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[2604:1380:4601:e00::3]) by mx.google.com with ESMTPS id i22-20020a1709061cd600b00a237375dc19si390362ejh.846.2023.12.18.20.38.59 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Dec 2023 20:38:59 -0800 (PST) Received-SPF: pass (google.com: domain of linux-nfs+bounces-704-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=bombadil.20210309 header.b="n2/wn127"; spf=pass (google.com: domain of linux-nfs+bounces-704-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) smtp.mailfrom="linux-nfs+bounces-704-linux.lists.archive=gmail.com@vger.kernel.org" Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by am.mirrors.kernel.org (Postfix) with ESMTPS id 304A11F24248 for ; Tue, 19 Dec 2023 04:38:59 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 89C428479; Tue, 19 Dec 2023 04:38:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="n2/wn127" X-Original-To: linux-nfs@vger.kernel.org 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 277D68475 for ; Tue, 19 Dec 2023 04:38:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org 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=Kl27Zog8jaEvuys8g6UYmk943mgvE98EDx8AOjVKv+4=; b=n2/wn127TG3YpHhirchRtRiHYT 4xwoPh67VMR2yTiFerHTLWsrTnffnl6lRoo9OsJD76/gnw4hR0CyW+SwNOucNUS79v76lT1P2dBU6 9yg/EmJr0dtNEoqOOck95s0d1ul3ANJI5NaxaJwtXqzDujcMI/ln46vbWN22hODeHOGlYFVhOzcrC wVJunwUHb8PUCp/cfk2LoQSbhBuVLCD4HkK3n78VodZ9G3w7eIzUDFmaRF6ac+AWW/2QHN9Tq4dUP y+mdt54iQtl6cEwT1JIVbtN8oRmuQ/SeUmjQBJHkqjDWHErJE0kJ6SOEFHXay9A1cDufzCjqtGdQQ WOpRYBTw==; Received: from hch by bombadil.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1rFRsc-00Cons-1O; Tue, 19 Dec 2023 04:38:54 +0000 Date: Mon, 18 Dec 2023 20:38:54 -0800 From: Christoph Hellwig To: Cedric Blancher Cc: Linux NFS Mailing List Subject: Re: Realtime NFSv4? Message-ID: References: Precedence: bulk X-Mailing-List: linux-nfs@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 Mon, Dec 18, 2023 at 12:48:00PM +0100, Cedric Blancher wrote: > Good morning! > > How feasible would be a realtime NFSv4, which can guarantee NFSv4 > operations in a constant time manner suitable for realtime > applications (similar to XFS realtime support)? The XFS realtime subvoume is grossly misnamed, it does not guarantee anything at all. It just uses a separate, somewhat more predicatable allocator.