[arch-general] [kernel26 >= .30 + e100] Slow ethernet

[David C. Rankin]

On Tuesday 22 September 2009 02:54:26 am Gerhard Brauer wrote:
> Hi,
> 
> since 2.6.30.x (i could not exactly say if also with the latest
> 2.6.29.x) stock kernels i have a terrible slow ethernet transfer rate on
> my old Thinkpad T22 (Intel EtherExpress PRO/100 SP, module e100).
> 
> Normal transfer rate ex. to a mirror is for me ~700Kb/s but i got only
> ~80-90 Kb/s. And a bunch of RX overruns and frame errors.
> 
> I could solve it by following workarounds:
> a) Disable ACPI (acpi=off), but this is the ugliest workaround.
> 
> b) When i generate CPU-Load (ex: dd if=/dev/zero of=/dev/null) the
> transfer rate goes immediately up to normal and the RX error rate
> increasing stops. Stopping the dd the rate goes down again. So i thought
> it could be a timer/IRQ problem.
> I tried different acpi= and pci= kernel parameters without success. Also
> tried to isolate the Ethernet device to a non-shared IRQ.
> 
> c) Current working solution is if i use nohz=off as kernel param.
> But testing with an 2.6.28 kernel i have installed on this TP there is
> CONFIG_NO_HZ=y also set (diff is only that this kernel has
> CONFIG_HZ=1000 and 2.6.30/31 CONFIG_HZ=300, but AFAIK if bootet with
> NOHZ these settings are ignored (tickless)).
> 
> So there must be a signifikant change in >= 2.6.30 (tested 2.6.31 from
> testing also). Anyone has an idea to solve it without nohz parameter? I
> also could report it to LKML if this seems a bug (for me it is).
> 
> Regards
> 	Gerhard
> 

Gerhard,

	I can't help, but I can confirm I'm trying to solve a similar issue with my 
Toshiba laptop (Atheros wireless) where the wireless network (LAN) transfers 
slowed from 3.1MB/s to 201kB/s. So far it looks like a time (clock) issue on 
my box, but I'm still trying to figure out exactly what is happening.

-- 
David C. Rankin, J.D.,P.E.
Rankin Law Firm, PLLC
510 Ochiltree Street
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