From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-186.mta0.migadu.com (out-186.mta0.migadu.com [91.218.175.186]) (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 DDBDD7D3F5 for ; Wed, 22 May 2024 07:57:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.186 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716364655; cv=none; b=fAzvwiLHGMhA2c1WWxShpHV9F4LzzbIw8bHukeT+qBBKaK+V/luWB1qqAAQU9vqS3dvnv0K41dcapkHW+gntv/MPB2Ik5Xb249MlxxmZjOdPc9Me06Xm52DMWxC+eAia7RECk/l3lbRIuF2xNTFk3lkNkPmyhUVZSzaSRSSWVWU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716364655; c=relaxed/simple; bh=VENSe/3fAzfnCYpmQ+vOkNLmF9dyos3VXFyL/qFe9Fk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=BCRczJzokOckohWrMuDDGan9LQ2fVNPkHcZ3fxo3r8U80FWnO6DOpriWP74uS3fbwJUK0RSXf5/ru+lZTY5KTBeHuFWU1MsGzpvaGEN+ZZjBv5ttBSc/BgmvrLcInhO4cXhMGIDzCaL3iXdSIdK3/HRxJzbisIz51KoHQqA3fI4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=TAHrfs3Y; arc=none smtp.client-ip=91.218.175.186 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="TAHrfs3Y" X-Envelope-To: sagi@grimberg.me DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1716364650; 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=Q92zTs2hrsCm+boecXXID3PF9h+RjuwanNGz8edsrSQ=; b=TAHrfs3Y8yNuB1TtftU9qd8NmIrlGqNEHAiz55cvRNh2EB+gXX1SJF73QkCHDLcAa/IxJF dKU4jx2Xn21qPdexOcz22Qk+JtgpD2az77negdmh1Zl3poZG7xHiJC1N0xdL5IsUe8jJmM wtPc8NGA2ADTc4XtB+c+iLPhWV6CcDQ= X-Envelope-To: jgg@nvidia.com X-Envelope-To: chuck.lever@oracle.com X-Envelope-To: linux-nfs@vger.kernel.org X-Envelope-To: linux-rdma@vger.kernel.org Message-ID: <573f7e57-7599-4540-9dd7-622f7eedde79@linux.dev> Date: Wed, 22 May 2024 09:57:27 +0200 Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: Safe to delete rpcrdma.ko loading start-up code To: Sagi Grimberg , Jason Gunthorpe Cc: Chuck Lever III , Linux NFS Mailing List , "linux-rdma@vger.kernel.org" References: <8cc80bdb-9f17-4f44-b2e6-54b36ac85b63@grimberg.me> <20240521124306.GE20229@nvidia.com> <5b0b8ffe-75ad-4026-a0e8-8d74992ab7b6@grimberg.me> <20240521133727.GF20229@nvidia.com> <46c36727-ef93-44ca-9741-df2325d4420c@grimberg.me> <20240521152325.GG20229@nvidia.com> <20240521163713.GL20229@nvidia.com> <0f9ddfe5-67ff-470b-8901-d513dceb757e@grimberg.me> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Zhu Yanjun In-Reply-To: <0f9ddfe5-67ff-470b-8901-d513dceb757e@grimberg.me> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT 在 2024/5/21 22:30, Sagi Grimberg 写道: > > > On 21/05/2024 19:37, Jason Gunthorpe wrote: >> On Tue, May 21, 2024 at 07:10:53PM +0300, Sagi Grimberg wrote: >>> >>> On 21/05/2024 18:23, Jason Gunthorpe wrote: >>>> On Tue, May 21, 2024 at 05:12:23PM +0300, Sagi Grimberg wrote: >>>>>>>>> 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.. >>>>>>> nvme/nvmet/isert are requested by the kernel. >>>>>> How? What is the interface to trigger request_module? >>>>> On the host, writing to the nvme-fabrics misc device a comma-separated >>>>> connection string >>>>> contains a transport string, which triggers the corresponding >>>>> module to be >>>>> requested. >>>> But how did nvme-fabrics even get loaded to write to it's config fs in >>>> the first place? >>> Something (/etc/modules-load?) loaded it intentionally. >>> That something knows about a concrete intention to use nvme though... >> This mechanism we are talking about is an add-on to /etc/modules-load >> that only executes if rdma HW is present. > > Still does not mean you want to use all the ulps though... > >> >> This is why it is a good place to load nvme-fabrics stuff, if you >> don't have rdma HW then you know you don't need it. > > Do I want to autoload nvme-fabrics if I have a nvme device? do I want > autoload nvme-tcp if I have an ethernet nic? maybe wlan nic is also a > sufficient reason? > > I just don't see why the presence of an rdma device dictates that all > the ulps > autoload. Does rxe/siw count as rdma HW? RXE/SIW can be auto loaded with the command "rdma link ...". And some kernel modules, for example ib_core.ko, udp_tunnel.ko, ip6_udp_tunnel.ko and ib_uverbs.ko, are also auto-loaded when rxe/siw kernel modules are loaded. RXE/SIW are emulation RDMA kernel drivers. They are based on NIC HW. Normally all the NICs can support RXE/SIW RDMA drivers because RXE/SIW do not require additional NIC features. To now almost all the NIC HW can support RXE/SIW, even some virtual NICs can also support RXE/SIW, for example, bonding, TUN and veth. Zhu Yanjun > >> >> Autoloading is the version where you do 'mount -tnfs -o=rdma' and the >> kernel automatically request_module's nfs and then nfs-rdma based only >> on the command line options. >> >> I'm not sure this is even possible with configfs as the directories >> you need to write into don't even exist until the module(s) are >> loaded, right? > > Right. The entry-point of the subsystem needs to be loaded (nvmet is > loaded by nvmetcli), > the individual transports/drivers are auto-selected.