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 A3057C282D1 for ; Thu, 6 Mar 2025 15:18:02 +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=fErD4g+JYTWLuM8iylxwcedkdZfQJDmhUjqElG+nVuY=; b=V+9vWL1ee/+iULPDkseCYBgEZs ANNfRA0F0J1wrTF9snoVKV5Kx/wLR7T66aRdReoVDsI/m0ZoSGX3rnBn4q0cPGXnfjg7foDr7tzC6 fsxQhVQ6EO6fcZOGDExJge+DYaJ0ay3k1HXOddR5IWtCncrCGjl/lpurzYswHQzkBxUqwMqXHhhaq VCjqY1hO428mnFawLK5XbUweNKPBeT4HjInxLYvGZpvXLbBh9VNyM7s5MA3z8jcnZAQsWCHMoROkR 1QB4U88MNQGyuT+yAWQM2fUD0Fh1jqVBTOeyxfDtxBf75XzevQLUhT8Who/oQ4eV5sYO7KRNNP5HG Tjris93A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tqCz0-0000000BIE6-2iQe; Thu, 06 Mar 2025 15:17:58 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tqCyG-0000000BIAh-0IlS for linux-nvme@bombadil.infradead.org; Thu, 06 Mar 2025 15:17:12 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=fErD4g+JYTWLuM8iylxwcedkdZfQJDmhUjqElG+nVuY=; b=Onr+ktjrRUhYBEYVw+YAwN7daf aa+u09kGjdHC3lLoXhk66ofuwCz6ePxyynMbTj16X4KRuuV4yPqvgLv9prg0cj5liMWGU4z8ZK2QL aXPyQkqQs/bJjfdajYmOYKalEWExURDYEF4CUh/ySu7+opTTdKxpkMsDldfoBAPQt3UI4tMiFHd+G BmKxg7AIeGKrCUEXFBQ+JmfEkTVW/9kRT8xXO4FnotKw3FZctCun64sdVj0OSbvOX0Hh0T/tyIwvG FIv3b2y8krBkjaxMvsq6FvsIUMDipAqJdSMk1wAXrihH80P7SRupzhOGouB49FxAG+J/4tLKwMxSw fYm5C14w==; Received: from verein.lst.de ([213.95.11.211]) by casper.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tqCyA-0000000AP88-41Gt for linux-nvme@lists.infradead.org; Thu, 06 Mar 2025 15:17:10 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id A15AC68C4E; Thu, 6 Mar 2025 16:16:54 +0100 (CET) Date: Thu, 6 Mar 2025 16:16:54 +0100 From: Christoph Hellwig To: Keith Busch Cc: Christoph Hellwig , Hannes Reinecke , Sagi Grimberg , Nilay Shroff , John Meneghini , bmarzins@redhat.com, Bryan Gurney , linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, Marco Patalano , axboe@kernel.dk Subject: Re: [PATCH] nvme: remove multipath module parameter Message-ID: <20250306151654.GA22810@lst.de> References: <91ae613a-7b56-4ca0-b91c-6bc1eee798b8@suse.de> <20250305141554.GA18065@lst.de> <20250305235119.GB896@lst.de> <20250306000348.GA1233@lst.de> <1ffebf60-5672-4cd0-bb5a-934376c16694@suse.de> <20250306141837.GA21353@lst.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-20250306_151707_800428_36A21B7F X-CRM114-Status: GOOD ( 13.01 ) 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 Thu, Mar 06, 2025 at 08:01:19AM -0700, Keith Busch wrote: > > If the device is indeed entirely single ported and Samsung can confirm > > the setting is incorret and not easily fixable by a firmware update > > we can quirk it. > > It's not one vendor or device. I've not seen in in the wild so it can't be that common. > Or consider a true multiport PCIe where each port connects to a > different host. Each host sees a single port so they're not using > multipath capabilities, and the admin wants the MD behavior that removes > a disk on hot plug. Or even if one host sees both paths of a multiport > PCIe, they still might want that hot plug behavior. The module parameter > makes that possible, so some equivalent should be available before > removing it. A module-wide parameter is absolutely the wrong way to configure it. You'd ad best want it per-controller or even per-namespace. One tradeoff would be to disable the multipath code for private namespaces, although that would cause problems when rescanning changes the flag.