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
