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Date: Mon, 4 Nov 2024 09:55:45 +0100
From: Christoph Hellwig <hch@lst.de>
To: Bart Van Assche <bvanassche@acm.org>
Cc: Leon Romanovsky <leon@kernel.org>, Jens Axboe <axboe@kernel.dk>,
	Jason Gunthorpe <jgg@ziepe.ca>, Robin Murphy <robin.murphy@arm.com>,
	Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
	Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>,
	Keith Busch <kbusch@kernel.org>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Logan Gunthorpe <logang@deltatee.com>,
	Yishai Hadas <yishaih@nvidia.com>,
	Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>,
	Kevin Tian <kevin.tian@intel.com>,
	Alex Williamson <alex.williamson@redhat.com>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	=?iso-8859-1?B?Suly9G1l?= Glisse <jglisse@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Jonathan Corbet <corbet@lwn.net>, linux-doc@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
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	linux-nvme@lists.infradead.org, linux-pci@vger.kernel.org,
	kvm@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [RFC PATCH 2/7] block: don't merge different kinds of P2P
 transfers in a single bio
Message-ID: <20241104085545.GB24211@lst.de>
References: <cover.1730037261.git.leon@kernel.org> <34d44537a65aba6ede215a8ad882aeee028b423a.1730037261.git.leon@kernel.org> <d4378502-6bc2-4064-8c35-191738105406@acm.org>
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User-Agent: Mutt/1.5.17 (2007-11-01)

On Thu, Oct 31, 2024 at 01:58:37PM -0700, Bart Van Assche wrote:
> On 10/27/24 7:21 AM, Leon Romanovsky wrote:
>> +		/*
>> +		 * When doing ZONE_DEVICE-based P2P transfers, all pages in a
>> +		 * bio must be P2P pages from the same device.
>> +		 */
>> +		if ((bio->bi_opf & REQ_P2PDMA) &&
>> +		    !zone_device_pages_have_same_pgmap(bv->bv_page, page))
>> +			return 0;
>
> It's probably too late to change the "zone_device_" prefix into
> something that cannot be confused with a reference to zoned block
> devices?

It's too late and also wrong and also entirely out of scope for this
series.