From: Jiri Pirko <jiri@resnulli.us>
To: Leon Romanovsky <leon@kernel.org>
Cc: Jacob Keller <jacob.e.keller@intel.com>,
Jakub Kicinski <kuba@kernel.org>,
davem@davemloft.net, netdev@vger.kernel.org, edumazet@google.com,
pabeni@redhat.com
Subject: Re: [PATCH net-next 7/9] devlink: allow registering parameters after the instance
Date: Fri, 13 Jan 2023 08:53:55 +0100 [thread overview]
Message-ID: <Y8EOE7WSlSP1SrBO@nanopsycho> (raw)
In-Reply-To: <Y8D+GjYZKvtstIC+@unreal>
Fri, Jan 13, 2023 at 07:45:46AM CET, leon@kernel.org wrote:
>On Thu, Jan 12, 2023 at 02:44:43PM -0800, Jacob Keller wrote:
>>
>>
>> On 1/12/2023 12:09 PM, Leon Romanovsky wrote:
>> > On Thu, Jan 12, 2023 at 11:20:21AM -0800, Jakub Kicinski wrote:
>> >> On Thu, 12 Jan 2023 09:07:43 +0200 Leon Romanovsky wrote:
>> >>> As a user, I don't want to see any late dynamic object addition which is
>> >>> not triggered by me explicitly. As it doesn't make any sense to add
>> >>> various delays per-vendor/kernel in configuration scripts just because
>> >>> not everything is ready. Users need predictability, lazy addition of
>> >>> objects adds chaos instead.
>> >>>
>> >>> Agree with Jakub, it is anti-pattern.
>> >>
>> >> To be clear my preference would be to always construct the three from
>> >> the root. Register the main instance, then sub-objects. I mean - you
>> >> tried forcing the opposite order and it only succeeded in 90-something
>> >> percent of cases. There's always special cases.
>
>Back then, we had only one special case - netdevsim. I still think that
>all recent complexity that was brought to the devlink could be avoided
>if we would change netdevsim to behave as HW driver (remove sysfs).
>
>> Right. I think its easier to simply require devlink to be registered first.
>
>devlink_register() is no more than a fancy way to say to the world: "I'm
>ready to accept commands". Right now, when the need_lock flag is removed
>from all devlink commands, we can place devlink_register() at any place.
>
>>
>> >> I don't understand your concern about user experience here. We have
>> >> notifications for each sub-object. Plus I think drivers should hold
>> >> the instance lock throughout the probe routine. I don't see a scenario
>> >> in which registering the main instance first would lead to retry/sleep
>> >> hacks in user space, do you? I'm talking about devlink and the subobjs
>> >> we have specifically.
>> >
>> > The term "dynamic object addition" means for me what driver authors will
>> > be able to add objects anytime in lifetime of the driver. I'm pretty sure
>> > that once you allow that, we will see zoo here. Over time, you will get
>> > everything from .probe() to workqueues. The latter caused me to write
>> > about retry/sleep hacks.
>> >
>> > If you success to force everyone to add objects in .probe() only, it
>> > will be very close to what I tried to achieve.
>> >
>> > Thanks
>>
>> Yea. I was initially thinking of something like that, but I've convinced
>> myself that its a bad idea. The only "dynamic" objects (added after the
>> initialization phase of devlink) should be those which are triggered via
>> user space request (i.e. "devlink port add").
>
>Exactly.
And reload as well.
>
>>
>> Thanks,
>> Jake
next prev parent reply other threads:[~2023-01-13 7:54 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-06 6:33 [PATCH net-next 0/9] devlink: remove the wait-for-references on unregister Jakub Kicinski
2023-01-06 6:33 ` [PATCH net-next 1/9] devlink: bump the instance index directly when iterating Jakub Kicinski
2023-01-06 12:17 ` Jiri Pirko
2023-01-06 6:33 ` [PATCH net-next 2/9] devlink: update the code in netns move to latest helpers Jakub Kicinski
2023-01-06 6:33 ` [PATCH net-next 3/9] devlink: protect devlink->dev by the instance lock Jakub Kicinski
2023-01-06 12:18 ` Jiri Pirko
2023-01-06 6:33 ` [PATCH net-next 4/9] devlink: always check if the devlink instance is registered Jakub Kicinski
2023-01-06 12:41 ` Jiri Pirko
2023-01-06 17:03 ` Jacob Keller
2023-01-06 21:19 ` Jakub Kicinski
2023-01-07 9:05 ` Jiri Pirko
2023-01-06 6:33 ` [PATCH net-next 5/9] devlink: remove the registration guarantee of references Jakub Kicinski
2023-01-06 12:42 ` Jiri Pirko
2023-01-06 6:33 ` [PATCH net-next 6/9] devlink: don't require setting features before registration Jakub Kicinski
2023-01-06 12:43 ` Jiri Pirko
2023-01-06 6:34 ` [PATCH net-next 7/9] devlink: allow registering parameters after the instance Jakub Kicinski
2023-01-06 12:55 ` Jiri Pirko
2023-01-06 21:22 ` Jakub Kicinski
2023-01-07 9:20 ` Jiri Pirko
2023-01-10 0:21 ` Jacob Keller
2023-01-10 16:35 ` Jiri Pirko
2023-01-10 20:22 ` Jakub Kicinski
2023-01-11 9:32 ` Jiri Pirko
2023-01-11 16:45 ` Jakub Kicinski
2023-01-11 21:29 ` Jacob Keller
2023-01-12 7:07 ` Leon Romanovsky
2023-01-12 14:59 ` Jiri Pirko
2023-01-12 19:58 ` Leon Romanovsky
2023-01-13 7:50 ` Jiri Pirko
2023-01-15 8:35 ` Leon Romanovsky
2023-01-16 10:33 ` Jiri Pirko
2023-01-16 11:25 ` Leon Romanovsky
2023-01-12 19:20 ` Jakub Kicinski
2023-01-12 20:09 ` Leon Romanovsky
2023-01-12 22:44 ` Jacob Keller
2023-01-13 6:45 ` Leon Romanovsky
2023-01-13 7:53 ` Jiri Pirko [this message]
2023-01-11 13:21 ` Jiri Pirko
2023-01-06 6:34 ` [PATCH net-next 8/9] netdevsim: rename a label Jakub Kicinski
2023-01-06 12:56 ` Jiri Pirko
2023-01-06 6:34 ` [PATCH net-next 9/9] netdevsim: move devlink registration under the instance lock Jakub Kicinski
2023-01-06 15:49 ` Jiri Pirko
2023-01-06 13:10 ` [PATCH net-next 0/9] devlink: remove the wait-for-references on unregister patchwork-bot+netdevbpf
2023-01-06 15:49 ` Jiri Pirko
2023-01-06 17:06 ` Jacob Keller
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