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

From: Manfred Spraul
Date: Sun Sep 07 2008 - 05:53:01 EST


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-of-By: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx>
---
arch/x86/kernel/smpboot.c | 7 +++++--
1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 3325127..9bfa037 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -327,14 +327,17 @@ static void __cpuinit start_secondary(void *unused)
* lock helps us to not include this cpu in a currently in progress
* smp_call_function().
*/
- ipi_call_lock_irq();
+ ipi_call_lock();
#ifdef CONFIG_X86_IO_APIC
setup_vector_irq(smp_processor_id());
#endif
cpu_set(smp_processor_id(), cpu_online_map);
- 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();
--
1.5.5.1

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