From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-io1-f45.google.com (mail-io1-f45.google.com [209.85.166.45]) (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 C845F21C9E0 for ; Fri, 21 Mar 2025 11:15:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.45 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742555704; cv=none; b=sqHzAaw5+NzRRH0eITeXMK+MLKDkd9QGb2G8thi+IqTZTWi5fFCE0aI1o6BydVLEEdPMwWn2Bl1hz71KFO3RJMn4RJCLOO10EZvjVRrvu+8ZbvnH/mrvYlCxv4BzeV+uQFCA7Xm45/u4rkL7qYpP7JxKSI1wh/ZeVakLj0TP2dI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742555704; c=relaxed/simple; bh=8R6APMOXHnSGsHWxrl6UGLerFw6XUN3eqFRa7zAvg/g=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=CIi2K1CpKDdbDVnqi/YV6rPFSSXZP/q/cFbUEOn6cseE1DiAkaiF/O2VhJxOyZU5YC0LUWpNxcpT02hZhwLSTBRu8DVGrtYH+lgqbpJuR3OabGQr46tSAxClfJCLKfPw66AtP3YLCh81C4HHBx+STJHXqAFcubjZIJcRnEr3ZK4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk; spf=pass smtp.mailfrom=kernel.dk; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b=Iw2c3QWk; arc=none smtp.client-ip=209.85.166.45 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.dk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b="Iw2c3QWk" Received: by mail-io1-f45.google.com with SMTP id ca18e2360f4ac-855fc51bdfcso84759839f.0 for ; Fri, 21 Mar 2025 04:15:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1742555702; x=1743160502; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:content-language:from :references:to:subject:user-agent:mime-version:date:message-id:from :to:cc:subject:date:message-id:reply-to; bh=kliUjv4+TXv1KW6sNWVHyeHcHrrjshrv681ijKNdLOI=; b=Iw2c3QWka8kkhnOcLtELQiQELaeqZuUMgS7kb4ZffDPthFqQU3UQDlpY8iqcb3lUCO GKiU26FrybIvWhJize1sjzcoBt/fFZ4EI5gmL1eYbygmKOOFOV3S05G6BqWzpEtclq3Q wwqF55+fYuET9ydA9yszlebqAhBovv4pEK6oIuWjAVkuhBFiY8+vzz+0u+3duQajcyTH vbXNd04PuBX2JNOWy0rOfPXwBbC9kqEnBufORUw/mt2FQa8SsEGFIN3268uERLv7P6wB Xa2DU71NwH/dwcyCjpPH7E35IEo13ZQNAAzp9urqcv+H8JoTQ3YUonE/S4YI1eXC9Xcg zbBg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1742555702; x=1743160502; h=content-transfer-encoding:in-reply-to:content-language:from :references:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=kliUjv4+TXv1KW6sNWVHyeHcHrrjshrv681ijKNdLOI=; b=UCfCHFaB5k9tDB19tlV+2YXOz2QclxYT49SQRhmqynXmX1u09om05ITL5Ez55OYEdZ xIhCBzjXc//6ndfKnbgFecb3PNsgWIHGWDvLvofsBb7q+DlorOe5EI1Q7D0txG/nkqZ2 Vm1oT0cG82MHHGBfG25epabABrHe44Ix98sQ+Z476VqAYgAlxWbRNRVdknJj0Iw9bj0u D5cBvI6yBZ+KnxKXXWdNGvOI8RGjeaMBRspGfDhxi6O9Z+HkAq+awy3SGrPm55hGE6qW jki82F3acppXgsY1FzNYziE98q4W6Laim1e4KbdD1YmGE7GI+RejxwdkKd3cIJM+KDTW 1suA== X-Forwarded-Encrypted: i=1; AJvYcCXSvpFy1b+2bi8wSTYrO3ZyEHOlahva3ZwxNGcDK3DR4gCqebQuyPzR0H+xzcyU7ycj6Jn5FCFvZCiiTNri@vger.kernel.org X-Gm-Message-State: AOJu0YxPlkutCCx/cMCXcbpz0ww9ocw3GnL2XMNvbda6GHiF7nNJBMg1 r+03QE1cbs0OBf+ZZvyfrsWXIdfRIumUg2l0QY1ZZQznmbUsaf3vTKh3X9I7mAE= X-Gm-Gg: ASbGncvi1nCXC/JZTI5h8XStbo/2OzAySQCs/mKMot3fSDxkrjAdZVOV76ACErCZ0eX