e1000 1sec latency problem

[Pavel Machek <pavel@ucw.cz>]

Hi!

I have the famous e1000 latency problems:

64 bytes from 195.113.31.123: icmp_seq=68 ttl=56 time=351.9 ms
64 bytes from 195.113.31.123: icmp_seq=69 ttl=56 time=209.2 ms
64 bytes from 195.113.31.123: icmp_seq=70 ttl=56 time=1004.1 ms
64 bytes from 195.113.31.123: icmp_seq=71 ttl=56 time=308.9 ms
64 bytes from 195.113.31.123: icmp_seq=72 ttl=56 time=305.4 ms
64 bytes from 195.113.31.123: icmp_seq=73 ttl=56 time=9.8 ms
64 bytes from 195.113.31.123: icmp_seq=74 ttl=56 time=3.7 ms

...and they are still there in 2.6.25-git0. I had ethernet EEPROM
checksum problems, which I fixed by the update, but problems are not
gone.

irqpoll helps.

nosmp (which implies XT-PIC is being used) does not help.

 16:       1925          0   IO-APIC-fasteoi   ahci, yenta, uhci_hcd:usb2, eth0

Booting kernel with nosmp/ no yenta, no usb does not help.

Hmm, as expected, interrupt load on ahci (find /) makes latencies go
away.

It should be easily reproducible on x60 with latest bios, it is 100%
reproducible for me...
									Pavel
-- 
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