Hi,For my rcu implementation, I try to figure out how the boot process for secondary cpus works.
arch/ia64/kernel/smpboot.c contains the following code:
static void __cpuinit smp_callin (void) { [snip] per_cpu(cpu_state, cpuid) = CPU_ONLINE; spin_unlock(&vector_lock); ipi_call_unlock_irq(); <<<<< <<<<< ipi_call_unlock_irq() does local_irq_enable() <<<<< smp_setup_percpu_timer(); ia64_mca_cmc_vector_setup(); /* Setup vector on AP */ #ifdef CONFIG_PERFMON pfm_init_percpu(); #endif local_irq_enable(); <<<<< <<<<< Another local_irq_enable(). <<<<<
Which of these two local_irq_enable()'s is the right one?And: IMHO it's unclean to abuse ipi_call_unlock_irq() to enable the local interrupts.
What about the attached patch? Untested due to lack of test hardware. -- Manfred
diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c index 03f1a99..f4868d2 100644 --- a/arch/ia64/kernel/smpboot.c +++ b/arch/ia64/kernel/smpboot.c @@ -396,14 +396,17 @@ smp_callin (void) fix_b0_for_bsp(); - ipi_call_lock_irq(); + ipi_call_lock(); spin_lock(&vector_lock); /* Setup the per cpu irq handling data structures */ __setup_vector_irq(cpuid); cpu_set(cpuid, cpu_online_map); per_cpu(cpu_state, cpuid) = CPU_ONLINE; spin_unlock(&vector_lock); - ipi_call_unlock_irq(); + ipi_call_unlock(); + + /* begin processing interrupts */ + local_irq_enable(); smp_setup_percpu_timer(); @@ -413,8 +416,6 @@ smp_callin (void) pfm_init_percpu(); #endif - local_irq_enable(); - if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) { /* * Synchronize the ITC with the BP. Need to do this after irqs are
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