From: Jason Gunthorpe <jgg@ziepe.ca>
To: Ka-Cheong Poon <ka-cheong.poon@oracle.com>
Cc: linux-rdma@vger.kernel.org
Subject: Re: RDMA subsystem namespace related questions (was Re: Finding the namespace of a struct ib_device)
Date: Mon, 5 Oct 2020 12:45:48 -0300 [thread overview]
Message-ID: <20201005154548.GT9916@ziepe.ca> (raw)
In-Reply-To: <3e9497cb-1ccd-2bc0-bbca-41232ebd6167@oracle.com>
On Mon, Oct 05, 2020 at 11:02:18PM +0800, Ka-Cheong Poon wrote:
> On 10/5/20 10:25 PM, Jason Gunthorpe wrote:
> > On Mon, Oct 05, 2020 at 09:57:47PM +0800, Ka-Cheong Poon wrote:
> > > > > It is a kernel module. Which FD are you referring to? It is
> > > > > unclear why a kernel module must associate itself with a user
> > > > > space FD. Is there a particular reason that rdma_create_id()
> > > > > needs to behave differently than sock_create_kern() in this
> > > > > regard?
> > > >
> > > > Somehow the kernel module has to be commanded to use this namespace,
> > > > and generally I expect that command to be connected to FD.
> > >
> > >
> > > It is an unnecessary restriction on what a kernel module
> > > can do. Is it a problem if a kernel module initiates its
> > > own RDMA connection for doing various stuff in a namespace?
> >
> > Yes, someone has to apply policy to authorize this. Kernel modules
> > randomly running around using security objects is not OK.
>
> The policy is to allow this. It is not random stuff.
> Can the RDMA subsystem support it?
allow everything is not a policy
> > Kernel modules should not be doing networking unless commanded to by
> > userspace.
>
> It is still not clear why this is an issue with RDMA
> connection, but not with general kernel socket. It is
> not random networking. There is a purpose.
It is a problem with sockets too, how do the socket users trigger
their socket usages? AFAIK all cases originate with userspace
> So if the reason of the current rdma_create_id() behavior
> is that there is no such user, I am adding one. It should
> be clear that this difference between kernel socket and
> rdma_create_id() causes a problem in namespace handling.
It would be helpful to understand how that works, as I've said I don't
think a kernel module should open listening sockets/cm_ids on every
namespace without being told to do this.
> If the cma_wq is re-designed, number of namespaces should be one
> input parameter on creating how many threads and other resources
> allocation/scheduling. One cma_wq per namespace is the simplest
> allocation.
no, it will just run all CM_IDs concurrently on all processors.
Namespaces are not cgroups, we don't guarentee anything about resource
consumption for namespaces.
Jason
next prev parent reply other threads:[~2020-10-05 15:45 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-03 14:02 Finding the namespace of a struct ib_device Ka-Cheong Poon
2020-09-03 17:39 ` Jason Gunthorpe
2020-09-04 4:01 ` Ka-Cheong Poon
2020-09-04 11:32 ` Jason Gunthorpe
2020-09-04 14:02 ` Ka-Cheong Poon
2020-09-06 7:44 ` Leon Romanovsky
2020-09-07 3:33 ` Ka-Cheong Poon
2020-09-07 7:18 ` Leon Romanovsky
2020-09-07 8:24 ` Ka-Cheong Poon
2020-09-07 9:04 ` Leon Romanovsky
2020-09-07 9:28 ` Ka-Cheong Poon
2020-09-07 10:22 ` Leon Romanovsky
2020-09-07 13:48 ` Ka-Cheong Poon
2020-09-29 16:57 ` RDMA subsystem namespace related questions (was Re: Finding the namespace of a struct ib_device) Ka-Cheong Poon
2020-09-29 17:40 ` Jason Gunthorpe
2020-09-30 10:32 ` Ka-Cheong Poon
2020-10-02 14:04 ` Jason Gunthorpe
2020-10-05 10:27 ` Ka-Cheong Poon
2020-10-05 13:16 ` Jason Gunthorpe
2020-10-05 13:57 ` Ka-Cheong Poon
2020-10-05 14:25 ` Jason Gunthorpe
2020-10-05 15:02 ` Ka-Cheong Poon
2020-10-05 15:45 ` Jason Gunthorpe [this message]
2020-10-06 9:36 ` Ka-Cheong Poon
2020-10-06 12:46 ` Jason Gunthorpe
2020-10-07 8:38 ` Ka-Cheong Poon
2020-10-07 11:16 ` Leon Romanovsky
2020-10-08 10:22 ` Ka-Cheong Poon
2020-10-08 10:36 ` Leon Romanovsky
2020-10-08 11:08 ` Ka-Cheong Poon
2020-10-08 16:08 ` Jason Gunthorpe
2020-10-08 16:21 ` Chuck Lever
2020-10-08 16:46 ` Jason Gunthorpe
2020-10-09 4:49 ` Ka-Cheong Poon
2020-10-09 14:39 ` Jason Gunthorpe
2020-10-09 14:48 ` Chuck Lever
2020-10-09 14:57 ` Jason Gunthorpe
2020-10-09 15:00 ` Chuck Lever
2020-10-09 15:07 ` Jason Gunthorpe
2020-10-09 15:27 ` Chuck Lever
2020-10-09 15:34 ` Jason Gunthorpe
2020-10-09 15:52 ` Chuck Lever
2020-10-12 8:20 ` Ka-Cheong Poon
2020-10-16 18:54 ` Jason Gunthorpe
2020-10-16 20:49 ` Chuck Lever
2020-10-19 18:31 ` Jason Gunthorpe
2020-10-07 12:28 ` Jason Gunthorpe
2020-10-08 10:49 ` Ka-Cheong Poon
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