From: Jason Gunthorpe <jgg@nvidia.com>
To: Jakub Kicinski <kuba@kernel.org>
Cc: Jiri Pirko <jiri@nvidia.com>, Leon Romanovsky <leon@kernel.org>,
Ido Schimmel <idosch@idosch.org>, Jiri Pirko <jiri@resnulli.us>,
"David S . Miller" <davem@davemloft.net>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
edwin.peer@broadcom.com
Subject: Re: [PATCH net-next] devlink: Require devlink lock during device reload
Date: Tue, 9 Nov 2021 14:24:27 -0400 [thread overview]
Message-ID: <20211109182427.GJ1740502@nvidia.com> (raw)
In-Reply-To: <20211109082042.31cf29c3@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
On Tue, Nov 09, 2021 at 08:20:42AM -0800, Jakub Kicinski wrote:
> On Tue, 9 Nov 2021 11:33:35 -0400 Jason Gunthorpe wrote:
> > > > I once sketched out fixing this by removing the need to hold the
> > > > per_net_rwsem just for list iteration, which in turn avoids holding it
> > > > over the devlink reload paths. It seemed like a reasonable step toward
> > > > finer grained locking.
> > >
> > > Seems to me the locking is just a symptom.
> >
> > My fear is this reload during net ns destruction is devlink uAPI now
> > and, yes it may be only a symptom, but the root cause may be unfixable
> > uAPI constraints.
>
> If I'm reading this right it locks up 100% of the time, what is a uAPI
> for? DoS? ;)
>
> Hence my questions about the actual use cases.
Removing namespace support from devlink would solve the crasher. I
certainly didn't feel bold enough to suggest such a thing :)
If no other devlink driver cares about this it is probably the best
idea.
Jason
next prev parent reply other threads:[~2021-11-09 18:24 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-31 17:35 [PATCH net-next] devlink: Require devlink lock during device reload Leon Romanovsky
2021-11-01 7:12 ` Ido Schimmel
2021-11-01 15:03 ` Jiri Pirko
2021-11-01 20:52 ` Ido Schimmel
2021-11-01 23:11 ` Jakub Kicinski
2021-11-07 17:16 ` Ido Schimmel
2021-11-07 17:54 ` Leon Romanovsky
2021-11-08 16:09 ` Jakub Kicinski
2021-11-08 17:32 ` Leon Romanovsky
2021-11-08 18:16 ` Jakub Kicinski
2021-11-08 18:24 ` Leon Romanovsky
2021-11-08 18:46 ` Jakub Kicinski
2021-11-08 19:58 ` Leon Romanovsky
2021-11-08 23:31 ` Jakub Kicinski
2021-11-09 14:12 ` Leon Romanovsky
2021-11-09 14:17 ` Jakub Kicinski
2021-11-09 14:30 ` Leon Romanovsky
2021-11-09 14:49 ` Jakub Kicinski
2021-11-09 16:29 ` Jiri Pirko
2021-11-09 14:43 ` Jason Gunthorpe
2021-11-09 15:07 ` Jakub Kicinski
2021-11-09 15:33 ` Jason Gunthorpe
2021-11-09 16:20 ` Jakub Kicinski
2021-11-09 18:24 ` Jason Gunthorpe [this message]
2021-11-11 12:05 ` Jiri Pirko
2021-11-11 12:17 ` Leon Romanovsky
2021-11-12 7:38 ` Jiri Pirko
2021-11-14 6:19 ` Leon Romanovsky
2021-11-15 11:20 ` Jiri Pirko
2021-11-15 12:53 ` Jason Gunthorpe
2021-11-15 14:42 ` Jiri Pirko
2021-11-15 15:09 ` Jason Gunthorpe
2021-11-15 15:22 ` Jakub Kicinski
2021-11-16 7:00 ` Jiri Pirko
2021-11-16 13:45 ` Jakub Kicinski
2021-11-16 6:57 ` Jiri Pirko
2021-11-16 12:44 ` Jason Gunthorpe
2021-11-17 14:15 ` Leon Romanovsky
2021-11-10 7:52 ` Leon Romanovsky
2021-11-09 16:15 ` Jiri Pirko
2021-11-09 16:26 ` Jakub Kicinski
2021-11-09 16:30 ` Jiri Pirko
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