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,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 4751FC433ED for ; Tue, 27 Apr 2021 20:49:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 26196613BC for ; Tue, 27 Apr 2021 20:49:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237055AbhD0Utw (ORCPT ); Tue, 27 Apr 2021 16:49:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54430 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239099AbhD0Uts (ORCPT ); Tue, 27 Apr 2021 16:49:48 -0400 Received: from mail-ed1-x529.google.com (mail-ed1-x529.google.com [IPv6:2a00:1450:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E9A8C061760 for ; Tue, 27 Apr 2021 13:49:04 -0700 (PDT) Received: by mail-ed1-x529.google.com with SMTP id s15so71619848edd.4 for ; Tue, 27 Apr 2021 13:49:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=GGoNFfJfVqo1Dt2wA+3xepQEKzGpUM+1CEyd/kxn9I4=; b=qEfkSh7MGE8PVxlqCWGjjSgsiEnsnVBnvrjRNNxqQEj5HU0k4aWay+siPtJdTOW5Xf zVOpXzCXY0HakOzD/zAOFn8Rvsn7R9MMypGaIbyqQ5mvyZd62oAMQzRju3r4ZZ6Dbh4Z PGwXTw7U7ke5bt4PusVhU/FjOe6PO8GyPwyQEOdOvEKEQO2whSN6EREZEHU4BumJ0tUN wYRqkBp8E0mktosAXmG+bLKjKBN+4yGMkELK1CaFKSqtKceOXNV5kbTOZ4Y9znDBNz7U OaKb8R39/BDxfS854M5MpP4bM8rl5sKWIpgUHtqb2i2Vtr8Gvv6JoSyU7i78Aj09c75j QnXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=GGoNFfJfVqo1Dt2wA+3xepQEKzGpUM+1CEyd/kxn9I4=; b=g/omApq9W5bkGKNA2cNJaAxEZunXQANlSqwcT3hridE0EBaBgJQbvvofBveslk1nJi 8BbXNG17dSdeaOnIJO0/k+JzFzjI1vLT8Ve1vTLzI6dIHnimsiLV9oTv9KDILU6Qf1mN 4h9HtNMmVPmPqCVBhzMrHK6aMFxVYXqIATUOhLG1nh+k1d6blrfQgyIVb11TB0RH3OYj one7u6Sw8mRiZrAFFrxL3UOU0nIH5TD6MyUnJT+/kf9R4KiDNFsLDLYDyaHmPuYGQGEU fL4x8hiq2ka5cL0UfY79slPjLaBIu06Yog8HwhqFcX1ofjNjJULm+N/LtYOyeyPIhGJZ h3xA== X-Gm-Message-State: AOAM531an65kwLyW3rMXGZyWoYbGH6oY42JRymgn1J/fIwLbtE/F6zpv 4HQ0ZRtkZA3FLyjt6CXbHiYBHwCZGqV9fTYiYL0dEQ== X-Google-Smtp-Source: ABdhPJyFMNunA2bOW/HTfw7I2Fxc07FXNBNlKOc55ZJx0surGmu20mPs7uTrsxToUeLXW66T1s7Gq8IAg4lX/ItiTU4= X-Received: by 2002:aa7:cd52:: with SMTP id v18mr6553464edw.97.1619556543314; Tue, 27 Apr 2021 13:49:03 -0700 (PDT) MIME-Version: 1.0 References: <20210408170123.8788-1-logang@deltatee.com> <20210427192838.GP2047089@ziepe.ca> <52f14602-94bc-fa98-0b97-5f4084d808a0@nvidia.com> In-Reply-To: <52f14602-94bc-fa98-0b97-5f4084d808a0@nvidia.com> From: Dan Williams Date: Tue, 27 Apr 2021 13:48:58 -0700 Message-ID: Subject: Re: [PATCH 00/16] Add new DMA mapping operation for P2PDMA To: John Hubbard Cc: Jason Gunthorpe , Logan Gunthorpe , linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, Stephen Bates , Christoph Hellwig , =?UTF-8?Q?Christian_K=C3=B6nig?= , Don Dutile , Matthew Wilcox , Daniel Vetter , Jakowski Andrzej , Minturn Dave B , Jason Ekstrand , Dave Hansen , Xiong Jianxin , Bjorn Helgaas , Ira Weiny , Robin Murphy Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Tue, Apr 27, 2021 at 1:22 PM John Hubbard wrote: > > On 4/27/21 12:28 PM, Jason Gunthorpe wrote: > > On Thu, Apr 08, 2021 at 11:01:07AM -0600, Logan Gunthorpe wrote: > >> Hi, > >> > >> This patchset continues my work to to add P2PDMA support to the common > >> dma map operations. This allows for creating SGLs that have both P2PDMA > >> and regular pages which is a necessary step to allowing P2PDMA pages in > >> userspace. > >> > >> The earlier RFC[1] generated a lot of great feedback and I heard no show > >> stopping objections. Thus, I've incorporated all the feedback and have > >> decided to post this as a proper patch series with hopes of eventually > >> getting it in mainline. > >> > >> I'm happy to do a few more passes if anyone has any further feedback > >> or better ideas. > > > > For the user of the DMA API the idea seems reasonable enough, the next > > steps to integrate with pin_user_pages() seem fairly straightfoward > > too > > > > Was there no feedback on this at all? > > > > oops, I meant to review this a lot sooner, because this whole p2pdma thing is > actually very interesting and important...somehow it slipped but I'll take > a look now. Still in my queue as well behind Joao's memmap consolidation series, and a recent copy_mc_to_iter() fix series from Al.