Red Hat Bugzilla – Bug 146841
RHEL 4 U2: kernel panic when passing the 'nosmp' option to the x86_64 SMP kernel
Last modified: 2013-08-05 21:11:48 EDT
Description of problem:
Passing the 'nosmp' option to a SMP enabled kernel causes a kernel
Version-Release number of selected component (if applicable):
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
System boots normally
I have not tried this on with the x86 arch yet.
Created attachment 110536 [details]
serial console trace of bootup and panic
Per Dell weekly meeting (Dale), this is deferred to U2.
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: Invalid
reference to IRQ 0".
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.