Bug 146841 - RHEL 4 U2: kernel panic when passing the 'nosmp' option to the x86_64 SMP kernel
Summary: RHEL 4 U2: kernel panic when passing the 'nosmp' option to the x86_64 SMP kernel
Alias: None
Product: Red Hat Enterprise Linux 4
Classification: Red Hat
Component: kernel   
(Show other bugs)
Version: 4.0
Hardware: x86_64
OS: Linux
Target Milestone: ---
: ---
Assignee: Jim Paradis
QA Contact: Brian Brock
Depends On:
Blocks: 170416
TreeView+ depends on / blocked
Reported: 2005-02-02 00:13 UTC by Amit Bhutani
Modified: 2013-08-06 01:11 UTC (History)
5 users (show)

Fixed In Version: RHEL4-U4
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2006-07-13 20:19:21 UTC
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)
serial console trace of bootup and panic (31.87 KB, text/plain)
2005-02-02 00:13 UTC, Amit Bhutani
no flags Details

Description Amit Bhutani 2005-02-02 00:13:07 UTC
Description of problem:
Passing the 'nosmp' option to a SMP enabled kernel causes a kernel 

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. Install RHEL 4 x86_64 official RC1 on a SC1420
2. When grub menu is displayed, pick the smp kernel and edit the 
command line options to add 'nosmp' at the end of the kernel line
3. Allow the system to boot
Actual results:
kernel panic

Expected results:
System boots normally

Additional info:
I have not tried this on with the x86 arch yet.

Comment 1 Amit Bhutani 2005-02-02 00:13:58 UTC
Created attachment 110536 [details]
serial console trace of bootup and panic

Comment 2 Susan Denham 2005-02-08 17:49:37 UTC
Per Dell weekly meeting (Dale), this is deferred to U2.

Comment 10 Andrew 2005-11-14 16:10:55 UTC
On dual Opteron hardware, booting the 32-bit Fedora Core 4 2.6.14-1.1637_FC4smp
Linux kernel with "nosmp" results in a similar problem.  After "OK, booting the
kernel" the system stops after repeating 7 times the message "IOAPIC[0]: Invalid
reference to IRQ 0".

Comment 13 Jim Paradis 2006-07-13 20:19:21 UTC
The kernel panic was fixed in U4 as a result of the fixes for Bug 174627 and Bug
176612.  That said, some systems still may not work with "nosmp" because it also
disables the IO APIC (See Comment 10).  The workaround for this is to use the
"noapic" flag along with "nosmp".  This is a known issue upstream as well.

Closing as CURRENTRELEASE for having fixed the panic.

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