Re: 2.6.8-rc3-mm2

[William Lee Irwin III <wli@holomorphy.com>]

On Mon, Aug 09, 2004 at 12:17:50PM -0700, Jesse Barnes wrote:
>>> If I apply everything up to and including schedstat-v10.patch, it
>>> boots fine. So it might be sched-init_idle-fork_by_hand-consolidation.patch
>>> or something nearby...  Just reverting the sched-single-array.patch
>>> wasn't enough.

On Mon, Aug 09, 2004 at 12:53:23PM -0700, William Lee Irwin III wrote:
>> I can reproduce here (ia64/Altix). Fixing.

On Mon, Aug 09, 2004 at 01:43:57PM -0700, William Lee Irwin III wrote:
> It comes up with the following applied. Now distilling into a bugfix.

The following does *NOT* come up. The difference appears to be the delay
from the printk()'s.


-- wli

--- mm2-2.6.8-rc3/arch/ia64/kernel/smpboot.c.orig	2004-08-10 05:24:20.000000000 -0700
+++ mm2-2.6.8-rc3/arch/ia64/kernel/smpboot.c	2004-08-10 06:50:21.774710311 -0700
@@ -356,44 +356,17 @@
 	return cpu_idle();
 }
 
-struct create_idle {
-	struct task_struct *idle;
-	struct completion done;
-	int cpu;
-};
-
-void
-do_fork_idle(void *_c_idle)
-{
-	struct create_idle *c_idle = _c_idle;
-
-	c_idle->idle = fork_idle(c_idle->cpu);
-	complete(&c_idle->done);
-}
-
 static int __devinit
 do_boot_cpu (int sapicid, int cpu)
 {
 	int timeout;
-	struct create_idle c_idle = {
-		.cpu	= cpu,
-		.done	= COMPLETION_INITIALIZER(c_idle.done),
-	};
-	DECLARE_WORK(work, do_fork_idle, &c_idle);
 	/*
 	 * We can't use kernel_thread since we must avoid to reschedule the child.
 	 */
-	if (!keventd_up() || current_is_keventd())
-		work.func(work.data);
-	else {
-		schedule_work(&work);
-		wait_for_completion(&c_idle.done);
-	}
-
-	if (IS_ERR(c_idle.idle))
+	task_for_booting_cpu = fork_idle(cpu);
+	if (IS_ERR(task_for_booting_cpu))
 		panic("failed fork for CPU %d", cpu);
-	task_for_booting_cpu = c_idle.idle;
-
+	mb();
 	Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid);
 
 	platform_send_ipi(cpu, ap_wakeup_vector, IA64_IPI_DM_INT, 0);
--- mm2-2.6.8-rc3/kernel/fork.c.orig	2004-08-10 06:02:27.000000000 -0700
+++ mm2-2.6.8-rc3/kernel/fork.c	2004-08-10 06:03:11.000000000 -0700
@@ -1190,7 +1190,7 @@
 	goto fork_out;
 }
 
-task_t * __init fork_idle(int cpu)
+task_t *fork_idle(int cpu)
 {
 	task_t *task;
 	struct pt_regs regs;