Message-ID: <20190206103645.GA2482@ingrassia.epigenesys.com>
Date:   Wed, 6 Feb 2019 11:36:45 +0100
From:   Emiliano Ingrassia <ingrassia@...genesys.com>
To:     Martin Blumenstingl <martin.blumenstingl@...glemail.com>,
        Simon Huelck <simonmail@....de>
Cc:     Gpeppe.cavallaro@...com, alexandre.torgue@...com,
        linux-amlogic@...ts.infradead.org, netdev@...r.kernel.org
Subject: Re: stmmac / meson8b-dwmac

Hi Martin, Hi Simon,

On Mon, Feb 04, 2019 at 03:34:41PM +0100, Martin Blumenstingl wrote:
> On Thu, Jan 17, 2019 at 10:23 PM Simon Huelck <simonmail@....de> wrote:
> [...]
> > >> I got problems with my ODROID c2 running on 4.19.16 ( and some releases
> > >> earlier ). the stmmac / dwmac driver doesnt provide the 800M/900M
> > >> performance that i was used to earlier.
> > >>

Simon, did you ever reach 1 Gbps full duplex speed?
If yes, what was the kernel version did you use?

> > >>
> > >> Now im stuck near 550M/600M in the same environment. but what really
> > >> confuses me that duplex does hurt even more.
> > > interesting that you see this on the Odroid-C2 as well.
> > > previously I have only observed it on an Odroid-C1
> > >
> > >> PC --- VLAN3 --> switch --VLAN3--> ODROID
> > >>
> > >> NAS <-- VLAN1 -- switch <-- VLAN1-- ODROID
> > >>
> > >>
> > >> this means when im doing a iperf from PC to NAS, that my ODROID has load
> > >> on RX/TX same time (duplex). this shouldnt be an issue , all is 1GBits
> > >> FD. And in the past that wasnt an issue.
> +Cc Emiliano who has seen a similar duplex issue on his Odroid-C1: [0]
> (please note that all kernels prior to v5.1 with the pending patches
> from [1] applied are only receiving data on RXD0 and RXD1 but not on
> RXD2 and RXD3)
>
> Emiliano, can you confirm the duplex issue observed by Simon is
> similar to the one you see on your Odroid-C1?
>

It could be but, if I understand correctly, Simon is limited in
speed also in half duplex transmission (~550/600 Mbps), while we can
reach at least 900 Mbps.

> > >>
> > >>
> > >> Now what happens:
> > >>
> > >> - benchmark between PC - ODROID is roughly 550M
> > >>
> > >> - benchmark between NAS - ODROID is roughly 550M
> > >>
> > >> - benchmark between PC - NAS is only around 300M
> > >>
> > >>
> > >> and like i said i was easliy able to hit 800 or even 900M to my NAS
> > >> earlier. I applied some .dtb fixes for interrupt levels for the
> > >> meson-gx.dtsi and meson-gxbb-odroid-c2.dtb, which will be mainlined ,
> > >> but the effect stayed identical.
> > > good that you have the interrupt patches already applied
> > > I believe it don't fix any performance issues - it's a fix for the
> > > Ethernet controller seemingly getting "stuck" (not processing data
> > > anymore). however, that already rules out one potential issue
> > >
> > >> are you aware of this problem ? Earlier kernel versions were all
> > >> perfectly fine and i stepped ( self compiled) kernel through all major
> > >> releases since odroid c2 was mainlined.
> Guiseppe, Alexandre: what kind of data do you need from us if we see
> the speeds drop (in both directions) when we send and receive at the
> same time?
>
> [...]
> > the problem is that i dont have these kernel sources anymore :-(. but i
> > can provide some testing and numbers. maybe i dig if i got these kernel
> > configs somewhere around but i did not change much during migrating
> do you remember the kernel version where it worked fine?
>
> > im using a zyxel gs1900-8 switch and a qnap ts231p , and as i said i
> > didnt change my setup. i was able to hit 100MByte/s from my NAS , so
> > close to the benchmarks of 900MBit/s
> I typically only do small transfers or I have traffic only in one direction.
> thus it's likely that I missed this in my own tests
>
>
> Regards
> Martin
>
>
> [0] http://lists.infradead.org/pipermail/linux-amlogic/2018-December/009679.html
> [1] https://patchwork.kernel.org/cover/10744905/

Regards,

Emiliano

Powered by blists - more mailing lists