Re: 2.6.25-mm1: not looking good

[Ingo Molnar <mingo@elte.hu>]

* Ingo Molnar <mingo@elte.hu> wrote:

> Subject: x86: disable preemption in native_smp_prepare_cpus

that should be the patch below.

	Ingo

------------>
Subject: x86: disable preemption in native_smp_prepare_cpus
From: Ingo Molnar <mingo@elte.hu>
Date: Fri Apr 18 11:07:10 CEST 2008

Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/smpboot.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Index: linux-x86.q/arch/x86/kernel/smpboot.c
===================================================================
--- linux-x86.q.orig/arch/x86/kernel/smpboot.c
+++ linux-x86.q/arch/x86/kernel/smpboot.c
@@ -1181,6 +1181,7 @@ static void __init smp_cpu_index_default
  */
 void __init native_smp_prepare_cpus(unsigned int max_cpus)
 {
+	preempt_disable();
 	nmi_watchdog_default();
 	smp_cpu_index_default();
 	current_cpu_data = boot_cpu_data;
@@ -1197,7 +1198,7 @@ void __init native_smp_prepare_cpus(unsi
 	if (smp_sanity_check(max_cpus) < 0) {
 		printk(KERN_INFO "SMP disabled\n");
 		disable_smp();
-		return;
+		goto out;
 	}
 
 	preempt_disable();
@@ -1237,6 +1238,8 @@ void __init native_smp_prepare_cpus(unsi
 	printk(KERN_INFO "CPU%d: ", 0);
 	print_cpu_info(&cpu_data(0));
 	setup_boot_clock();
+out:
+	preempt_enable();
 }
 /*
  * Early setup to make printk work.