From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed2-f12.google.com (mail-ed2-f12.google.com [74.125.228.76]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6C96D54855D for ; Tue, 22 Sep 2026 13:37:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.228.76 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790084239; cv=none; b=KQ56eSpwcGrKQFrBcVbBAsq1mW1FxF4ghDul4jTzvNS8oYc9cKpEEjxAAcmHzC2p2JPlxm1yTvBz051Z3cgz4Nn5ibZHhHrBVyDFKSoH+Ljb5wDd2BimsRycYNS1od9OzsTugiMRXN0uFHPdNot27HwGsQFVSYlP3JiepcGtZcI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790084239; c=relaxed/simple; bh=HQWVBZQ3a3dF/DEyKoutDX9guSe4Idp8wVDepJLrORk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=jb6ASFiTbAa3WVRx5pCU9L55ggaupsl1nInOq2upA5XZo4N4FQHlmv+kLMmjxd7pcNUcP4L7VwgAm4/Ev+8oSJjH8Qj+r4pI+QBXSpgT38YPj1cJT1lAOL3ZCNhKIzXAlL1/rQKqMDQfpdeq23fnQILamu2Mv4pseX+J3OE5eqE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Y9bkKHtw; arc=none smtp.client-ip=74.125.228.76 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Y9bkKHtw" Received: by mail-ed2-f12.google.com with SMTP id 4fb4d7f45d1cf-6a60590a85cso7818114a12.0 for ; Tue, 22 Sep 2026 06:37:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1790084236; x=1790689036; darn=vger.kernel.org; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to :content-type; bh=3SSB6/4UTXtVP9h0KYT7VpnYQgkILrKgn1VnZQd7YA4=; b=Y9bkKHtw4enwyqHTeubDc/hx54OJBxkeUi0FqlJAnpEf91s27PXl+tasxyNLFbyoYC jXUWVQ9sCr+9/vROmsNXwRmAPdfxZ4OVE0PwaoEwT/ZD28DT1Ajfppy+TwEwPDpTJ5Wd 8cHthTZQGvZl6HjcGPRhluw6PreSdfWmx90Epw+BhOD08wxmnBhFSvLNDefwhuD/a9LO RPe57iVuZNtHqtFh8yPsPEO/Y6CvsN96wnniPDAlT9eaIGd7gSUsPbL/aHTrif98/2Fr LL64vsXgF32RaTvf8BVtlGYT6IkRsiRBD4EsCr77NQzcoP8C7xS+XR639uPQ/73UojlP hUuA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790084236; x=1790689036; h=content-transfer-encoding:content-type:in-reply-to:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=3SSB6/4UTXtVP9h0KYT7VpnYQgkILrKgn1VnZQd7YA4=; b=G7ZEhI48VcVmL+FNGAjtZxdNT8ugQ5NiIfkZapFOquqL8lfUVOiXvq8HBcT/BGXMUR iCP8UNfL7ebgIXARLGgvI9vBh3ZtKrdyRfhx3pCMNJNUHDD4aJWozpjpbo9+0uSRJNK3 o7xVkkan135AZPMaFaN3fYz+77qQ8n9p6X43L3aE9goQqayXbbIlB9LChcGckt29feO0 bUdL+N+XgGQpg4xjPNr+LWycBb/OXghsQy7fLvFPWF9e4fNZSZ3fNbeLoSuS9PhfnyLJ L/EwpMjcVGiw0ULO7M2cy9kAbI46xmOnSvxhMJ2CI7oBnxSL4/3GicS3GBmlLGsPRpq2 nyDg== X-Forwarded-Encrypted: i=1; AKwUvBx1lFF/VNKBfB636UzMqIGtHsv7j/rKw4RfnUv2PcmzEbJvi9ggAK/nuVhvMUwH8f4+2ferRJtU7w==@vger.kernel.org X-Gm-Message-State: AFuF++n/U1oKbt5h8t1GTgYI3n0deCzVu6gyq/JGUScDnpS978nrBi/r z8T7me7iGfY5FgGYzwRMXNfi+lWNO5I4hwvc+6eExrCsxFelD33bm/1B X-Gm-Gg: AYBFou2NA7tRbI/38xnJlKGvnvj8fNSP4wOHgwz4R5x4MI6j3k0kqg7AwzHn/D1yvEg