RE: high latency on 82573L

From: Allan, Bruce W
Date: Thu Sep 02 2010 - 14:49:30 EST


On Wednesday, September 01, 2010 8:39 PM, Tony Jones wrote:
> Hi.
>
> Since commit 6f461f6c7c (e1000e: enable/disable ASPM L0s and L1 and
> ERT according to hardware errata) I'm seeing high latencies on my
> Thinkpad T60p.
>
> 02:00.0 Ethernet controller: Intel Corporation 82573L Gigabit
> Ethernet Controller Subsystem: Lenovo ThinkPad T60
> Flags: bus master, fast devsel, latency 0, IRQ 30
> Memory at ee000000 (32-bit, non-prefetchable) [size=128K]
> I/O ports at 3000 [size=32]
> Capabilities: [c8] Power Management version 2
> Capabilities: [d0] MSI: Enable+ Count=1/1 Maskable- 64bit+
> Capabilities: [e0] Express Endpoint, MSI 00
> Capabilities: [100] Advanced Error Reporting
> Capabilities: [140] Device Serial Number 00-1a-6b-ff-ff-6c-7e-a4
> Kernel driver in use: e1000e
>
> # uname -r
> 2.6.36-rc3-0-default
> # ping -c 20 192.168.1.1
> PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
> 64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=1.06 ms
> 64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=1007 ms
> 64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=698 ms
> 64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=198 ms
> 64 bytes from 192.168.1.1: icmp_seq=5 ttl=64 time=697 ms
> 64 bytes from 192.168.1.1: icmp_seq=6 ttl=64 time=1007 ms
> 64 bytes from 192.168.1.1: icmp_seq=7 ttl=64 time=690 ms
> 64 bytes from 192.168.1.1: icmp_seq=8 ttl=64 time=1007 ms
> 64 bytes from 192.168.1.1: icmp_seq=9 ttl=64 time=682 ms
> 64 bytes from 192.168.1.1: icmp_seq=10 ttl=64 time=1008 ms
> 64 bytes from 192.168.1.1: icmp_seq=11 ttl=64 time=1.03 ms
> 64 bytes from 192.168.1.1: icmp_seq=12 ttl=64 time=1007 ms
> 64 bytes from 192.168.1.1: icmp_seq=13 ttl=64 time=0.874 ms
> 64 bytes from 192.168.1.1: icmp_seq=14 ttl=64 time=1009 ms
> 64 bytes from 192.168.1.1: icmp_seq=15 ttl=64 time=1.72 ms
> 64 bytes from 192.168.1.1: icmp_seq=16 ttl=64 time=1006 ms
> 64 bytes from 192.168.1.1: icmp_seq=17 ttl=64 time=650 ms
> 64 bytes from 192.168.1.1: icmp_seq=18 ttl=64 time=1008 ms
> 64 bytes from 192.168.1.1: icmp_seq=19 ttl=64 time=642 ms
> 64 bytes from 192.168.1.1: icmp_seq=20 ttl=64 time=1643 ms
>
> --- 192.168.1.1 ping statistics ---
> 20 packets transmitted, 20 received, 0% packet loss, time 19063ms
> rtt min/avg/max/mdev = 0.874/698.661/1643.392/439.376 ms, pipe 2
>
> This is 2.6.36-rc3 yet commit 19833b5dff (e1000e: disable ASPM L1 on
> 82573) isn't having any effect for me.
>
> For our OpenSUSE 11.3 kernels (2.6.34 based), reverting just
> 6f461f6c7c
> solves the issue. For .36-rc3 reverting 6f461f6c7c plus of course
> 19833b5dff does the trick.
>
> I'm happy to perform any testing to help narrow this down. LMK.
>
> Tony

Please provide more verbose lspci output and include the PCI config
space, i.e. 'lspci -s 2:0.0 -vvv -xxx' after the driver is loaded,
your kernel .config and the full version number of the OpenSUSE
kernel. Are there any messages in the system log regarding disabling
ASPM L0s and/or L1 on that device?

I can understand the latency with the OpenSUSE 2.6.34-based kernels
assuming commit 19833b5dff is not present, but I do not understand
the latency with 2.6.36-rc3.

Thanks,
Bruce.
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