Bug 3247

Summary:	Hard stop under heavy IDE/Network traffic
Product:	[Retired] Red Hat Linux	Reporter:	Martin C. Messer <mmesser>
Component:	kernel	Assignee:	David Lawrence <dkl>
Status:	CLOSED WORKSFORME	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	6.0
Target Milestone:	---
Target Release:	---
Hardware:	i386
OS:	Linux
Whiteboard:
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:
http://x28.deja.com/getdoc.xp?AN=484168039.1&CONTEXT=928218503.648347748&hitnum=20
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.