Backtrae before smp_init.

[Keith Owens]

On Wed, 26 Mar 2003 14:00:10 +0800, 
"Dong, Edie" <edie.dong at intel.com> wrote:
>VGhhdCBpcyBzdHJhbmdlciwgSSBnb3QgdGhlIHByb2dyYW0gdG8gIlN0YWNrIGlzIG5vdCBpbiB0

Ugh, please use plain text.

>That is stranger, I got the program to "Stack is not in task_struct, backtrace not available",
>(in kdba_bt_stack), I checked the macro task_has_cpu(p) is false beacuse the initial task is
>not switched yet, and the memory in &p->thread are all 0. (md &p->thread).
>Any hints?

You should have included that information in your original mail,
instead of making us guess what error you were getting.  This is a
kernel bug where it incorrectly sets scheduling fields on the idle
tasks.

diff -ur 2.4.20-pristine/arch/i386/kernel/smpboot.c 2.4.20-sched/arch/i386/kernel/smpboot.c
--- 2.4.20-pristine/arch/i386/kernel/smpboot.c	Fri Nov 29 11:38:59 2002
+++ 2.4.20-sched/arch/i386/kernel/smpboot.c	Wed Mar 26 16:22:49 2003
@@ -803,8 +803,7 @@
 	if (!idle)
 		panic("No idle process for CPU %d", cpu);
 
-	idle->processor = cpu;
-	idle->cpus_runnable = 1 << cpu; /* we schedule the first task manually */
+	task_set_cpu_only(idle, cpu);	/* we schedule the first task manually */
 
 	map_cpu_to_boot_apicid(cpu, apicid);
 
diff -ur 2.4.20-pristine/include/linux/sched.h 2.4.20-sched/include/linux/sched.h
--- 2.4.20-pristine/include/linux/sched.h	Mon Mar 17 15:35:32 2003
+++ 2.4.20-sched/include/linux/sched.h	Wed Mar 26 16:14:40 2003
@@ -568,6 +568,12 @@
 	tsk->cpus_runnable = 1UL << cpu;
 }
 
+static inline void task_set_cpu_only(struct task_struct *tsk, unsigned int cpu)
+{
+	task_set_cpu(tsk, cpu);
+	tsk->cpus_allowed = 1UL << cpu;
+}
+
 static inline void task_release_cpu(struct task_struct *tsk)
 {
 	tsk->cpus_runnable = ~0UL;
diff -ur 2.4.20-pristine/init/main.c 2.4.20-sched/init/main.c
--- 2.4.20-pristine/init/main.c	Wed May 29 14:00:22 2002
+++ 2.4.20-sched/init/main.c	Wed Mar 26 16:30:23 2003
@@ -354,6 +354,7 @@
  * enable them
  */
 	lock_kernel();
+	task_set_cpu_only(current, 0);
 	printk(linux_banner);
 	setup_arch(&command_line);
 	printk("Kernel command line: %s\n", saved_command_line);
diff -ur 2.4.20-pristine/kernel/sched.c 2.4.20-sched/kernel/sched.c
--- 2.4.20-pristine/kernel/sched.c	Fri Aug 30 13:51:40 2002
+++ 2.4.20-sched/kernel/sched.c	Wed Mar 26 16:27:35 2003
@@ -525,6 +525,7 @@
 		goto out_unlock;
 	}
 #else
+	task_release_cpu(prev);
 	prev->policy &= ~SCHED_YIELD;
 #endif /* CONFIG_SMP */
 }