Re: peculiar problem with 2.6, 8139too + ACPI

From: Len Brown
Date: Mon May 17 2004 - 13:29:09 EST

On Mon, 2004-05-17 at 06:30, Robert Fendt wrote:
> On 14 May 2004 21:36:38 -0400
> Len Brown <len.brown@xxxxxxxxx> wrote:
>
> > If the 8139too has statistics counters showing if it gets
> > RX buffer over-runs, that would be interseting to observe.
>

> a) with 'processor' loaded
>
> robert@betazed:~$ wget http://download.sourcemage.org/iso/smgl-i386-2.6.5-20040414.iso.bz2
> --12:27:16-- http://download.sourcemage.org/iso/smgl-i386-2.6.5-20040414.iso.bz2
> => `smgl-i386-2.6.5-20040414.iso.bz2'
> Resolving download.sourcemage.org... 152.2.210.81
> Connecting to download.sourcemage.org[152.2.210.81]:80... connected.
> HTTP request sent, awaiting response... 200 OK
> Length: 142,065,569 [text/plain]
>
> 0% [ ] 202,609 2.30K/s ETA 10:17:41
>
>
> robert@betazed:~$ /sbin/ifconfig
> eth0 Link encap:Ethernet HWaddr 00:0C:6E:8A:DD:BA
> inet addr:129.217.168.125 Bcast:129.217.168.255 Mask:255.255.255.0
> inet6 addr: fe80::20c:6eff:fe8a:ddba/64 Scope:Link
> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> RX packets:933 errors:117 dropped:212 overruns:117 frame:0

BINGO

There may be a way to get more detailed stats out of the driver with
netstat or something, Jeff would know.

> TX packets:638 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:622241 (607.6 KiB) TX bytes:54355 (53.0 KiB)
> Interrupt:5 Base address:0xc800
>
>
> b) without 'processor' loaded
>
> robert@betazed:~$ wget http://download.sourcemage.org/iso/smgl-i386-2.6.5-20040414.iso.bz2
> --11:29:17-- http://download.sourcemage.org/iso/smgl-i386-2.6.5-20040414.iso.bz2
> => `smgl-i386-2.6.5-20040414.iso.bz2.2'
> Resolving download.sourcemage.org... 152.2.210.81
> Connecting to download.sourcemage.org[152.2.210.81]:80... connected.
> HTTP request sent, awaiting response... 200 OK
> Length: 142,065,569 [text/plain]
>
> 3% [=> ] 5,526,132 514.93K/s
>
> robert@betazed:~$ /sbin/ifconfig
> eth0 Link encap:Ethernet HWaddr 00:0C:6E:8A:DD:BA
> inet addr:129.217.168.125 Bcast:129.217.168.255 Mask:255.255.255.0
> inet6 addr: fe80::20c:6eff:fe8a:ddba/64 Scope:Link
> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
> RX packets:4187 errors:0 dropped:0 overruns:0 frame:0
> TX packets:2313 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:1000
> RX bytes:5904292 (5.6 MiB) TX bytes:149285 (145.7 KiB)
> Interrupt:5 Base address:0xc800
>
>
> One additional problem in debugging this is that it seems to be
> depending on the local network topology, since I somehow cannot
> reproduce it when downloading from machines on the LAN or when I have a
> slow downstream connection (e.g. DSL).

Probably something to do with packet arrival time and the ability of the
system to think it is idle. What topology does it fail with?

> > It would also be interesting to know if you see the problem
> > more frequently when running on battery power, since some
> > systems have higher c-state exit latency when on battery.
>
> Hmmm, I cannot see a difference between battery and ac. I will look into
> it a bit more, though.

Does
cat /proc/acpi/processor/CPU0/power
show any C3 usage?

This could be either an ACPI issue -- we may enter C3 when there really
isn't enough time to enter and exit C3 w/o thrashing the system; AND/OR
a NIC problem where the driver/device is prone to over-run errors
when the latency to memory is high.

I think we're having a similar problem with the ipw2100. it would
be interesting if you plugged an e100 into the failing config if
it fails the same way.

-Len


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