cTs7FtjKK8w4Pr+2ivm40fnLeVucx7Hc/e4uMPNEfVBBfZaTQJYTVVI7echkUySkC5Q9cdFOoyf LDVxYBxKd1sJ4yK5fXqjaTUN4ZmFBkwPKnfp+SDFc0iAnzD8J9ymRq5e28TzUNiO0ZkL6bBD5mE tXwECl6Uc3kasSYVWvVz72pM0n9mvV+Rdoy7s7BVWZ4T2RbSSv4/Vg9SarDQAPy2dTOo3/ZWSyv XlWAiowSo+gSGRIWBuSBlw3Qoab7Xa/a2USQrUsVjJQOfhfS0M7SQwqG24y6oIpIHQ4aTJ3WbuP WGoGn2qY1FhnoRPCjQkVVawzpvj8l0PTbfVk5Qu4dM5WuorSril3KmEEfe0ktW8wb/3QY7C6aX6 XSDXDfnz8Jg4Vek5xeDXvAaRuH8uaA+ttZyTPJYD1h3+2zzx8rrQeceUtS8u5w8ENj60BFNTe1W Got5vk/KZthNnzcVe8npspJFvh/68bLOuIb0lHia08yJtoEle8bMhPb5dT4vpfdDuVx9VxBuM0/ 9bHm7NUg4KaM9FxGaB9dvae3bjno X-Received: by 2002:a17:907:6d18:b0:c29:448b:f5d0 with SMTP id a640c23a62f3a-c2a15b86ed4mr1180156066b.33.1790084235477; Tue, 22 Sep 2026 06:37:15 -0700 (PDT) Received: from [10.54.182.141] (82-132-213-196.dab.02.net. [82.132.213.196]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-c2aa9b14925sm14081966b.19.2026.09.22.06.37.11 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 22 Sep 2026 06:37:14 -0700 (PDT) Message-ID: Date: Tue, 22 Sep 2026 14:37:08 +0100 Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 06/13] nvme-pci: implement dma-buf backed requests To: Christoph Hellwig Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, Sumit Semwal , =?UTF-8?Q?Christian_K=C3=B6nig?= , Keith Busch , Sagi Grimberg , Alexander Viro , Christian Brauner , Jan Kara , Andrew Morton , Jens Axboe , Nitesh Shetty , Kanchan Joshi , Anuj Gupta , Tushar Gohad , William Power , Phil Cayton , Matthew Brost , Alasdair Kergon , Mike Snitzer , Mikulas Patocka , Benjamin Marzinski , dm-devel@lists.linux.dev References: <20260922132016.GA30684@lst.de> Content-Language: en-US From: Pavel Begunkov In-Reply-To: <20260922132016.GA30684@lst.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Christoph, On 9/22/26 14:20, Christoph Hellwig wrote: > On Mon, Sep 21, 2026 at 02:38:50PM +0100, Pavel Begunkov wrote: >> Enable BIO_DMABUF_MAP backed requests. On registration we map the > > This is now REQ_DMABUF. Will change > Sashiko had a few comments, which I think are correct - if we use > dma_map_sg to map the data, we need to use the sync_sg APIs to > transfer ownership. That only matters on non-coherent architectures > with MMU, but we need to get it right. I've seen that and fixed everything locally that should be fixed, apart from the sync. I wonder what we can do about that? I can somehow replace it with the sg variant for now, but sync'ing the entire possibly multi-GB mapping for, let's say, a 512B I/O, sounds not wise. And I can think of another place that does mix sync_single with sgs. > And the reset deadlock also looks plausible. -- Pavel Begunkov