arch/x86/kernel/smpboot.c: Clarify when irq processing begins.

Secondary cpus start with local interrupts disabled.
start_secondary() first initializes the new cpu, then it enables the
local interrupts. (although interrupts are enabled within smp_callin()
as well).

Right now, the local interrupts are enabled as a side effect of calling
ipi_call_lock_irq().

The attached patch clarifies when local interrupts are enabled.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 5 insertions, 2 deletions

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 76b6f50978f7..b700c9a10644 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -334,14 +334,17 @@ static void __cpuinit start_secondary(void *unused)
          * does not change while we are assigning vectors to cpus.  Holding
          * this lock ensures we don't half assign or remove an irq from a cpu.
          */
-        ipi_call_lock_irq();
+        ipi_call_lock();
         lock_vector_lock();
         __setup_vector_irq(smp_processor_id());
         cpu_set(smp_processor_id(), cpu_online_map);
         unlock_vector_lock();
-        ipi_call_unlock_irq();
+        ipi_call_unlock();
         per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
 
+        /* enable local interrupts */
+        local_irq_enable();
+
         setup_secondary_clock();
 
         wmb();