oBIHM6KYD8C78MM1uOtSDONHpNVhQvD8xT85quEc8a2jjesOAn/3lKTorHtct/qYLueoNq0LetN ieK5KMa3P4GOComO0i9vjmnCpL5QJVZHGlRfHXmiDMQX9N5kH5QSZd8KtlGp+T4r1o5M49gVkYz 6TQt7lRDk6RyKFKTH2JKDrSMaefPo6+K4vhFCabzbuFNsE0V6zHgOV7wPK4Nq80yJ+1WNtH7biF nmod97KXqLAOz6N5NBoyzq3sZqElcwsAPQqg2VbS4w== X-Google-Smtp-Source: AGHT+IGFd8BrZDNuk5Q4tM4bK6u6ZIejPv4ztHl8dw4HSNWePmW9h5bgFFsMA3e+W8P/94Uoju3uaw== X-Received: by 2002:a05:6602:3991:b0:85b:5869:b5f with SMTP id ca18e2360f4ac-85e2beed32fmr322406139f.5.1742555701856; Fri, 21 Mar 2025 04:15:01 -0700 (PDT) Received: from [192.168.1.150] ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id ca18e2360f4ac-85e2bdb5495sm33739439f.46.2025.03.21.04.15.00 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 21 Mar 2025 04:15:01 -0700 (PDT) Message-ID: Date: Fri, 21 Mar 2025 05:14:59 -0600 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC -next 00/10] Add ZC notifications to splice and sendfile To: Christoph Hellwig , Joe Damato , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, asml.silence@gmail.com, linux-fsdevel@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, horms@kernel.org, linux-api@vger.kernel.org, linux-arch@vger.kernel.org, viro@zeniv.linux.org.uk, jack@suse.cz, kuba@kernel.org, shuah@kernel.org, sdf@fomichev.me, mingo@redhat.com, arnd@arndb.de, brauner@kernel.org, akpm@linux-foundation.org, tglx@linutronix.de, jolsa@kernel.org, linux-kselftest@vger.kernel.org References: <20250319001521.53249-1-jdamato@fastly.com> <2d68bc91-c22c-4b48-a06d-fa9ec06dfb25@kernel.dk> <19e3056c-2f7b-4f41-9c40-98955c4a9ed3@kernel.dk> From: Jens Axboe Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/20/25 11:56 PM, Christoph Hellwig wrote: >> I don't know the entire historical context, but I presume sendmsg >> did that because there was no other mechanism at the time. > > At least aio had been around for about 15 years at the point, but > networking folks tend to be pretty insular and reinvent things. Yep... >> It seems like Jens suggested that plumbing this through for splice >> was a possibility, but sounds like you disagree. > > Yes, very strongly. And that is very much not what I suggested, fwiw. >> As mentioned above and in other messages, it seems like it is >> possible to improve the networking parts of splice (and therefore >> sendfile) to make them safer to use without introducing a new system >> call. >> >> Are you saying that you are against doing that, even if the code is >> network specific (but lives in fs/)? > > Yes. > > Please take the work and integrate it with the kiocb-based system > we use for all other in-kernel I/O that needs completion notifications > and which makes it trivial to integate with io_uring instead of > spreading an imcompatible and inferior event system. Exactly, this is how we do async IO elsewhere, not sure why networking needs to be special here, and definitely not special in a good way. -- Jens Axboe