From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 6A8DA3A8D2 for ; Thu, 13 Mar 2025 21:46:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741902395; cv=none; b=VCsb5/aHXvyj0K6uAREX3JcnxalBjinaCESuimGEizMr0a7Zt/sQyb86X4XUKw8wFXgcjiwWk/p0B4qLu1bfg5ojV32piRjB5QvpXh92c+BBDaE4VEQ9xlbGQIr6SXT76jlYAMtBQ4kvRpe6p4J18Kl0z124ZNUKZLBSsd9o464= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741902395; c=relaxed/simple; bh=M4mhfs2GBioW5lVR2ZXKDAMdgwvxbEUESoYbNfVZyHM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ZN9BOp/Y3PyLok8WjbJkLzbKs+VprLgcpOrItzJ27xbtPVtYlGAWEZ9H8i7u1zgK+yDx1VpjmabW0Az0hlyYlie83MEwC9pUT5N5qO/w1+z4BZnFW4d4A7LQKgLzSpF3mozbpp1C4jlZrsy9Uq+GggOJaERPZkqABUoAvtI37dU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=H0uU/XC/; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="H0uU/XC/" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1741902392; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=tHS1SPZsy/hiD4YZfO5zi8XqrDds+QGmWBVIuyOLl44=; b=H0uU/XC/pwuKiP3uapf8OZIqOoupK4FtJmIXm3X3AJ/1uG/UdsdHlisCduo4NKLq7NtHkp 7TBMsiFRIwSxcdw/8duYamx4KIEmHF+iE/XDrcZ1QycujkJw51HrlezGQPiXqg3QtJr+aF zYFZl3SGNz+1hAgogTjaSc2rd+jOYng= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-110-ES6rCyx8P0Cppipgprzl9w-1; Thu, 13 Mar 2025 17:46:29 -0400 X-MC-Unique: ES6rCyx8P0Cppipgprzl9w-1 X-Mimecast-MFC-AGG-ID: ES6rCyx8P0Cppipgprzl9w_1741902388 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id CF82519560B7; Thu, 13 Mar 2025 21:46:27 +0000 (UTC) Received: from [10.22.80.28] (unknown [10.22.80.28]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 53BCF1800944; Thu, 13 Mar 2025 21:46:26 +0000 (UTC) Message-ID: Date: Thu, 13 Mar 2025 17:46:25 -0400 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/4] nvme-multipath: add the NVME_MULTIPATH_PARAM config option To: Christoph Hellwig Cc: kbusch@kernel.org, sagi@grimberg.me, loberman@redhat.com, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, emilne@redhat.com, bgurney@redhat.com References: <20250228032541.369804-1-jmeneghi@redhat.com> <20250228032541.369804-3-jmeneghi@redhat.com> <20250305143353.GB18526@lst.de> <03e7cc64-fafd-405e-a07a-4bc6d0e1d743@redhat.com> <20250312051958.GA11824@lst.de> Content-Language: en-US From: John Meneghini Organization: RHEL Core Storge Team In-Reply-To: <20250312051958.GA11824@lst.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 On 3/12/25 1:19 AM, Christoph Hellwig wrote: > On Tue, Mar 11, 2025 at 10:35:40PM -0400, John Meneghini wrote: >>> What's the point of adding yet another confusing option? >> >> If you'll read the kConfig description, hopefully it's not confusing. > > It still is. OK. I can fix that. >> The whole point of this patch series is to remove the core.nvme_mulipath parameter. > > Why would a compile time option be preferable over a runtime one? Because distos like RHEL don't allow customers to recompile their kernel. And including this runtime switch in the kernel let's users turn nvme-multipath off w/out recompiling the kernel. Our RHEL customers do this all of the time to enable DMMP with their NVMe devices. This has caused tremendous confusion and turmoil with our RHEL customers who keep on turning nvme-multipath off even when we ship RHEL with nvme-multipath on and we tell them turning it off is not supported. I finally decided that there is no good way to control this situation w/out removing the core.nvme_multipath parameter while CONFIG_NVME_MULTIPATH is enabled. This patch enables distros like RHEL simply config out the parameter w/out impacting all of the people out there who currently want and use the run time switch when CONFIG_NVME_MULTIPATH is enabled. Please let me know what I need to do to make these patches less confusing and get them accepted upstream. /John