Bug 78559

Summary: Can't boot SMP kernel on UP machine
Product: [Retired] Red Hat Linux Reporter: paulm
Component: kernelAssignee: Arjan van de Ven <arjanv>
Status: CLOSED CURRENTRELEASE QA Contact: Brian Brock <bbrock>
Severity: medium Docs Contact:
Priority: medium    
Version: 7.3CC: akopps, betka, per, seth.mos
Target Milestone: ---   
Target Release: ---   
Hardware: i686   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2004-09-30 15:40:14 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Attachments:
Description Flags
2.4.19-smp succesful boot log. none

Description paulm 2002-11-25 20:55:58 UTC 
From Bugzilla Helper:
User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; .NET CLR 
1.0.3705)

Description of problem:


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


How reproducible:
Always

Steps to Reproduce:
1. Install stock kernel-smp-2.4.18-18.7.x.i686
2. on IBM netfinity 5100 Uniprocessor (scsi)
3. Reboot....
	

Actual Results:  The server hung during the boot sequence

Expected Results:  Should be able to boot an SMP kernel on a Uni Processor 
server. 

Additional info:

I installed the non-smp of the same kernel, and that worked fine, I also went 
back to a 2.4.18-10 smp kernel, and booted fine. I have always been able to 
run SMP kernels on UP machines (it is a requirement to be able to run on smp 
servers if we have a cpu fail)  I also tested a few other varieties of i686 
servers, and they cannot boot this version of the smp kernel either.
Comment 1 Seth Mos 2002-11-26 09:36:51 UTC 
Me too, the boot hangs after the 2048 pty line.

PowerEdge 1300 Single PIII 450
Intel 440BX mainboard (smap capable)
256MB ECC SDRAM
40GB IDE bootdrive on onboard IDE controller.
Latest BIOS
2.4.19-smp succesful bootlog attached.
Comment 2 Seth Mos 2002-11-26 09:37:52 UTC 
Created attachment 86484 [details]
2.4.19-smp succesful boot log.
Comment 3 paulm 2002-11-27 20:35:30 UTC 
More helpful info- boot fails at this line:
Real Time Clock Driver
Comment 4 Per Hedeland 2003-03-21 23:54:50 UTC 
This sounds very similar to the bug I'm seeing with kernel 2.4.18-26.7.x
- the SMP kernel hangs at boot on a number of UP systems where 2.4.18-26.7.x
UP works fine, as does 2.4.18-10 SMP. I believe the common thing with the
systems that fail is that they have an "IO-APIC", e.g. systems with SMP
support but only one CPU installed, but also others.

E.g. here is the final output on a Dell-1550 with one CPU
installed:

  ...
  PCI->APIC IRQ transform: (B2,I5,P1) -> 28
  PCI->APIC IRQ transform: (B2,I6,P0) -> 29
  Linux NET4.0 for Linux 2.4
  Based upon Swansea University Computer Society NET3.039
  Initializing RT netlink socket
  Starting kswapd
  pt

The modification in the diff below seems to fix or at least work
around the problem, but I'm unsure whether it is the "proper"
one - any comments appreciated.

Thanks

--Per Hedeland

--- arch/i386/kernel/io_apic.c.ORIG	  5 Mar 2003 11:24:51 -0000
+++ arch/i386/kernel/io_apic.c  19 Mar 2003 23:04:28 -0000
@@ -249,6 +249,8 @@
	  irq_balance_t *entry = irq_balance + irq;
	  unsigned long now = jiffies;
 
+	  if (smp_num_cpus == 1)
+		  return;
	  if (unlikely(entry->timestamp != now)) {
		  unsigned long allowed_mask;
		  int random_number;
Comment 5 Bugzilla owner 2004-09-30 15:40:14 UTC 
Thanks for the bug report. However, Red Hat no longer maintains this version of
the product. Please upgrade to the latest version and open a new bug if the problem
persists.

The Fedora Legacy project (http://fedoralegacy.org/) maintains some older releases, 
and if you believe this bug is interesting to them, please report the problem in
the bug tracker at: http://bugzilla.fedora.us/