From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 DC6981A9F91; Tue, 17 Feb 2026 05:36:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771306587; cv=none; b=BqznZvBYBzrGpZeZlm/f2BKwIEqijSJ5ScMh9SlTzdNU28tVD992tkSfHkw9zJZCSFUeUgYaSIeYGi4Ge2lIFmwWsgclhBG9Hzjzo46KD5hLSha6C5mhY9OIPzOVg59QX69rV7tdNU97jig5UeVc+cVZEKBDwRjGLXsrsx6Q76s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771306587; c=relaxed/simple; bh=Vw1yWF0Y4bPZu/NH62MxUlVYzxnY8/zuN6APZzd3cr4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Ghq3iByGR5x1V6BD6Uu1kl3UEJtYObQdf6iYngTrb6/DlDTps25p/1ZjnCIFvw82lsju3ObNFE7kPjVl+zOMAYRCzPvHeIFPAL3kL/ja2ANWSq0pxpCcKlKjy6omxVk4nw7BuobBTeEWeyJmEiL7ydqddj0jWdz33JiA903Bvco= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=3OXEl1VB; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="3OXEl1VB" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=oUQd9aN1YNBwK0GRI+zqCnDPDmHN4dFR3i34SLyEQnM=; b=3OXEl1VBLrOHijeRAD7VI3lMfQ Cpgb3Mg3Gc2RQLyXOxxwIobsVsAAYJfMIJG9W/ketJBmeyfCBOeNv2XvoA8X/p5CNadtxEfaFei3q 37xEDroiFdq4W1Dd8+fOqZ+g4ZIzEfjSZJnLdCcun4RQt0W08KidCpQkXz/dKCBB7ZXd67Cd4vRfI iWRoCo3qnuhevqmU4+NKVthLbRMe4GO9FWLr0fycnwy4l/+7fuY7yeLo/uNrPGAUUbWpbbutWgQ9N HCCuEbqQ0fWKstEdO9Lnqwjbnw7h6mbIO0sd8tr2Ujb7mtWaL+wjX9p5pe7wWTfhUQyCS35i1/v/Y Ii1SsKDw==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vsDky-00000007eLL-2Ka6; Tue, 17 Feb 2026 05:36:20 +0000 Date: Mon, 16 Feb 2026 21:36:20 -0800 From: Christoph Hellwig To: Joanne Koong Cc: Pavel Begunkov , Christoph Hellwig , axboe@kernel.dk, io-uring@vger.kernel.org, csander@purestorage.com, krisman@suse.de, bernd@bsbernd.com, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v1 03/11] io_uring/kbuf: add support for kernel-managed buffer rings Message-ID: References: <89c75fc1-2def-4681-a790-78b12b45478a@gmail.com> <1c657f67-0862-4e13-9c71-7217aeecef61@gmail.com> <809cd04b-007b-46c6-9418-161e757e0e80@gmail.com> <7c241b57-95d4-4d58-8cd3-369751f17df1@gmail.com> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Fri, Feb 13, 2026 at 11:09:13AM -0800, Joanne Koong wrote: > > I think the circular buffer will be useful for Christoph's use case in > the same way it'll be useful for fuse's. The read payload could be > differently sized across requests, so it's a lot of wasted space to > have to allocate a buffer large enough to support the max-size request > per entry in the io_ring. Yes. > With using a circular buffer, buffers have a > way to be shared across entries, which means we can significantly > reduce how much memory needs to be allocated. Or enable such flexible use cases at all.