From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f54.google.com (mail-wr1-f54.google.com [209.85.221.54]) (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 88E6A3E0754 for ; Mon, 18 May 2026 09:24:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.54 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779096284; cv=none; b=VISd0jgN2KxM0cuKJ4/e6YfB46+19IukX9He8+A2uN980x+VhdHmh/iJq0VQLMKVjiwrmrqoGCFdtNWyigaQjuUIe2kER8xaaHp1clgpjybNYwns9WQIpKqyPfug2c5IzIW1IVRO2LXlWzpbRALsLWrEiI4mc0wUjEU5hDB4SbU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779096284; c=relaxed/simple; bh=aFahUNzTuRd9lUxR1CTcAQQJqOKmfE/dGIcc0XxoVMU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=LcbGQpvp7Uei2RcRgFeDuUr2WXStsNdifZ6HUZDdZ2iyAjH+vNGBvSbsMb0Cc2eJz8c6zj6FSTRt6vm/Po+wy4T4p1HsQ6/tcxVnt/MY/T5tzKfBcPADmk2f5CY6+Y4TFsKmOWHN+XKhvVGjrAvCmWGbeypFd2ZRfJOZU5oqFcw= 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=AlgdSvCf; arc=none smtp.client-ip=209.85.221.54 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="AlgdSvCf" Received: by mail-wr1-f54.google.com with SMTP id ffacd0b85a97d-43fe62837baso1049143f8f.3 for ; Mon, 18 May 2026 02:24:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1779096281; x=1779701081; darn=vger.kernel.org; h=content-transfer-encoding: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; bh=8ZnntFD93TY8/+xleaPVExk6NAT6He9j34KXY+n97WI=; b=AlgdSvCf0TRu9rJVleCHIzTcmD0GE+h3APf3VOfOZ1cbKpW6GubpjmhF4EwezjT5Vt TFs148AA7KCfRr+bwmWp3MR9SeVp2uvP+/gyUY5RvFBzbx2+gE7bTh09tdzJtCLELo0Q uYfcJCy9co8Wmd78W0TW+VrsKOeFaP4DATPE+fE0duTTx8VKUBBegBIstHdXyVNG/jLe gR6QTjNp8CNjx8WObfme7ar4nvVxXSf7b8cPeyguI2sxfZRylKWUUlIDpwrd025MhsLo CWCZpDS2CHpDJZUhf6x3MUl5XT6+wbbN2PUag9gYzY4dNJatC6vz777RWxanc9PlAtOi IozQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779096281; x=1779701081; h=content-transfer-encoding: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; bh=8ZnntFD93TY8/+xleaPVExk6NAT6He9j34KXY+n97WI=; b=mX3CAm3tKAcpui0VY7yC57MfJhFqRY5zJiVVjLJtwzYNhKoXkO+BjA0jqnxUuNCA/k 1Hwg6ZbOl1AVX0ITNxPTxNXgWWs0AQXs2fJ+YAhDGvvfSbWwKqbj8ZYmxGrevP2YNDLv kF3D0f182dE5EimCmxrxSGEpXpLkjj3hyEbFQ3t12ISfa16XkWfBnxSXJEdDCzkOhRJG 0uFFyzHmVLDfOVwcRHMXLIYAfOjb780twbQ4tN/YIWmL/nT1VcLike0sfDIwUm6CiqGv GqUoLd3IemOE5px++4EJx3UIMebkHtHGE++hmzKiZpai1ay1NnJbw8mvsE9ndH+TgQug wLVg== X-Forwarded-Encrypted: i=1; AFNElJ+ShRrCG9MYsVopU18aGxWAlNUlKTlBPugASsorhovy9x4OsLZq6nGXxJ0qsyngY9Kr7C3WZXtTeccEPA==@vger.kernel.org X-Gm-Message-State: AOJu0YwqeWVjsJDuTbbEvnyRPynuReQHbvQNWtorNl2Iu0x+AeeKInHW A0ZCgVYFeUtOw9DmLvhzhNmrVcWI2KHzQBkkVv8ZQ6JKOxjSsAHLtMk2 X-Gm-Gg: Acq92OFjzKTrj36pNkSyX2kFuvH6uxH4Tq1oSFdTmRsBfWIOJi5KSWq6EKrqKi+v68p HMIrg2djd3lypC2eVj9mYQzrSVgD4GRyU+St/dJgZwpa/LrpLFX78Qja7PRtd5lWAeS5CuNfOAC yuiWhx7YOsKpIkJlUUrlXXBlcpg9o5oPsv/307sbhqGmUvWKRp7evSYjJbrVAbUIDf4GUYpbNxI PmzUnnVrNmeyGtKJ9l5uRf6SbymoSvziLptK6UJcb6eJQgd99OqlCnZHOvanGmEBDqyQMHIcq1v wL5+U0lnilZvprwDdLVdZUvw0fpIehoxfXLEbOzQyNN0vlZlHcGh0n25rUChSRQviFHWFGmPpvc 