Re: Fwd: Re: e1000 1sec latency problem

From: Martin Rogge
Date: Sat Feb 09 2008 - 15:02:55 EST

On Saturday 09 February 2008 11:07:26 Martin Rogge wrote:
> Hi,
>
> I am not so familiar with the various mailing lists and missed out on
> e1000-devel@xxxxxxxxxxxxxxxxxxxxx the first time. Please cc me on any
> replies.
>
> I am looking for help with either making the e1000e driver work on my
> Thinkpad T60 or fixing the 1s latency issue with e1000.
>
> To be honest, I do not understand why the e1000e driver failed to recognize
> the NIC when I tried. At least, I noticed the correct device ID is defined
> in drivers/net/e1000e/hw.h:
>
> #define E1000_DEV_ID_82573L 0x109A
>
> Any help is appreciated.
>
> Thanks,
>
> Martin
>
> ---------- Forwarded Message ----------
>
> Subject: Re: e1000 1sec latency problem
> Date: Thursday 07 February 2008
> From: Martin Rogge <marogge@xxxxxxxxxxxxx>
> To: linux-kernel@xxxxxxxxxxxxxxx
>
> Pavel Machek wrote:
> > Hi!
> >
> > I have the famous e1000 latency problems:
>
> Hi, I have the same problem with my Thinkpad T60.
>
> root@zorro:~# ping arnold
> PING arnold (192.168.158.6) 56(84) bytes of data.
> 64 bytes from arnold (192.168.158.6): icmp_seq=1 ttl=64 time=49.7 ms
> 64 bytes from arnold (192.168.158.6): icmp_seq=2 ttl=64 time=0.438 ms
> 64 bytes from arnold (192.168.158.6): icmp_seq=3 ttl=64 time=1000 ms
> 64 bytes from arnold (192.168.158.6): icmp_seq=4 ttl=64 time=0.970 ms
> 64 bytes from arnold (192.168.158.6): icmp_seq=5 ttl=64 time=885 ms
> 64 bytes from arnold (192.168.158.6): icmp_seq=6 ttl=64 time=0.484 ms
> 64 bytes from arnold (192.168.158.6): icmp_seq=7 ttl=64 time=529 ms
> 64 bytes from arnold (192.168.158.6): icmp_seq=8 ttl=64 time=1.02 ms
> 64 bytes from arnold (192.168.158.6): icmp_seq=9 ttl=64 time=149 ms
> 64 bytes from arnold (192.168.158.6): icmp_seq=10 ttl=64 time=0.549 ms
> 64 bytes from arnold (192.168.158.6): icmp_seq=11 ttl=64 time=0.829 ms
>
> --- arnold ping statistics ---
> 11 packets transmitted, 11 received, 0% packet loss, time 9999ms
> rtt min/avg/max/mdev = 0.438/238.113/1000.967/365.279 ms, pipe 2
> root@zorro:~# uname -a
> Linux zorro 2.6.24 #6 SMP PREEMPT Sun Feb 3 18:27:48 CET 2008 i686 Intel(R)
> Core(TM)2 CPU T7200 @ 2.00GHz GenuineIntel GNU/Linux
> root@zorro:~# lspci -vvv

[stuff deleted]

> Unfortunately the e1000e driver is not an option as it will not detect the
> NIC:
>
> ----from dmesg with e1000 compiled in:
> Intel(R) PRO/1000 Network Driver - version 7.3.20-k2-NAPI
> Copyright (c) 1999-2006 Intel Corporation.
> ACPI: PCI Interrupt 0000:02:00.0[A] -> GSI 16 (level, low) -> IRQ 16
> PCI: Setting latency timer of device 0000:02:00.0 to 64
> e1000: 0000:02:00.0: e1000_probe: (PCI Express:2.5Gb/s:Width x1)
> 00:15:58:c3:3a:71
> e1000: eth0: e1000_probe: Intel(R) PRO/1000 Network Connection
>
> ----from dmesg with e1000e compiled in:
> e1000e: Intel(R) PRO/1000 Network Driver - 0.2.0
> e1000e: Copyright (c) 1999-2007 Intel Corporation.
>
> Any pointers?
>
> Thanks,
>
> Martin
>
>
>
> -------------------------------------------------------

Just for the records, I googled the following solution for the Lenovo T60:

(a) use the e1000 driver
(b) if compiling as a module, add the following parameter to modprobe.conf:
options e1000 RxIntDelay=5
(c) if compiling a static driver, use the following patch (based on 2.6.24):

--- e1000_param.c.orig 2008-01-24 23:58:37.000000000 +0100
+++ e1000_param.c 2008-02-09 20:42:23.000000000 +0100
@@ -158,7 +158,7 @@
* Valid Range: 0-65535
*/
E1000_PARAM(RxIntDelay, "Receive Interrupt Delay");
-#define DEFAULT_RDTR 0
+#define DEFAULT_RDTR 5
#define MAX_RXDELAY 0xFFFF
#define MIN_RXDELAY 0

After reboot, the average ping time is still factor 10 worse than it should
be, but it stays below 2 ms (which is a remarkable improvement compared to
1000 ms).

Martin
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