Received-SPF: pass (google.com: domain of linux-nfs+bounces-3303-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161;
Date: Tue, 21 May 2024 09:43:06 -0300
From: Jason Gunthorpe <jgg@nvidia.com>
To: Sagi Grimberg <sagi@grimberg.me>
Cc: Chuck Lever III <chuck.lever@oracle.com>,
	Linux NFS Mailing List <linux-nfs@vger.kernel.org>,
	"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>
Subject: Re: Safe to delete rpcrdma.ko loading start-up code
Message-ID: <20240521124306.GE20229@nvidia.com>
References: <DE53C92C-D16E-4FA7-9C0B-F83F03B1896F@oracle.com>
 <8cc80bdb-9f17-4f44-b2e6-54b36ac85b63@grimberg.me>
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <8cc80bdb-9f17-4f44-b2e6-54b36ac85b63@grimberg.me>
Precedence: bulk
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0:
	=?us-ascii?Q?qWkXBg5P6GCC29YJg5o8xT4medEjkxwmofAH9vZV7CMyEHwy0FZOaiORe4Qp?=
 =?us-ascii?Q?SrluLkdYx79ks6RNQhhMUJcvBc1QLTdFePMKZDxe8iDF/MtV184lCxjudTxd?=
 =?us-ascii?Q?me7dpbpQVUnyUDFkVfNP1qZ3Ozm4YeSp1nc+cKYc95EUvSbwDG6AIA1ZGXjs?=
 =?us-ascii?Q?OvRdb0WYchjlv4EKM7GIw2FPP1FpBR+vkLyZFyyst7TtIUVFQzTqucoWu5xB?=
 =?us-ascii?Q?FHxfoSRcYqh2Dbu/kbfqPXtxfYAIG9ZgrNUbfMrcmMr35sG0HwNgyBfKLVXb?=
 =?us-ascii?Q?5ADsZfYkrDvYDAjE81+nd+JH4TYaY/eLkXNm+vDVaz0zP0EByRGMMc8QGtkw?=
 =?us-ascii?Q?zt5OyGpIwPhiDbCdwAA8QHvH1yShfChWtx3zaaincFkJxQ6jeUsWSyn2hW0M?=
 =?us-ascii?Q?RVcmsFvLN3D7lR/PGq7YFoRINWy52ojVDwzD8wxsmZoYJcjGZmgVjjdTA6Cg?=
 =?us-ascii?Q?f9brzseVGampSvnqn2lRp8oIPUaog/JLVYtoI3fbQR0wUka4IIXAp3xUDHK4?=
 =?us-ascii?Q?Qs6P0JHJtquj3B+t8qKsBSFcIvwUboUJH7O4yPGTMFr+AOoo0xKgULaNcNZA?=
 =?us-ascii?Q?FWErgHjQx8vru+1ozW+Zxnv1AdouE8/jwKlgMpnPDObHRDL/EeBO+SgpeG9a?=
 =?us-ascii?Q?RsCjrFUE/VSSGcAQ5qfPop7xSDMn2FTyCE/x36EK77lJDNMrg63nNAl6M9bb?=
 =?us-ascii?Q?0SE9INl3DkJFv/Z+cWueJ09tVkpAVyHofCuZ9apqonPB79UOg5eKfDHqGppO?=
 =?us-ascii?Q?HL4Ipf8wAWZbpkqF0GlQ3MrUhWSsluvkduSXe3WVyLyfnkEs12fk8cxtAsGy?=
 =?us-ascii?Q?9Fp4h8o1MLzurm1b25pTOg6wbb6jcV3dCAM79f4nWEVOPUNtd4A1+zLbDbgG?=
 =?us-ascii?Q?no4Mi4G2Cw8H4GnIXYyYHV/weusmtLEHfIK/SEEL9TgOQ3EqwPcdWR0wlr/g?=
 =?us-ascii?Q?vpB2KxU4J+dLTLqzc6KhNpkB1rxAgC0aY/Bi6xfWMoPhoSi3qMX+TOHA9eb1?=
 =?us-ascii?Q?uyLRllSKHT0HHZzNekVhspQa/EO43NPG/DRJ3onAL1uibeIlM+ykul6N1CKU?=
 =?us-ascii?Q?El6otATLyY+CxMVtsjvEyZl8Dkce/ImVykxERGmlwBmIC7OAsE/yNtZT35vL?=
 =?us-ascii?Q?4eNdB3JjTSRGHWt7+XffKGioDtqvMGV+06INJot7MztSmZi/g68LonTor8X2?=
 =?us-ascii?Q?B2XsL7k/pqxis5OH5pPpmE4veCniAxgmjdhGgGYCr7JRdfRrWh6uWzeh+m0A?=
 =?us-ascii?Q?FkoSvEUc4ss5LjZUDtPCaaDpw83xiavSuFVay+dDlZz72rYPpiAUqdzNc4MD?=
 =?us-ascii?Q?+9cWdx2qkGSTWVMRyaqIEW4AWhZT/NVee4JxGai+9OGf5J/yU+9vFRkHpZGA?=
 =?us-ascii?Q?hye50KztFTB4O+AoU7mc9/1ZI9X8YyV424d4XIrPFSB+G8SLJQn/sEmFDlA7?=
 =?us-ascii?Q?dg9kpIED/VJFEq7tf72m/sp7LfLNLUWh6KZzkgHxjtOU4QnwV/zGXXRPGNTI?=
 =?us-ascii?Q?PsffKMx/dsEWJ5H6HMgIVWVG65ygvSSnwqYacl9Jr0gBIs+IfdC1LEUnpMdJ?=
 =?us-ascii?Q?bFC/NTubOklLnZtC7g8=3D?=
X-OriginatorOrg: Nvidia.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 40358957-89ab-47c2-7186-08dc799390d6
X-MS-Exchange-CrossTenant-AuthSource: DM6PR12MB3849.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 May 2024 12:43:07.8047
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: qDQsrwaZBh35wIhv0xpRmjDDf3tin7NMpmWprVuIY5o8y3AllE1cfxykjGktTZ3Z
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR12MB4234

On Tue, May 21, 2024 at 12:04:02PM +0300, Sagi Grimberg wrote:
> 
> 
> On 20/05/2024 21:05, Chuck Lever III wrote:
> > Hi-
> > 
> > I've tested this with two kinds of systems:
> > 
> > 1. A system with no physical RDMA devices and no start-up
> >     scripts to load these modules
> > 
> > 2. A system with physical RDMA devices and with the start-up
> >     scripts that load xprtrdma/svcrdma
> > 
> > In both cases, after doing an "rmmod rpcrdma", I can mount
> > a "proto=rdma" mount or start the NFS server, and the module
> > gets reloaded automatically.
> > 
> > I therefore believe it is safe to delete the code in the
> > rdma-core start-up scripts that manually load RPC-related
> > RDMA support. Either the sunrpc.ko module does this, or NFS
> > user space handles it. There's no need for the rdma-core
> > scripting.
> 
> I didn't know that rdma-core does this... it really shouldn't, the
> mount should (and does) handle it.

This is new, it didn't used to do this

> I also see that srp(t) and iser(t) are loaded too.. IIRC these are
> loaded by their userspace counterparts as well (or at least they
> should).

And AFIAK, these don't have a way to autoload at all. autoload
requires the kernel to call request_module..

ipoib is also a problem, we don't have a way to autoload it either

Jason