Bug 20892

Summary:	PROBLEM: kernel 2.6.35.7 crashes under I/O load
Product:	IO/Storage	Reporter:	Maciej Rutecki (maciej.rutecki)
Component:	Other	Assignee:	io_other
Status:	RESOLVED OBSOLETE
Severity:	normal	CC:	alan, evogt, maciej.rutecki, rjw, seanmbusby
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	2.6.35.7	Subsystem:
Regression:	Yes	Bisected commit-id:
Bug Depends on:
Bug Blocks:	16055

Description Maciej Rutecki 2010-10-21 18:21:26 UTC

Subject    : PROBLEM: kernel 2.6.35.7 crashes under I/O load
Submitter  : Etienne Vogt <evogt@free.fr>
Date       : 2010-10-20 21:20
Message-ID : alpine.DEB.1.10.1010202300540.3989@coniglio.vogt-bodving.test
References : http://marc.info/?l=linux-kernel&m=128761179615272&w=2

This entry is being used for tracking a regression from 2.6.34. Please don't
close it until the problem is fixed in the mainline.

Comment 1 Sean Busby 2010-10-23 14:21:06 UTC

I've seen this since 2.6.31.*, mostly when doing multiple simultaneous video encodes which produced heavy I/O load.  Finally found this solution: http://ubuntuforums.org/showthread.php?t=1363283

Setting libata.force=noncq kernel option at boot and turning off the HDD's write caching with hdparm seems to have solved it.

Comment 2 Etienne Vogt 2010-10-23 16:25:02 UTC

The problem reported by Sean Busby is probably different : I'm using the legacy IDE stack, not libata and it never crashed for me under 2.6.34.
I upgraded to 2.6.36 yesterday and for the moment, no crashes. I reprocessed the mpeg file that crashed under 2.6.35.7 and it worked fine under 2.6.36.
It's perhaps a bit early to say the problem is no longer present under 2.6.36, but at least it looks better.