[Bloat] Fwd: [PATCH net-next v2] virtio_net: add support for Byte Queue Limits

[Dave Taht]

I am so happy to see this patch land finally!

---------- Forwarded message ---------
From: Jason Xing <kerneljasonxing at gmail.com>
Date: Mon, Jun 17, 2024, 8:48 AM
Subject: Re: [PATCH net-next v2] virtio_net: add support for Byte Queue
Limits
To: Jiri Pirko <jiri at resnulli.us>
Cc: <netdev at vger.kernel.org>, <davem at davemloft.net>, <edumazet at google.com>,
<kuba at kernel.org>, <pabeni at redhat.com>, <mst at redhat.com>, <
jasowang at redhat.com>, <xuanzhuo at linux.alibaba.com>, <
virtualization at lists.linux.dev>, <ast at kernel.org>, <daniel at iogearbox.net>, <
hawk at kernel.org>, <john.fastabend at gmail.com>, <dave.taht at gmail.com>, <
hengqi at linux.alibaba.com>


On Mon, Jun 17, 2024 at 5:15 PM Jiri Pirko <jiri at resnulli.us> wrote:
>
> Fri, Jun 14, 2024 at 11:54:04AM CEST, kerneljasonxing at gmail.com wrote:
> >Hello Jiri,
> >
> >On Thu, Jun 13, 2024 at 1:08 AM Jiri Pirko <jiri at resnulli.us> wrote:
> >>
> >> From: Jiri Pirko <jiri at nvidia.com>
> >>
> >> Add support for Byte Queue Limits (BQL).
> >>
> >> Tested on qemu emulated virtio_net device with 1, 2 and 4 queues.
> >> Tested with fq_codel and pfifo_fast. Super netperf with 50 threads is
> >> running in background. Netperf TCP_RR results:
> >>
> >> NOBQL FQC 1q:  159.56  159.33  158.50  154.31    agv: 157.925
> >> NOBQL FQC 2q:  184.64  184.96  174.73  174.15    agv: 179.62
> >> NOBQL FQC 4q:  994.46  441.96  416.50  499.56    agv: 588.12
> >> NOBQL PFF 1q:  148.68  148.92  145.95  149.48    agv: 148.2575
> >> NOBQL PFF 2q:  171.86  171.20  170.42  169.42    agv: 170.725
> >> NOBQL PFF 4q: 1505.23 1137.23 2488.70 3507.99    agv: 2159.7875
> >>   BQL FQC 1q: 1332.80 1297.97 1351.41 1147.57    agv: 1282.4375
> >>   BQL FQC 2q:  768.30  817.72  864.43  974.40    agv: 856.2125
> >>   BQL FQC 4q:  945.66  942.68  878.51  822.82    agv: 897.4175
> >>   BQL PFF 1q:  149.69  151.49  149.40  147.47    agv: 149.5125
> >>   BQL PFF 2q: 2059.32  798.74 1844.12  381.80    agv: 1270.995
> >>   BQL PFF 4q: 1871.98 4420.02 4916.59 13268.16   agv: 6119.1875
> >
> >I cannot get such a huge improvement when I was doing multiple tests
> >between two VMs. I'm pretty sure the BQL feature is working, but the
> >numbers look the same with/without BQL.
> >
> >VM 1 (client):
> >16 cpus, x86_64, 4 queues, the latest net-next kernel with/without
> >this patch, pfifo_fast, napi_tx=true, napi_weight=128
> >
> >VM 2 (server):
> >16 cpus, aarch64, 4 queues, the latest net-next kernel without this
> >patch, pfifo_fast
> >
> >What the 'ping' command shows to me between two VMs is : rtt
> >min/avg/max/mdev = 0.233/0.257/0.300/0.024 ms
> >
> >I started 50 netperfs to communicate the other side with the following
command:
> >#!/bin/bash
> >
> >for i in $(seq 5000 5050);
> >do
> >netperf -p $i -H [ip addr] -l 60 -t TCP_RR -- -r 64,64 > /dev/null 2>&1 &
> >done
> >
> >The results are around 30423.62 txkB/s. If I remove '-r 64 64', they
> >are still the same/similar.
>
> You have to stress the line by parallel TCP_STREAM instances (50 in my
> case). For consistent results, use -p portnum,locport to specify the
> local port.

Thanks. Even though the results of TCP_RR mode vary sometimes, I can
see a big improvement in the total value of those results under such
circumstances.
With BQL, the throughput is 2159.17
Without BQL, it's 1099.33

Please feel free to add the tag:
Tested-by: Jason Xing <kerneljasonxing at gmail.com>

Thanks,
Jason
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