRNBl3aI/QWVgDU/l2DDFXY0INk wxvrl7kzkBBlcEAsktOKzm6GTlVC0LJcgu4KccX1B/Zfx8qnJP4gyTs/bJsEGdD/6c4L FE4cHNyeZPGpwRvYR1SZb6KHEecdI++CdzR4TUFS7zRwg/ObsakdB1lhLb16iMyPwtxj Aq1wxMVzGyrEXTCv3LUdFzq2qZ3cR313HjmplnmszVY5BqPACAvzzyyrP9/vWYRXXbg5 zMrQ== X-Gm-Message-State: AOAM5317KP/LRdK8FPz+kuWLRLb+RtNoPpMbK9UWVI49vaBmkjzYf9EA zFyivx9h5V5j62bxRZGuOxs= X-Google-Smtp-Source: ABdhPJySBAa9B5exJckvfJE0HYPKKKxMLYcJZn5xVbbofKbu72pPf1CPI9LuSbqv+MSUr3FM425Hvg== X-Received: by 2002:a17:902:bcc7:b029:ed:6f73:ffc4 with SMTP id o7-20020a170902bcc7b02900ed6f73ffc4mr11429054pls.1.1621437192265; Wed, 19 May 2021 08:13:12 -0700 (PDT) Received: from ?IPv6:2601:647:4000:d7:db5a:2bf3:3617:be1c? ([2601:647:4000:d7:db5a:2bf3:3617:be1c]) by smtp.gmail.com with ESMTPSA id a16sm14598466pfc.37.2021.05.19.08.13.10 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 19 May 2021 08:13:11 -0700 (PDT) Subject: Re: [PATCH 5/5] RDMA/srp: Make struct scsi_cmnd and struct srp_request adjacent To: Leon Romanovsky Cc: Jason Gunthorpe , Doug Ledford , linux-rdma@vger.kernel.org, Nicolas Morey-Chaisemartin References: <20210512032752.16611-1-bvanassche@acm.org> <20210512032752.16611-6-bvanassche@acm.org> From: Bart Van Assche Message-ID: <7a66efb0-7195-aed1-7085-02374028f079@acm.org> Date: Wed, 19 May 2021 08:13:09 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org 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). Thanks, Bart.