From: Jakub Kicinski <kuba@kernel.org>
To: Etienne Champetier <champetier.etienne@gmail.com>
Cc: netdev@vger.kernel.org
Subject: Re: Multicast packet reordering
Date: Fri, 2 Dec 2022 10:34:29 -0800 [thread overview]
Message-ID: <20221202103429.1887d586@kernel.org> (raw)
In-Reply-To: <e0f9fb60-b09c-30ad-0670-aa77cc3b2e12@gmail.com>
On Thu, 1 Dec 2022 23:45:53 -0500 Etienne Champetier wrote:
> Using RPS fixes the issue, but to make it short:
> - Is it expect to have multicast packet reordering when just tuning buffer sizes ?
> - Does it make sense to use RPS to fix this issue / anything else / better ?
> - In the case of 2 containers talking using veth + bridge, is it better to keep 1 queue
> and set rps_cpus to all cpus, or some more complex tuning like 1 queue per cpu + rps on 1 cpu only ?
Yes, there are per-cpu queues in various places to help scaling,
if you don't pin the sender to one CPU and it gets moved you can
understandably get reordering w/ UDP (both on lo and veth).
As Andrew said that's considered acceptable.
Unfortunately it's one of those cases where we need to relax
the requirements / stray from the ideal world if we want parallel
processing to not suck..
next prev parent reply other threads:[~2022-12-02 18:34 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-02 4:45 Multicast packet reordering Etienne Champetier
2022-12-02 13:46 ` Andrew Lunn
2022-12-02 15:32 ` Etienne Champetier
2022-12-02 18:34 ` Jakub Kicinski [this message]
2022-12-02 20:09 ` Etienne Champetier
2022-12-02 21:39 ` Jakub Kicinski
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