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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_MED 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 10A8DC433F4 for ; Thu, 30 Aug 2018 19:11:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A957C20835 for ; Thu, 30 Aug 2018 19:11:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="V+Sm+tjU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A957C20835 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727240AbeH3XPB (ORCPT ); Thu, 30 Aug 2018 19:15:01 -0400 Received: from mail-it0-f43.google.com ([209.85.214.43]:55054 "EHLO mail-it0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727117AbeH3XPB (ORCPT ); Thu, 30 Aug 2018 19:15:01 -0400 Received: by mail-it0-f43.google.com with SMTP id f14-v6so4055220ita.4 for ; Thu, 30 Aug 2018 12:11:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=g7v8KVcLqnDf+9fgon1CPhLtcLM3PxMlyVE5fEOaYy8=; b=V+Sm+tjU4jJvxkGil6YXxVdlrRSp9QEl9ThCk6xJOptUlf7rcKWJ7QywM9/+d6lgg9 Cv2bMEuuW6zPwi6zn1dRmYpPY/sXubUICzIBxrBKZNy2uuJsAdBSqhYUNdgNy6MTdCeu gRnHOW+Jl2J0ClRNlgGwt5L/HlQoSXMvnFGOa7eeTAWMKuvtPO8XPr0HpxMlw4CK7lvu 7z7qXzGLMtBUYqMJsy6wSElWea9uf1LnMHM3GhlusIPLLXdVEL/UzY2JYrMltm7Sc0X1 tZETb3g76uK7wTQj+fcjWY1NqVNJ1qBu+9hpsS3TCFFMUOybny97iVbmMbI2NKz5KnzV pr1g== 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=g7v8KVcLqnDf+9fgon1CPhLtcLM3PxMlyVE5fEOaYy8=; b=YULVnO/FOkVH++LE86Rvl4u1m4W61SOI0dcDCWoPpzgvYxwxttAek0rVi/60Cxcc2c p0xYivPK2Dxjt4qy0iOxbL0ld7aWUHrg7XEsn8RhO0lgTqfnNp+l2yVPBmRke6ndAEI6 Jm8QZ3qKm6GtfzVcVAqqUvFLOTJhOR3CTVecdktBtIw6zQftQs6TQZgVTFcelRFDxJWx uLNWrbKpxrltJ5g4vhEHLQDA+tXBNqRbeNwnQp5GqcWvAWmpOVSiFWWEKIHv/JmpUkG+ bjMsoQVutsT987b5nzDo2U6jK/AaJAEBddoVt3b502HznGeJZsB4J5KlWBzM4269s+0P Oxsg== X-Gm-Message-State: APzg51DIO0fW0/AjAy4vRvlVTEu+5aQlJsEg2+PgV8kC8oCe2QHzaPpv kd0MbKuK4GyNqEB/y8u7MVtGAw== X-Google-Smtp-Source: ANB0Vda0Exfhiz84XQu61c86kGqnTxHSzBX9wkNI8HaU9Ht+W9qzUsiL+NZEHukB1XbFEi31AjAscA== X-Received: by 2002:a24:9d84:: with SMTP id f126-v6mr3258556itd.130.1535656281718; Thu, 30 Aug 2018 12:11:21 -0700 (PDT) Received: from [192.168.1.56] ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id w20-v6sm3281113ioa.82.2018.08.30.12.11.19 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 30 Aug 2018 12:11:20 -0700 (PDT) Subject: Re: [PATCH v5 07/13] block: Add PCI P2P flag for request queue and check support for requests To: Logan Gunthorpe , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-nvme@lists.infradead.org, linux-rdma@vger.kernel.org, linux-nvdimm@lists.01.org, linux-block@vger.kernel.org Cc: Stephen Bates , Christoph Hellwig , Keith Busch , Sagi Grimberg , Bjorn Helgaas , Jason Gunthorpe , Max Gurtovoy , Dan Williams , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Benjamin Herrenschmidt , Alex Williamson , =?UTF-8?Q?Christian_K=c3=b6nig?= References: <20180830185352.3369-1-logang@deltatee.com> <20180830185352.3369-8-logang@deltatee.com> From: Jens Axboe Message-ID: Date: Thu, 30 Aug 2018 13:11:18 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.0 MIME-Version: 1.0 In-Reply-To: <20180830185352.3369-8-logang@deltatee.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/30/18 12:53 PM, Logan Gunthorpe wrote: > QUEUE_FLAG_PCI_P2P is introduced meaning a driver's request queue > supports targeting P2P memory. > > When a request is submitted we check if PCI P2PDMA memory is assigned > to the first page in the bio. If it is, we ensure the queue it's > submitted to supports it, and enforce REQ_NOMERGE. I think this belongs in the caller - both the validity check, and passing in NOMERGE for this type of request. I don't want to impose this overhead on everything, for a pretty niche case. -- Jens Axboe