3ciW2OSAKQPjehsU+1w4DLhr6EnD4+neLYFxwhrTdo0NRYtLoRdMDJ3ZmN10ZGzg81MewKHFkkJ Q27e/R11OwTHeIRQBpnF6RViQGEFaVl3VrJSSadBmTIiFcYZhni8oqbu4J2qjKziAqWqlkL7Tyc tZUiYW+kjNELCwGJKoN7Y7eSHOT1P6fwmJij/ZdJqkhhV4n3TU5DgyrR0Y= X-Received: by 2002:a05:6000:288c:b0:43b:962b:5314 with SMTP id ffacd0b85a97d-45e5c372a9cmr22814328f8f.19.1779096280750; Mon, 18 May 2026 02:24:40 -0700 (PDT) Received: from ?IPV6:2620:10d:c096:325:77fd:1068:74c8:af87? ([2620:10d:c092:600::1:6e9b]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-45e6a135f0csm17325957f8f.27.2026.05.18.02.24.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 18 May 2026 02:24:40 -0700 (PDT) Message-ID: <4b2f74e9-3225-47f6-85fe-911720030e35@gmail.com> Date: Mon, 18 May 2026 10:24:35 +0100 Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 02/10] iov_iter: add iterator type for dmabuf maps To: David Laight Cc: Jens Axboe , Keith Busch , Christoph Hellwig , Sagi Grimberg , Alexander Viro , Christian Brauner , Andrew Morton , Sumit Semwal , =?UTF-8?Q?Christian_K=C3=B6nig?= , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, Nitesh Shetty , Kanchan Joshi , Anuj Gupta , Tushar Gohad , William Power , Phil Cayton , Jason Gunthorpe References: <20a233d2f35274817aa643cc0fe113707eb47e72.1777475843.git.asml.silence@gmail.com> <20260513110557.705bdeed@pumpkin> <20260513142909.03ae6c2b@pumpkin> Content-Language: en-US From: Pavel Begunkov In-Reply-To: <20260513142909.03ae6c2b@pumpkin> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 5/13/26 14:29, David Laight wrote: > On Wed, 13 May 2026 11:05:57 +0100 > David Laight wrote: > > ... >>> @@ -575,7 +575,8 @@ void iov_iter_advance(struct iov_iter *i, size_t size) >>> { >>> if (unlikely(i->count < size)) >>> size = i->count; >>> - if (likely(iter_is_ubuf(i)) || unlikely(iov_iter_is_xarray(i))) { >>> + if (likely(iter_is_ubuf(i)) || unlikely(iov_iter_is_xarray(i)) || >>> + unlikely(iov_iter_is_dmabuf_map(i))) { >> >> >> Doesn't the extra check add more code to all the non-ubuf cases? >> This could be fixed by either making iter_type a bitmask (with one bit set) Not going to do that. It was specifically converted from bitmask before, and the check optimisations like this were voiced back than. >> or writing an iter_is_one_of(i, ITER_xxx, ITER_yyy) define that uses >> '(1 << i->iter_type) & ((1 << ITER_xxx) | ...)' > > This seems to DTRT: > > #define _ITER_IS_ONE_OF(iter, t1, t2, t3, t4, t5, t6, t7, t8, ...) \ > ((1u << (iter)->iter_type) & ((1u << ITER_##t1) | (1u << ITER_##t2) | \ > (1u << ITER_##t3) | (1u << ITER_##t4) | (1u << ITER_##t5) | \ > (1u << ITER_##t6) | (1u << ITER_##t7) | (1u << ITER_##t8))) > #define ITER_IS_ONE_OF(iter, t, ...) \ > _ITER_IS_ONE_OF(iter, t, ## __VA_ARGS__, t, t, t, t, t, t, t) We definitely don't want that, using them directly would've been much cleaner. if (get_type_mask(i) & (TYPE1 | TYPE2)) ... -- Pavel Begunkov