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[209.132.180.67]) by mx.google.com with ESMTP id p21-v6si2561513plq.338.2018.09.05.13.21.39; Wed, 05 Sep 2018 13:21:55 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel-dk.20150623.gappssmtp.com header.s=20150623 header.b=uKNMms6J; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727976AbeIFAva (ORCPT + 99 others); Wed, 5 Sep 2018 20:51:30 -0400 Received: from mail-it0-f46.google.com ([209.85.214.46]:36310 "EHLO mail-it0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727586AbeIFAva (ORCPT ); Wed, 5 Sep 2018 20:51:30 -0400 Received: by mail-it0-f46.google.com with SMTP id u13-v6so11211708iti.1 for ; Wed, 05 Sep 2018 13:19:42 -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=I2A46jX71yroumZdLirx89tBYPtjvNrtZpAe6pwPsIw=; b=uKNMms6JWhE33FlQRWls0EgRXlbMKZhk+/WMR/5xDPUIs3rNAH1Dg6VPV4/QVRI2L+ O7pqwoyEFNLl94EjrLN9REKWPvRmxJluaPTaQLa3FAaLVzjwkbn0uHQ05e/M0SLc2uNS VSxTXl/bMVlVmzm2/etVXutbedoT/+a3HZFFtCykXIrTkr6EzVP7jszwJT5gZeFWKve1 JHZYvmhLRw+IaSqhrKGQ8xrpvZckCLRi17rGwY+3+YMSe2oG1scJOpahwqtnkotLaGq1 iIKjLaR+Oa8DpqCVSFDqk2RLlEHoLZ2I4ZgQtzt+p301HQGeNOlJH3RoUlmTsjgaZIeQ 0XZg== 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=I2A46jX71yroumZdLirx89tBYPtjvNrtZpAe6pwPsIw=; b=WxW0u1VsN/fOAvMZeBRQ3PqSdDDK839CwlEAHng7Zh0SjwYRn/aFKZOY8nFxGrYwey +8OTFa2n7ZnNtYYc6Lj39+ND5hhHdNZyW1kldkdQ9hbu0s/Lasoc8Vq0N0o7VImlhB8G 8jW4s/OujNS+Z6PYzsKuDnzOX4mibjUGEktJ+MDLplwzOAXXjNGu2gaRYbkLssJ+pNvD xISGKJWqnl3AiPtRbJ2egdKxGwGqqWWAq/9KkIJbcW1ozLj1/WdIU60T2omMxKsEXUpl v1em4JQveq8A7C0rRzFQpmML+QekdHqOCka5PdFQbNL7tGDcF9VZusjiXAvwL+7Cx0Yy 5zOw== X-Gm-Message-State: APzg51CjKs9qrfuYCp+a4STPnACCygqTdGsiUwB40b6Itbx2XQi9fXsE t9VKFXuhBQCfthrn0sjTKCjwpQ== X-Received: by 2002:a24:4c90:: with SMTP id a138-v6mr48194itb.138.1536178782002; Wed, 05 Sep 2018 13:19:42 -0700 (PDT) Received: from [192.168.1.56] ([216.160.245.98]) by smtp.gmail.com with ESMTPSA id e129-v6sm1371708ite.35.2018.09.05.13.19.39 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 05 Sep 2018 13:19:40 -0700 (PDT) Subject: Re: [PATCH v5 07/13] block: Add PCI P2P flag for request queue and check support for requests To: Logan Gunthorpe , Christoph Hellwig Cc: 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, Stephen Bates , 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> <20180901082812.GB670@lst.de> <5f79c012-c6e1-56bb-62fd-0689181fb2c9@deltatee.com> <59b28977-8f2a-6228-2050-03fae6bdbedd@kernel.dk> <1b4283da-44df-4a02-3167-e295243cef78@deltatee.com> <09258b9b-3aed-9890-b31a-bd70a133966c@kernel.dk> <20180905195647.GA1626@lst.de> <20180905201152.GA1893@lst.de> <2a3394bd-5f13-4818-43f4-dfc61f501e05@kernel.dk> From: Jens Axboe Message-ID: <3af4d1d4-da07-c0a6-8464-9ddc1378f2f4@kernel.dk> Date: Wed, 5 Sep 2018 14:19:39 -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: 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 9/5/18 2:18 PM, Logan Gunthorpe wrote: > > > On 05/09/18 02:14 PM, Jens Axboe wrote: >> But if the caller must absolutely know where the bio will end up, then >> it seems super redundant. So I'd vote for killing this check, it buys >> us absolutely nothing and isn't even exhaustive in its current form. > > > Ok, I'll remove it for v6. Since the drivers needs to know it's doing it right, it might not hurt to add a sanity check helper for that. Just have the driver call it, and don't add it in the normal IO submission path. -- Jens Axboe