From: Stefano Brivio <sbrivio@redhat.com>
To: Laurent Vivier <lvivier@redhat.com>
Cc: passt-dev@passt.top
Subject: Re: Testing vhost-user with "virtio-net: tweak for better TX performance in NAPI mode"
Date: Tue, 18 Mar 2025 17:33:34 +0100 [thread overview]
Message-ID: <20250318173334.0ab108c8@elisabeth> (raw)
In-Reply-To: <2f3fa74f-523d-4c03-bffb-8d154c40261b@redhat.com>
On Tue, 18 Mar 2025 12:07:09 +0100
Laurent Vivier <lvivier@redhat.com> wrote:
> ____ The results with a 6.14-rc7 + e13b6da7045f:
Thanks for checking!
> From guest:
>
> iperf3 -c 10.6.68.254 -P2 -Z -t5 -l 1M -w 16M
> [SUM] 0.00-5.00 sec 14.8 GBytes 25.4 Gbits/sec 0 sender
> [SUM] 0.00-5.01 sec 14.8 GBytes 25.4 Gbits/sec receiver
>
> From host:
>
> iperf3 -c localhost -P2 -Z -t5 -p 10001 -l 1M -w 16M
> [SUM] 0.00-5.00 sec 28.5 GBytes 48.9 Gbits/sec 0 sender
> [SUM] 0.00-5.03 sec 28.4 GBytes 48.6 Gbits/sec receiver
>
> We have only a 2% improvement.
Ouch. :( Then there's something else... by the way, for reference, my
investigation back then stopped a bit after:
https://archives.passt.top/passt-dev/20241010090801.23da8bff@elisabeth/
that is, I tried zeroing pages "fast":
https://archives.passt.top/passt-dev/20241017021027.2ac9ea53@elisabeth/
but it didn't really change the asymmetry. I was getting the same
numbers you're getting now.
Whatever, I guess it's not so important, just... one day we should
figure it out. :)
--
Stefano
prev parent reply other threads:[~2025-03-18 16:33 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-18 11:07 Testing vhost-user with "virtio-net: tweak for better TX performance in NAPI mode" Laurent Vivier
2025-03-18 16:33 ` Stefano Brivio [this message]
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