From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 008.lax.mailroute.net (008.lax.mailroute.net [199.89.1.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 09070224D1; Thu, 3 Oct 2024 22:00:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=199.89.1.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727992834; cv=none; b=t7dI7ltpnhtrCSAGXnoHW5+2Vi/j0lK6a4CG1o/lHDFwCgkEhbF6akC7QHa6BRxyE+sqQ17z8/IBUPydVjhXI03/3VuUtHr/s0iWDHRQhlluRKMyMAKhooX4aFIrikq64VrJsFH2RdKH9yiJx3oIOn2FbB4KwAsfmIW/M8VGnMM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727992834; c=relaxed/simple; bh=IVj+wSsh4cf2uBOXlAJ67cfhtx5pQhOFpZ/jN++jz9o=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=nJVcVaLtf4tvkKwfQl01weDs/eCXw5mzQf9LIAYPxHMi0Mtiu+SZn58vsFP3gp+yvkDGKn8TbT0NEFZQgDsGig2wiUlnywCRdP8qVy51mqKqUHEk4jCIU6FiUV30O81+nIesbeFVIKDxymS9TIHxO/Ru9ejBmjh4r5ccdmtQucA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org; spf=pass smtp.mailfrom=acm.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b=ZJIG9etA; arc=none smtp.client-ip=199.89.1.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=acm.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b="ZJIG9etA" Received: from localhost (localhost [127.0.0.1]) by 008.lax.mailroute.net (Postfix) with ESMTP id 4XKQbN2JFNz6ClY9l; Thu, 3 Oct 2024 22:00:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=acm.org; h= content-transfer-encoding:content-type:content-type:in-reply-to :from:from:content-language:references:subject:subject :user-agent:mime-version:date:date:message-id:received:received; s=mr01; t=1727992824; x=1730584825; bh=IVj+wSsh4cf2uBOXlAJ67cfh tx5pQhOFpZ/jN++jz9o=; b=ZJIG9etAuWeFo63DpU/5WwAcTYG/bRzhE3wzJYpQ oBlGAqnYxaBh+QVigZvS9kx6RYYOZkfl6xWqBUAt5BVnOJSoB3q4q6cz80o8aYvJ K2Shx0X1Rp/EttqJZWDy1nQ6nicWBMBk+7kCwtNmFw+8iVQtNCfTlmrvnNek6vK3 GkKMMCgkVLY6o5Oh/Z4Iv/qfKoyZ6UHjK1sTb06NdoazfzcJ6+H21i5awSnrXFG7 OxNoUffo9CbUWoWkio1vBZYQ5+rzzbgzGlhV/SS55svleC/L/5mWsp8qzDkBhGd4 45/JSp1kRUppFi4ixDePMIhrbbHgu2ZYiwFaYBROcz6N7g== X-Virus-Scanned: by MailRoute Received: from 008.lax.mailroute.net ([127.0.0.1]) by localhost (008.lax [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id TAmCIb-0ZlQg; Thu, 3 Oct 2024 22:00:24 +0000 (UTC) Received: from [100.66.154.22] (unknown [104.135.204.82]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bvanassche@acm.org) by 008.lax.mailroute.net (Postfix) with ESMTPSA id 4XKQbB4FqSz6ClY9k; Thu, 3 Oct 2024 22:00:22 +0000 (UTC) Message-ID: Date: Thu, 3 Oct 2024 15:00:21 -0700 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 v7 0/3] FDP and per-io hints To: Keith Busch , Christoph Hellwig Cc: "Martin K. Petersen" , Jens Axboe , Kanchan Joshi , hare@suse.de, sagi@grimberg.me, brauner@kernel.org, viro@zeniv.linux.org.uk, jack@suse.cz, jaegeuk@kernel.org, bcrl@kvack.org, dhowells@redhat.com, asml.silence@gmail.com, linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, linux-block@vger.kernel.org, linux-aio@kvack.org, gost.dev@samsung.com, vishak.g@samsung.com, javier.gonz@samsung.com References: <20241001092047.GA23730@lst.de> <99c95f26-d6fb-4354-822d-eac94fdba765@kernel.dk> <20241002075140.GB20819@lst.de> <20241002151344.GA20364@lst.de> <20241002151949.GA20877@lst.de> <20241003125516.GC17031@lst.de> Content-Language: en-US From: Bart Van Assche In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10/3/24 2:48 PM, Keith Busch wrote: > The only "bonus" I have is not repeatedly explaining why people can't > use h/w features the way they want. Hi Keith, Although that's a fair argument, what are the use cases for this patch series? Filesystems in the kernel? Filesystems implemented in user space? Perhaps something else? This patch series adds new a new user space interface for passing hints to storage devices (in io_uring). As we all know such interfaces are hard to remove once these have been added. We don't need new user space interfaces to support FDP for filesystems in the kernel. For filesystems implemented in user space, would using NVMe pass-through be a viable approach? With this approach, no new user space interfaces have to be added. I'm wondering how to unblock FDP users without adding a new controversial mechanism in the kernel. Thanks, Bart.