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 Nacogdoches, Texas 75961 Telephone: (936) 715-9333 Facsimile: (936) 715-9339 www.rankinlawfirm.com