Re: [EXT] Re: [PATCH net-next 3/5] net: mvpp2: cls: Use RSS contexts to handle RSS tables

[Matteo Croce]

On Wed, May 20, 2020 at 1:11 PM Russell King - ARM Linux admin
<linux@xxxxxxxxxxxxxxx> wrote:
>
> On Tue, May 19, 2020 at 07:05:34PM +0200, Matteo Croce wrote:
> > On Tue, 19 May 2020 12:05:20 +0200
> > Matteo Croce <mcroce@xxxxxxxxxx> wrote:
> >
> > Hi,
> >
> > The patch seems to work. I'm generating traffic with random MAC and IP
> > addresses, to have many flows:
> >
> > # tcpdump -tenni eth2
> > 9a:a9:b1:3a:b1:6b > 00:51:82:11:22:02, ethertype IPv4 (0x0800), length 60: 10.0.0.4.0 > 192.168.0.4.0: UDP, length 12
> > 9e:92:fd:f8:7f:0a > 00:51:82:11:22:02, ethertype IPv4 (0x0800), length 60: 10.0.0.4.0 > 192.168.0.4.0: UDP, length 12
> > 66:b7:11:8a:c2:1f > 00:51:82:11:22:02, ethertype IPv4 (0x0800), length 60: 10.0.0.1.0 > 192.168.0.1.0: UDP, length 12
> > 7a:ba:58:bd:9a:62 > 00:51:82:11:22:02, ethertype IPv4 (0x0800), length 60: 10.0.0.1.0 > 192.168.0.1.0: UDP, length 12
> > 7e:78:a9:97:70:3a > 00:51:82:11:22:02, ethertype IPv4 (0x0800), length 60: 10.0.0.2.0 > 192.168.0.2.0: UDP, length 12
> > b2:81:91:34:ce:42 > 00:51:82:11:22:02, ethertype IPv4 (0x0800), length 60: 10.0.0.2.0 > 192.168.0.2.0: UDP, length 12
> > 2a:05:52:d0:d9:3f > 00:51:82:11:22:02, ethertype IPv4 (0x0800), length 60: 10.0.0.3.0 > 192.168.0.3.0: UDP, length 12
> > ee:ee:47:35:fa:81 > 00:51:82:11:22:02, ethertype IPv4 (0x0800), length 60: 10.0.0.3.0 > 192.168.0.3.0: UDP, length 12
> >
> > This is the default rate, with rxhash off:
> >
> > # utraf eth2
> > tx: 0 bps 0 pps rx: 397.4 Mbps 827.9 Kpps
> > tx: 0 bps 0 pps rx: 396.3 Mbps 825.7 Kpps
> > tx: 0 bps 0 pps rx: 396.6 Mbps 826.3 Kpps
> > tx: 0 bps 0 pps rx: 396.5 Mbps 826.1 Kpps
> >
> >     PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
> >       9 root      20   0       0      0      0 R  99.7   0.0   7:02.58 ksoftirqd/0
> >      15 root      20   0       0      0      0 S   0.0   0.0   0:00.00 ksoftirqd/1
> >      20 root      20   0       0      0      0 S   0.0   0.0   2:01.48 ksoftirqd/2
> >      25 root      20   0       0      0      0 S   0.0   0.0   0:32.86 ksoftirqd/3
> >
> > and this with rx hashing enabled:
> >
> > # ethtool -K eth2 rxhash on
> > # utraf eth2
> > tx: 0 bps 0 pps rx: 456.4 Mbps 950.8 Kpps
> > tx: 0 bps 0 pps rx: 458.4 Mbps 955.0 Kpps
> > tx: 0 bps 0 pps rx: 457.6 Mbps 953.3 Kpps
> > tx: 0 bps 0 pps rx: 462.2 Mbps 962.9 Kpps
> >
> >     PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
> >      20 root      20   0       0      0      0 R   0.7   0.0   2:02.34 ksoftirqd/2
> >      25 root      20   0       0      0      0 S   0.3   0.0   0:33.25 ksoftirqd/3
> >       9 root      20   0       0      0      0 S   0.0   0.0   7:52.57 ksoftirqd/0
> >      15 root      20   0       0      0      0 S   0.0   0.0   0:00.00 ksoftirqd/1
> >
> >
> > The throughput doesn't increase so much, maybe we hit an HW limit of
> > the gigabit port. The interesting thing is how the global CPU usage
> > drops from 25% to 1%.
> > I can't explain this, it could be due to the reduced contention?
>
> Hi Matteo,
>
> Can I take that as a Tested-by ?
>
> Thanks.
>
> --
> RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
> FTTC for 0.8m (est. 1762m) line in suburbia: sync at 13.1Mbps down 424kbps up
>

Tested-by: Matteo Croce <mcroce@xxxxxxxxxx>

probably also:

Reported-by: Matteo Croce <mcroce@xxxxxxxxxx>

Thanks,
-- 
Matteo Croce
per aspera ad upstream