Spontaneous Slowdowns on SMP System

[Donald Becker]

On Thu, 19 Aug 1999, Jim Morris wrote:

> I have a dual-processor system running the Linux 2.2.10 kernel.  I am
> using a very recently acquired LinkSys Etherfast 10/100 PCI card, based on
> the PNIC-II chipset.   When running an SMP-enabled kernel, things will run
> great for a while, and then I suddenly start getting calls from users
> complaining that the "network is slow".  Sure enough, I can do a telnet,
> or a domain logon to Samba from a Windows PC, and it appears as though the
> network connetion to the server is running at about 1/100th speed.  I.e.
> everything works, but VERY slowly.

I've gotten many reports of this type, with many different card types, all
runing the 2.2.10 kernel.  I've even experienced it with an instrumented
version of the eepro100 driver.  The driver appeared to be fine, it was the
kernel that was delaying the packets.

> If I take the network down on the server, and rmmod the tulip module, and
> then run "/etc/rc.d/init.d/network start" to bring networking backup,
> everything will be fine again for a while.  All in all, the slowdowns
> occur somewhat randomly, at least once or twice per day.

Doing this not only resets the network card, it reset the queue layer as
well.

> I *thought* I had seen mention of this, but looking through the mailing
> list archives on Tux, as well as the newsgroup archives on Dejanews
> doesn't turn up anything.

You likely saw it on other driver mailing lists, or on
linux-net/linux-kernel.

Try 2.2.11.

Donald Becker					  becker@cesdis.gsfc.nasa.gov
USRA-CESDIS, Center of Excellence in Space Data and Information Sciences.
Code 930.5, Goddard Space Flight Center,  Greenbelt, MD.  20771
301-286-0882	     http://cesdis.gsfc.nasa.gov/people/becker/whoiam.html