Commit e545a614 authored by Manfred Spraul's avatar Manfred Spraul Committed by Ingo Molnar
Browse files

kernel/cpu.c: create a CPU_STARTING cpu_chain notifier 



Right now, there is no notifier that is called on a new cpu, before the new
cpu begins processing interrupts/softirqs.
Various kernel function would need that notification, e.g. kvm works around
by calling smp_call_function_single(), rcu polls cpu_online_map.

The patch adds a CPU_STARTING notification. It also adds a helper function
that sends the message to all cpu_chain handlers.

Tested on x86-64.
All other archs are untested. Especially on sparc, I'm not sure if I got
it right.

Signed-off-by: default avatarManfred Spraul <manfred@colorfullife.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 7686ad56

arch/alpha/kernel/smp.c

+3 −0
Original line number Diff line number Diff line
@@ -149,6 +149,9 @@ smp_callin(void) 
	atomic_inc(&init_mm.mm_count);

	current->active_mm = &init_mm;



	/* inform the notifiers about the new cpu */

	notify_cpu_starting(cpuid);



	/* Must have completely accurate bogos.  */

	local_irq_enable();

arch/arm/kernel/smp.c

+1 −0
Original line number Diff line number Diff line
@@ -277,6 +277,7 @@ asmlinkage void __cpuinit secondary_start_kernel(void) 
	/*

	 * Enable local interrupts.

	 */

	notify_cpu_starting(cpu);

	local_irq_enable();

	local_fiq_enable();

arch/cris/arch-v32/kernel/smp.c

+1 −0
Original line number Diff line number Diff line
@@ -178,6 +178,7 @@ void __init smp_callin(void) 
	unmask_irq(IPI_INTR_VECT);

	unmask_irq(TIMER0_INTR_VECT);

	preempt_disable();

	notify_cpu_starting(cpu);

	local_irq_enable();



	cpu_set(cpu, cpu_online_map);

arch/ia64/kernel/smpboot.c

+1 −0
Original line number Diff line number Diff line
@@ -401,6 +401,7 @@ smp_callin (void) 
	spin_lock(&vector_lock);

	/* Setup the per cpu irq handling data structures */

	__setup_vector_irq(cpuid);

	notify_cpu_starting(cpuid);

	cpu_set(cpuid, cpu_online_map);

	per_cpu(cpu_state, cpuid) = CPU_ONLINE;

	spin_unlock(&vector_lock);

arch/m32r/kernel/smpboot.c

+2 −0
Original line number Diff line number Diff line
@@ -498,6 +498,8 @@ static void __init smp_online(void) 
{

	int cpu_id = smp_processor_id();



	notify_cpu_starting(cpu_id);



	local_irq_enable();



	/* Get our bogomips. */

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