On Sun, Dec 28, 2014 at 08:25:40AM -0800, Dave Taht wrote:

On Sun, Dec 28, 2014 at 6:57 AM, Beniamino Galvani [off-list ref] wrote:

quoted

Add support for Byte Queue Limits to the STMicro MAC driver.

Thank you!

quoted

Tested on a Amlogic S805 Cortex-A5 board, where the use of BQL
slightly decreases the ping latency from ~10ms to ~3ms when the
100Mbps link is saturated by TCP streams. No difference is
observed at 1Gbps.

I see the plural. With TSQ in place it is hard (without something like
the rrul test driving multiple streams) to drive a driver to
saturation with small numbers of flows. This was with pfifo_fast, not
sch_fq, at 100mbit?

Hi Dave,

yes, this was with pfifo_fast and I used 4 iperf TCP streams. The total
throughput didn't seem to increase adding more streams.

Can this board actually drive a full gigabit in the first place? Until
now most of the low end arm boards I have seen only came with
a 100mbit mac, and the gig ones lacking offloads seemed to peak
out at about 600mbit.

I measured a throughput of 650mbit in rx and 600mbit in tx.

Under my christmas tree landed a quad core A5 (odroid-c1), also an
xgene and zedboard - both of the latter are a-needing BQL,
and I haven't booted the udroid yet. Hopefully it is the
same driver you just improved.

I'm using the odroid-c1 too, with this tree based on the recent
Amlogic mainline work:

  https://github.com/bengal/linux/tree/meson8b

Unfortunately at the moment the support for the board is very basic
(for example, SMP is not working yet) but it's enough to do some NIC
tests.

Beniamino