dc TX underrun leads to delayed crash

[Peter C. Lai]

Patch seems to be working fine. I also seem to be getting better linkage and
transfer speeds too but that could just be my imagination *shrug*. Thanks.

On Wed, Jul 30, 2003 at 05:05:49PM -0500, Mike Silbersack wrote:
> 
> On Wed, 30 Jul 2003, Peter C. Lai wrote:
> 
> > I'm noticing on a moderately loaded system, that sometimes when the kernel
> > increases the TX threshold (/kernel: dc0: TX underrun -- increasing TX
> > threshold), a few minutes later, the system hardlocks requiring a reset.
> > This routinely happens when I'm streaming MP3s over the network and the box
> > suddenly hardlocks; after I go back to inspect the logs, the TX buffer underrun
> > is the only thing in the log before the start of the kernel reboot messages.
> > This is occuring on 4.8-STABLE as of July 7, 2003 on an AMD K6-2 500 with
> > 348 Mb RAM and VIA Apollo MVP3 chipset. When the lockups occur, the system
> > temperatures are below 40C, with little disk activity, moderate ram and cpu
> > usage; the NIC (linksys LNE-100TX A) is usually doing a steady 50K/s at this point.
> > --
> > Peter C. Lai
> 
> Rev 1.9.2.47 of if_dc.c (committed July 14th) should fix this problem for
> you.  MBUF_STRESS_TEST showed similar symptoms as mbuf chain lengths were
> increased, which is how I detected the problem.
> 
> Try grabbing the new if_dc.c:
> 
> http://www.freebsd.org/cgi/cvsweb.cgi/~checkout~/src/sys/pci/if_dc.c?rev=1.9.2.47&content-type=text/plain
> 
> And see how things go.
> 
> Mike "Silby" Silbersack

-- 
Peter C. Lai
University of Connecticut
Dept. of Molecular and Cell Biology
Yale University School of Medicine
SenseLab | Research Assistant
http://cowbert.2y.net/