[PATCH] Remove kstat.c CPU notifiers

[Rusty Russell]

Hi Andrew,

	Another cleanup extracted from the hotplug CPU patch.

Some well-meaning person put a notifier in for CPUs to update the
kstat structures in sched.c.  However, it does nothing, and even
with the full hotplug CPU patch, it still does nothing.

Simple counters very rarely need anything done when CPUs come up
or go down.  If you have per-cpu caches, or per-cpu threads, you
need to do something.  But very rarely for stats.

Name: Remove kstat CPU Notifier
Author: Rusty Russell
Status: Trivial

D: Some well-meaning person put a notifier in for CPUs to update the
D: kstat structures in sched.c.  However, it does nothing, and even
D: with the full hotplug CPU patch, it still does nothing.
D: 
D: Simple counters very rarely need anything done when CPUs come up
D: or go down.  If you have per-cpu caches, or per-cpu threads, you
D: need to do something.  But very rarely for stats.

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .31530-linux-2.6.1-bk6/kernel/sched.c .31530-linux-2.6.1-bk6.updated/kernel/sched.c
--- .31530-linux-2.6.1-bk6/kernel/sched.c	2004-01-21 10:02:33.000000000 +1100
+++ .31530-linux-2.6.1-bk6.updated/kernel/sched.c	2004-01-21 10:07:44.000000000 +1100
@@ -2848,45 +2999,11 @@ spinlock_t kernel_flag __cacheline_align
 EXPORT_SYMBOL(kernel_flag);
 #endif
 
-static void kstat_init_cpu(int cpu)
-{
-	/* Add any initialisation to kstat here */
-	/* Useful when cpu offlining logic is added.. */
-}
-
-static int __devinit kstat_cpu_notify(struct notifier_block *self,
-				      unsigned long action, void *hcpu)
-{
-	int cpu = (unsigned long)hcpu;
-	switch(action) {
-	case CPU_UP_PREPARE:
-		kstat_init_cpu(cpu);
-		break;
-	default:
-		break;
-	}
-	return NOTIFY_OK;
-}
-
-static struct notifier_block __devinitdata kstat_nb = {
-	.notifier_call	= kstat_cpu_notify,
-	.next		= NULL,
-};
-
-__init static void init_kstat(void)
-{
-	kstat_cpu_notify(&kstat_nb, (unsigned long)CPU_UP_PREPARE,
-			 (void *)(long)smp_processor_id());
-	register_cpu_notifier(&kstat_nb);
-}
-
 void __init sched_init(void)
 {
 	runqueue_t *rq;
 	int i, j, k;
 
-	/* Init the kstat counters */
-	init_kstat();
 	for (i = 0; i < NR_CPUS; i++) {
 		prio_array_t *array;
 

--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.
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