From: Thomas Karlsson <thomas.karlsson@paneda.se>
To: Jakub Kicinski <kuba@kernel.org>
Cc: "davem@davemloft.net" <davem@davemloft.net>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
<thomas.karlsson@paneda.se>
Subject: Re: Hardcoded multicast queue length in macvlan.c driver causes poor multicast receive performance
Date: Wed, 25 Nov 2020 23:15:39 +0100 [thread overview]
Message-ID: <956c4fca-2a54-97cb-5b4c-3a286743884b@paneda.se> (raw)
In-Reply-To: <20201125100710.7e766d7e@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
On 2020-11-25 19:07, Jakub Kicinski wrote:
> On Wed, 25 Nov 2020 18:12:34 +0100 Thomas Karlsson wrote:
>>>> For this reason I would like to know if you would consider
>>>> merging a patch using the module_param(...) variant instead?
>>>>
>>>> I would argue that this still makes the situation better
>>>> and resolves the packet-loss issue, although not necessarily
>>>> in an optimal way. However, The upside of being able to specify the
>>>> parameter on a per macvlan interface level instead of globally is not
>>>> that big in this situation. Normally you don't use that much
>>>> multicast anyway so it's a parameter that only will be touched by
>>>> a very small user base that can understand and handle the implications
>>>> of such a global setting.
>>>
>>> How about implementing .changelink in macvlan? That way you could
>>> modify the macvlan device independent of Docker?
>>>
>>> Make sure you only accept changes to the bc queue len if that's the
>>> only one you act on.
>>>
>>
>> Hmm, I see. You mean that docker can create the interface and then I can
>> modify it afterwards? That might be a workaround but I just submitted
>> a patch (like seconds before your message) with the module_param() option
>> and this was very clean I think. both in how little code that needed to be
>> changed and in how simple it is to set the option in the target environment.
>>
>> This is my first time ever attemting a contribution to the kernel so
>> I'm quite happy to keep it simple like that too :)
>
> Module params are highly inflexible, we have a general policy not
> to accept them in the netdev world.
>
I see, although the current define seems even less flexible :)
Although, I might not have fully understood the .changelink you suggest.
Is it via the ip link set ... command? Or is there a way to set the parameters
in a more "raw" form that does not require a patch to iproute2 with parameter parsing,
error handing, man pages updates, etc. I feel that I'm getting in over my head here.
I appreciate your feedback!
> There should even be a check> in our patchwork which should fail here, but it appears that the patch
> did not apply in the first place:
>
> https://patchwork.kernel.org/project/netdevbpf/patch/385b9b4c-25f5-b507-4e69-419883fa8043@paneda.se/
>
> Make sure you're developing on top of this tree:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/
>
Right, thanks! It's a bit of a learning curve. I had incorrectly done the work on top of torvalds/linux
next prev parent reply other threads:[~2020-11-25 22:16 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <485531aec7e243659ee4e3bb7fa2186d@paneda.se>
2020-11-23 14:22 ` Hardcoded multicast queue length in macvlan.c driver causes poor multicast receive performance Thomas Karlsson
2020-11-23 22:30 ` Jakub Kicinski
2020-11-25 12:51 ` Thomas Karlsson
2020-11-25 16:57 ` [PATCH] macvlan: Support for high multicast packet rate Thomas Karlsson
2020-11-25 21:55 ` [PATCH net-next v2] " Thomas Karlsson
2020-11-25 16:58 ` Hardcoded multicast queue length in macvlan.c driver causes poor multicast receive performance Jakub Kicinski
2020-11-25 17:12 ` Thomas Karlsson
2020-11-25 18:07 ` Jakub Kicinski
2020-11-25 22:15 ` Thomas Karlsson [this message]
2020-11-25 23:01 ` Jakub Kicinski
2020-11-26 20:00 ` Thomas Karlsson
2020-11-27 17:27 ` Jakub Kicinski
2020-11-27 23:13 ` Thomas Karlsson
2020-11-30 14:00 ` [PATCH net-next v3] macvlan: Support for high multicast packet rate Thomas Karlsson
2020-12-01 19:11 ` Jakub Kicinski
2020-12-02 11:28 ` Thomas Karlsson
2020-12-02 16:44 ` Jakub Kicinski
2020-11-30 14:23 ` [PATCH iproute2-next v1] iplink macvlan: Added bcqueuelen parameter Thomas Karlsson
2020-12-10 16:07 ` Thomas Karlsson
2020-12-11 0:36 ` Jakub Kicinski
2020-12-02 18:49 ` [PATCH net-next v4] macvlan: Support for high multicast packet rate Thomas Karlsson
2020-12-03 16:20 ` Jakub Kicinski
2020-12-03 16:53 ` Thomas Karlsson
2020-12-14 10:42 ` [PATCH iproute2-next v2] iplink:macvlan: Added bcqueuelen parameter Thomas Karlsson
2020-12-14 17:03 ` David Ahern
2020-12-14 17:50 ` Thomas Karlsson
2020-12-16 4:07 ` David Ahern
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