From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.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.lore.kernel.org (Postfix) with ESMTPS id 2638BC4167B for ; Mon, 27 Nov 2023 13:58:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=lf40PTCxBv5iAG3/8E0RyfPSb8+F6NNBbJiqZ7gQ3ak=; b=hIyL0J/HIOqpILgNwKg5xWsNvU +jpteDv/PRcev7ZW7GTXSPI8eBd0BJseIR8WftRgW2C2CpRk6T26TLKiIYkteRqKkJ3hbFAOyYyGW EOeVdUte4StWU3CnW69ENiT1DNw6/yJ5rgvTugjSeMCieqquSBtmhuBg+UaeiOlKzyWeyumrxNi3o SjGLNAmn9sGnEvbOVkIHYHlFQvazPBJKcWrCgLC7hUoDbFRjEJw8HMdi/KSI0IsuHv1+YjC8dfjkX j5lg436grgNbUmHhhzOCCtIfRED4wG51xXbTf7ARBL3qc1fboYMW11QjCV4wMFpO4fEMtUISBJWCb HfHTX5gw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r7c7j-002dFc-0I; Mon, 27 Nov 2023 13:58:07 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1r7c7g-002dEm-0a for linux-nvme@lists.infradead.org; Mon, 27 Nov 2023 13:58:05 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 647A567373; Mon, 27 Nov 2023 14:57:55 +0100 (CET) Date: Mon, 27 Nov 2023 14:57:55 +0100 From: Christoph Hellwig To: Daniel Wagner Cc: Keith Busch , linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, Christoph Hellwig , Sagi Grimberg , Hannes Reinecke Subject: Re: [RFC v1] nvme: add cse, ds, ms, nsze and nuse to sysfs Message-ID: <20231127135755.GB23928@lst.de> References: <20231127103208.25748-1-dwagner@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231127_055804_383314_CF9125E6 X-CRM114-Status: GOOD ( 16.97 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Mon, Nov 27, 2023 at 01:07:32PM +0100, Daniel Wagner wrote: > libnvme itself is also cashing this value and exposes it via the > nvme_ns_get_lba_util() getter. I'd say libnvme shouldn't cache it > either. Instead the function should just issue the ns command to report > the current nuse value. > > I'll drop the nuse sysfs entry. > > Unfortunately, 'nvme list' is using the 'nuse' field for showing the > currently used space. I was hoping to get 'nvme list' working without > issuing any commands. I'd be ok with implementing nuse in a way where we issue an identify command to read it, but rate limit the calls to something reasonable. I think the kernel can do that much better than userspace because it can keep that state a lot better.