Re: 2.6.7-mm6

[Ingo Molnar <mingo@elte.hu>]

* David S. Miller <davem@redhat.com> wrote:

> On Tue, 6 Jul 2004 16:36:18 -0700
> William Lee Irwin III <wli@holomorphy.com> wrote:
> 
> > I have it isolated down to the sched-clean-init-idle.patch and
> > sched-clean-fork.patch. sched-clean-init-idle.patch fails to build without
> > the second of those two applied, so I didn't do any work to narrow it down
> > further.
> 
> One thing to note is that we don't currently call the
> wake_up_forked_process() thing in our SMP idle bootup
> dispatcher in arch/sparc64/kernel/smp.c

the patch below should solve this. Is it safe on sparc to do a
fork_by_hand() like this?

	Ingo

--- linux/arch/sparc64/kernel/smp.c.orig	
+++ linux/arch/sparc64/kernel/smp.c	
@@ -293,6 +293,16 @@ extern unsigned long sparc64_cpu_startup
  */
 static struct thread_info *cpu_new_thread = NULL;
 
+static struct task_struct * __init fork_by_hand(void)
+{
+	struct pt_regs regs;
+	/*
+	 * don't care about the regs settings since
+	 * we'll never reschedule the forked task.
+	 */
+	return copy_process(CLONE_VM|CLONE_IDLETASK, 0, &regs, 0, NULL, NULL);
+}
+
 static int __devinit smp_boot_one_cpu(unsigned int cpu)
 {
 	unsigned long entry =
@@ -302,9 +312,7 @@ static int __devinit smp_boot_one_cpu(un
 	struct task_struct *p;
 	int timeout, ret, cpu_node;
 
-	kernel_thread(NULL, NULL, CLONE_IDLETASK);
-
-	p = prev_task(&init_task);
+	p = fork_by_hand();
 
 	init_idle(p, cpu);