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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A4902C54E58 for ; Thu, 21 Mar 2024 08:03:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=4FQ4qNojKHxYbM+mjcMGc+v03sD6jBJ9rR92BjQFE/k=; b=WCZUDEkdXaByhHq4LPJ8Yj4/5t 3a/Ur8FR+on0NZBsTKZdc5vj4HfEKxnis8Dq6xMfE0Va9xyTirNGT9Cbjb8edWYlHo+xnL44mrR8T Jg56HTCUwR3XNtoznMyumleA23ivZqlyKUMRSzH7Koi3FDEEIkGEJr/3UPzJKU1D5EykhX8/vcA7O EEdy46FKbOJeDWZWL8lAMN6cnb531U3f6/OtTcmYukhJXZmmFBuUQ3WH25TfBrwouahfsDkfmPP7a 79JWtSf/eXMPRxeUS18c13UgNNmdN+pliMO7e0yIYHs5js0SUO6OREEyWH+W4o7lkxwFXkN21UcCN 1oQzIDSw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rnDOj-00000002EY0-1S9i; Thu, 21 Mar 2024 08:03:37 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rkWOd-0000000ByVc-3dIs for linux-nvme@lists.infradead.org; Wed, 13 Mar 2024 21:44:25 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 8161568BFE; Wed, 13 Mar 2024 22:44:18 +0100 (CET) Date: Wed, 13 Mar 2024 22:44:18 +0100 From: Christoph Hellwig To: Leon Romanovsky Cc: Christoph Hellwig , Jason Gunthorpe , Robin Murphy , Marek Szyprowski , Joerg Roedel , Will Deacon , Chaitanya Kulkarni , Jonathan Corbet , Jens Axboe , Keith Busch , Sagi Grimberg , Yishai Hadas , Shameer Kolothum , Kevin Tian , Alex Williamson , =?iso-8859-1?B?Suly9G1l?= Glisse , Andrew Morton , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-rdma@vger.kernel.org, iommu@lists.linux.dev, linux-nvme@lists.infradead.org, kvm@vger.kernel.org, linux-mm@kvack.org, Bart Van Assche , Damien Le Moal , Amir Goldstein , "josef@toxicpanda.com" , "Martin K. Petersen" , "daniel@iogearbox.net" , Dan Williams , "jack@suse.com" , Zhu Yanjun Subject: Re: [RFC RESEND 00/16] Split IOMMU DMA mapping operation to two steps Message-ID: <20240313214418.GA9129@lst.de> References: <20240306221400.GA8663@lst.de> <20240307000036.GP9225@ziepe.ca> <20240307150505.GA28978@lst.de> <20240307210116.GQ9225@ziepe.ca> <20240308164920.GA17991@lst.de> <20240308202342.GZ9225@ziepe.ca> <20240309161418.GA27113@lst.de> <20240310093513.GB12921@unreal> <20240312212844.GA3018@lst.de> <20240313074636.GV12921@unreal> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240313074636.GV12921@unreal> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240313_144424_197473_BE40E6F1 X-CRM114-Status: GOOD ( 18.52 ) X-Mailman-Approved-At: Thu, 21 Mar 2024 01:03:35 -0700 X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Wed, Mar 13, 2024 at 09:46:36AM +0200, Leon Romanovsky wrote: > On Tue, Mar 12, 2024 at 10:28:44PM +0100, Christoph Hellwig wrote: > > On Sun, Mar 10, 2024 at 11:35:13AM +0200, Leon Romanovsky wrote: > > > And you will need to have a way to instruct that pin_user_pages() variant > > > to continue anyway, because you asked for FOLL_PCI_P2PDMA. Without that > > > force, you will have !FOLL_PCI_P2PDMA behaviour. > > > > I don't understand what you mean. > > Jason talked about the need to call to pin_user_pages(..., gup_flags | FOLL_PCI_P2PDMA, ...), > but in your proposal this call won't be possible anymore. Why?