Bug 3550

Summary:	CPU at 100% when burning audio cds
Product:	IO/Storage	Reporter:	Pedro de Oliveira (falsovsky)
Component:	IDE	Assignee:	Diego Calleja (diegocg)
Status:	CLOSED CODE_FIX
Severity:	high	CC:	cozmic.fi, diegocg, t8m
Priority:	P2
Hardware:	i386
OS:	Linux
Kernel Version:	2.6.8, and 2.6.9rc's	Subsystem:
Regression:	---	Bisected commit-id:

Description Pedro de Oliveira 2004-10-11 06:10:13 UTC

Distribution: Gentoo, kernel 2.6.8
Hardware Environment: BENQ cd recorder
Software Environment: cdrecord
Problem Description:
When i burn a audio cd with cdrecord my computer goes to a crawl using 100% of
cpu and burning the cd takes like 15minutes on a burner that does 48X burning.
Im using IDE burning like dev=ATA:1,0,0.
This only happens with cdrecord, and not with cdrdao.
Im having this problem since this kernel, with older kernels i didnt had this.
I tried some 2.6.9-rc's and the problem is still there.

Steps to reproduce:
Burn an audio cd with cdrecord

Comment 1 Tom Mraz 2004-11-09 10:45:27 UTC

Maybe this?
http://kerneltrap.org/node/view/3659

Comment 2 Ruediger 2005-01-04 13:15:56 UTC

I suppose that this bug is not related to the memory leak of kernel 2.6.8.

There are several posts of users having problems burning audio CDs at high speed:
http://bugs.kde.org/show_bug.cgi?id=95509
http://sourceforge.net/mailarchive/forum.php?thread_id=6260166&forum_id=1927
http://bugs.gentoo.org/show_bug.cgi?id=63040

What I would say after collecting the information from these posts:
When burning audio CDs in TAO or DAO/SAO mode, the kernel uses much CPU time in
hardware interrupts (~50% on an AMD 2200+ burning at 10x speed).
The problem exists in kernels 2.6.7 and 2.6.9.
If Jeff (Gentoo bug) is right and has the same problem, it does not appear in 2.6.5.
Burning an audio CD in raw mode instead of DAO does not cause the problem.

I can reproduce the problem myself with Gentoo's 2.6.9-r13 and cdrecord 2.01.

Comment 3 Ruediger 2005-01-06 04:42:32 UTC

Just tested with 2.6.10-gentoo-r2 -> no change.

Comment 4 Christian Borntraeger 2005-01-26 14:16:32 UTC

I can confirm this problem with debian testing from Jan 26th,2005 and the 
debian 2.6.8 kernel. 
Burning audio cds results in  about 50% cpu consumption for hardware interrupts 
(according to top) on an 8x burner. Burning the audio CD in RAW mode works 
fine.

Comment 5 Diego Calleja 2006-08-04 05:43:39 UTC

Can you reproduce it with modern kernels?

Comment 6 Ruediger 2006-08-04 08:35:06 UTC

No. Seems to be solved already.
I just retested with 2.6.17, but I remember that I could not reproduce the
problem with an earlier version.

Comment 7 Diego Calleja 2006-08-04 12:57:48 UTC

ok, so I'm closing it