Bug 3247

Summary: Hard stop under heavy IDE/Network traffic
Product: [Retired] Red Hat Linux Reporter: Martin C. Messer <mmesser>
Component: kernelAssignee: David Lawrence <dkl>
Severity: medium Docs Contact:
Priority: medium    
Version: 6.0   
Target Milestone: ---   
Target Release: ---   
Hardware: i386   
OS: Linux   
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 1999-06-04 21:06:54 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description Martin C. Messer 1999-06-03 18:08:17 UTC
Customer explains:

With heavy disk usage and net activity my machine crashes.
I'm running 6.0 on a 686, 10 Gb EIDE, I forget the ethernet
card (the machine is not local, can't check at the moment)
but the driver is the epic100.  This is definitely a serious
6.0 problem as 5.1 ran on the same hardware for around 8
months with no trouble whatsoever under extremely heavy
usage conditions.

He can reproduce this by running 'hdparm -t /dev/hda' while
ping flooding the machine.

I was not able to reproduce it. It seems similar to bug
#2938, and customer tried steeping down to 386 optimization,
though he did not remove Watchdog or APM. Same results.

Comment 1 David Lawrence 1999-06-04 21:06:59 UTC
I was unable to get this to fail on a test lab machine containing a
Cyrix MII 300. I ping flooded the machine while running the hdparm -t
/dev/hda command. It got noticable slower but never locked up.

------- Additional Comments From   06/12/99 01:43 -------
Some info got left off of my original report below.  First, another
user saw exactly the same behavior:
I don't get a reboot, the machine just locks up.

Second, doing a hdparm -d 1/dev/hda (i.e. enabling DMA)
"solves" the problem.

Third, ifconfig shows that packets are being dropped prior
to the failure.  If I am ftp'ing a large file, the machine
locks, but the halt can be avoided if I continually do network
restarts during the transfer.

Comment 2 Alan Cox 1999-06-12 13:24:59 UTC
This is a real bug in the EPIC100 driver. It requires that interrupts
are deferred for a long time while the card receives only small
frames. The fix is in 2.2.7 or so and higher, I can provide it if
need be.