From: Oliver Neukum <oneukum@suse.de>
To: Dave Taht <dave.taht@gmail.com>
Cc: cerowrt-devel@lists.bufferbloat.net
Subject: Re: [Cerowrt-devel] debloating the Pi, maybe not.
Date: Mon, 26 Nov 2012 16:10:43 +0100 [thread overview]
Message-ID: <6215800.d6FWbLqba3@linux-lqwf.site> (raw)
In-Reply-To: <CAA93jw5FYhjbMFGJUOdZ=iRAvyDjYeVVQaZSZARnb6V6kChMBA@mail.gmail.com>
On Friday 23 November 2012 17:43:24 Dave Taht wrote:
> I was donated a raspberry pi in cambridge and got it booted today.
> It's a very cool
> box, an arm6, running debian, with hard floating point, and getting a complete
> development environment running, getting it to do mesh networking,
> graphics, apache, etc, on a 16GB SD card, was a breeze.
>
> But as for network performance:
>
> It only comes up at 100Mbit, and as noted elsewhere the ethernet chip
> is hooked up over USB.
>
> dmesg
>
> [3.078644] smsc95xx 1-1.1:1.0: eth0: register 'smsc95xx' at
> usb-bcm2708_usb-1.1, smsc95xx USB 2.0 Ethernet, b8:27:eb:18:fc:ac
>
> The best the 3.2 kernel based networking can do is about 75Mbit/sec.
> This eats 68% of cpu in the "system" (sy in top) and 30% in si (system
> interrupt)
Wow. What did you do to saturate the system like this? Blow empty
UDP packages into the net?
> I had had some hope of this being a good box to put some test tools on,
> but with performance like this, I am back to leveraging the mips stuff.
>
> That said, I do intend to poke at the driver and update to 3.6 when
> I get a chance, since we have patches lying around for both this
> chip and the usbnet code.
Nothing for performance in the mean time. Note that we don't try to
do interrupt mitigation in usbnet.
Regards
Oliver
next prev parent reply other threads:[~2012-11-26 15:10 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-23 16:43 Dave Taht
2012-11-26 15:10 ` Oliver Neukum [this message]
2012-11-26 15:29 ` Dave Taht
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