From: Stefano Brivio <sbrivio@redhat.com>
To: aerosouund <aerosound161@gmail.com>
Cc: passt-dev@passt.top, eperezma@redhat.com
Subject: Re: [PATCH 0/7] Add vhost-net kernel support to pasta
Date: Thu, 17 Sep 2026 21:36:49 +0200 (CEST) [thread overview]
Message-ID: <20260917213648.6093b5fe@elisabeth> (raw)
In-Reply-To: <20260904212826.41027-1-aerosound161@gmail.com>
On Sat, 5 Sep 2026 00:28:19 +0300
aerosouund <aerosound161@gmail.com> wrote:
> [...]
>
> The changes reliably yield a roughly 2x speedup on the TX path (container
> to host).
>
> Numbers were obtained through iperf3 with the following methodology and
> results:
>
> Pasta command:
> ./pasta -f --runas 0:0 --map-guest-addr 192.168.0.5
> --vhost-kernel on --config-net 2729785
>
> Host:
> iperf3 -s1J
>
> Container:
> iperf3 -c 192.168.0.5 -t 10 -P4 -l 1M -w 32M -i1
>
> With --vhost-kernel on:
>
> [SUM] 0.00-10.00 sec 1.36 GBytes 1.17 Gbits/sec 3643 sender
> [SUM] 0.00-10.00 sec 1.16 GBytes 999 Mbits/sec receiver
>
> With --vhost-kernel off:
>
> [SUM] 0.00-10.00 sec 700 MBytes 587 Mbits/sec 3556 sender
> [SUM] 0.00-10.10 sec 495 MBytes 411 Mbits/sec receiver
Not a review and not a real test but I just quickly ran (once) the usual
perf/pasta_tcp tests with and without this series. Baseline:
> pasta: throughput and latency (connections via tap)
Throughput in Gbps, latency in µs, 2 threads at 3.6 GHz
MTU: | 1500B | 4000B | 16384B | 65520B |
|--------|--------|--------|--------|
TCP throughput over IPv6: ns to host | 2.7 | 4.2 | 4.5 | 18.7 |
TCP RR latency over IPv6: ns to host | - | - | - | 24 |
TCP CRR latency over IPv6: ns to host | - | - | - | 84 |
|--------|--------|--------|--------|
TCP throughput over IPv4: ns to host | 2.5 | 4.2 | 2.8 | 16.8 |
TCP RR latency over IPv4: ns to host | - | - | - | 25 |
TCP CRR latency over IPv4: ns to host | - | - | - | 72 |
|--------|--------|--------|--------|
TCP throughput over IPv6: host to ns | - | - | - | 14.2 |
TCP RR latency over IPv6: host to ns | - | - | - | 26 |
TCP CRR latency over IPv6: host to ns | - | - | - | 74 |
|--------|--------|--------|--------|
TCP throughput over IPv4: host to ns | - | - | - | 14.3 |
TCP RR latency over IPv4: host to ns | - | - | - | 28 |
TCP CRR latency over IPv4: host to ns | - | - | - | 82 |
'--------'--------'--------'--------'
with this series:
> pasta: throughput and latency (connections via tap)
Throughput in Gbps, latency in µs, 2 threads at 3.6 GHz
MTU: | 1500B | 4000B | 16384B | 65520B |
|--------|--------|--------|--------|
TCP throughput over IPv6: ns to host | 9.3 | 5.5 | 22.6 | 25.1 |
TCP RR latency over IPv6: ns to host | - | - | - | 35 |
TCP CRR latency over IPv6: ns to host | - | - | - | 93 |
|--------|--------|--------|--------|
TCP throughput over IPv4: ns to host | 9.3 | 5.2 | 10.9 | 24.8 |
TCP RR latency over IPv4: ns to host | - | - | - | 30 |
TCP CRR latency over IPv4: ns to host | - | - | - | 94 |
|--------|--------|--------|--------|
TCP throughput over IPv6: host to ns | - | - | - | 19.2 |
TCP RR latency over IPv6: host to ns | - | - | - | 33 |
TCP CRR latency over IPv6: host to ns | - | - | - | 90 |
|--------|--------|--------|--------|
TCP throughput over IPv4: host to ns | - | - | - | 17.4 |
TCP RR latency over IPv4: host to ns | - | - | - | 35 |
TCP CRR latency over IPv4: host to ns | - | - | - | 86 |
'--------'--------'--------'--------'
...latency increases a little but it still looks pretty good to me.
Throughput wise, for higher MTUs it's definitely an improvement in both
directions, and for lower MTUs we even hit 4x increases, that's quite
impressive.
I haven't checked if we need to tweak iperf3 parameters (or our buffers?)
to make this scale for large MTUs, but I guess that might be the case.
--
Stefano
prev parent reply other threads:[~2026-09-17 19:36 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-04 21:28 aerosouund
2026-09-04 21:28 ` [PATCH 1/7] tap: Move the tap_hdr file to a separate file aerosouund
2026-09-05 1:52 ` David Gibson
2026-09-09 8:47 ` Laurent Vivier
2026-09-09 9:10 ` David Gibson
2026-09-09 9:42 ` Laurent Vivier
2026-09-04 21:28 ` [PATCH 2/7] conf: Add context fields, epoll types and --vhost-kernel flag to pasta aerosouund
2026-09-09 12:35 ` Laurent Vivier
2026-09-12 10:57 ` Ammar Yasser
2026-09-14 6:56 ` Laurent Vivier
2026-09-04 21:28 ` [PATCH 3/7] virtio: Add the pasta vhost-net interface and implementation aerosouund
2026-09-09 15:13 ` Laurent Vivier
2026-09-04 21:28 ` [PATCH 4/7] tap: Implement the pasta vhost-net from-guest path aerosouund
2026-09-04 21:28 ` [PATCH 5/7] tap, tcp, udp: Prepare the to-guest path for vhost-net aerosouund
2026-09-04 21:28 ` [PATCH 6/7] tap: Implement the pasta vhost-net to-guest path aerosouund
2026-09-16 14:00 ` Laurent Vivier
2026-09-04 21:28 ` [PATCH 7/7] tap/tcp: Replace tcp_payload_used with a ring buffer style index aerosouund
2026-09-16 14:29 ` Laurent Vivier
2026-09-05 16:25 ` [PATCH 2/7] conf: Add context fields, epoll types and --vhost-kernel flag to pasta aerosouund
2026-09-05 16:25 ` [PATCH 3/7] virtio: Add the pasta vhost-net interface and implementation aerosouund
2026-09-05 16:25 ` [PATCH 4/7] tap: Implement the pasta vhost-net from-guest path aerosouund
2026-09-05 16:25 ` [PATCH 7/7] tap/tcp: Replace tcp_payload_used with a ring buffer style index aerosouund
2026-09-17 19:36 ` Stefano Brivio [this message]
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