Re: Problems with sky2 driver.

Re: Problems with sky2 driver.

[Daniel Drake]

Todd Showalter wrote:
>     I've been having trouble with the sky2 driver.  It appears to work
> most of the time, but it will quite often wedge during transfers.  The
> 2.6.17.* kernels actually seem worse than 2.6.16.19, but none of them
> work perfectly.
> 
>     What typically happens is that after working perfectly for a while,
> existing net connections hang, and subsequent net connections don't
> seem to start at all.  firefox gets stuck with a bunch of half-loaded
> pages, for instance, and I've watched an scp of a large file to a
> colleague's machine stall and remain stalled.

Please test with the very latest git snapshot. A critical fix was 
applied after 2.6.18-rc2 was released.

>     Once the machine is behaving this way, a reboot is the only way I
> have found of recovering it.
> 
>     We have two identical machines here that are both behaving this
> way, so I'm assuming it's not a hardware problem per se.  The machines
> are Intel Pentium D 940 (3GHz) processors.  They have ASUS P5LD2
> motherboards, with builtin Marvell PCIe 88E8053 gigabit ethernet
> controllers.
> 
>     I'm not running any binary modules; it's an untainted kernel.  I'm
> running a Gentoo system, but I'm using the vanilla-sources kernel (ie:
> a pure kernel.org release, not the Gentoo-specific patched version).
> 
>     What can I do to help solve this?

Re: Problems with sky2 driver.

[Stephen Hemminger]

On Mon, 24 Jul 2006 14:38:39 -0400
Todd Showalter <tshowalter@silverbirchstudios.com> wrote:

> On Mon, 24 Jul 2006 10:53:03 -0700, Stephen Hemminger
> <shemminger@osdl.org> wrote:
> 
> > There is a receive problem that shows up under load, that is fixed
> > in the latest version (2.6.18 git), the patch is queued for the stable
> > tree as well.
> 
>     I have hand-patched this in my 2.6.17.6 kernel.  It seems better
> (no hard wedge yet), but there are still definitely problems.
> 
>     The most obvious place is in firefox; for example, the front page
> of slashdot half-renders (all the borders, no stories) and then sits
> "loading" for eternity.  Ditto the online package database at
> gentoo.org.  I'm seeing similar behavior with other websites as well.
> It's consistant, too; I haven't been able to view the slashdot front
> page since booting a 2.6.17 kernel.


I suspect that probably isn't a sky2 driver problem.
Does it go away if you turn of TCP window scaling:
	sysctl -w net.ipv4.tcp_window_scaling=0

If so, you probably have a middlebox in your path that is not correctly
handling TCP window scaling. OpenBSD seems to be particularly bad.

> 
>     If I boot with the 2.6.16.9 kernel, I don't seem to get that
> problem until the network actually hangs.
> 
>                                                Todd.
> 
> --
>   Todd Showalter
>   Silverbirch Studios


-- 
Stephen Hemminger <shemminger@osdl.org>
"And in the Packet there writ down that doome"

Re: Problems with sky2 driver.

[Todd Showalter]

On Mon, 24 Jul 2006 11:45:33 -0700, Stephen Hemminger
<shemminger@osdl.org> wrote:

> I suspect that probably isn't a sky2 driver problem.
> Does it go away if you turn of TCP window scaling:
> 	sysctl -w net.ipv4.tcp_window_scaling=0
> 
> If so, you probably have a middlebox in your path that is not
> correctly handling TCP window scaling. OpenBSD seems to be
> particularly bad.

    This seems to be the case.  The combination of the patch and
shutting off tcp window scaling seems to have fixed the box.  Thanks!

    I'll ask around locally about network structure.

                                               Todd.

--
  Todd Showalter
  Silverbirch Studios