[PATCH] x86-64: Fix vgetcpu when CONFIG_HOTPLUG_CPU is disabled

The vgetcpu per CPU initialization previously relied on CPU hotplug
events for all CPUs to initialize the per CPU state. That only
worked only on kernels with CONFIG_HOTPLUG_CPU enabled.  On the
others some CPUs didn't get their state initialized properly
and vgetcpu wouldn't work.

Change the initialization sequence to instead run in a normal
initcall (which runs after the normal CPU bootup) and initialize
all running CPUs there. Later hotplug CPUs are still handled
with an hotplug notifier.

This actually simplifies the code somewhat.

Signed-off-by: Andi Kleen <ak@suse.de>

1 files changed, 1 insertions, 2 deletions

diff --git a/arch/x86_64/kernel/smp.c b/arch/x86_64/kernel/smp.c
index 4f67697f5036..9f74c883568c 100644
--- a/arch/x86_64/kernel/smp.c
+++ b/arch/x86_64/kernel/smp.c
@@ -376,9 +376,8 @@ int smp_call_function_single (int cpu, void (*func) (void *info), void *info,
         /* prevent preemption and reschedule on another processor */
         int me = get_cpu();
         if (cpu == me) {
-                WARN_ON(1);
                 put_cpu();
-                return -EBUSY;
+                return 0;
         }
         spin_lock_bh(&call_lock);
         __smp_call_function_single(cpu, func, info, nonatomic, wait);