[PATCH] x86: add show_lapic=

From: Yinghai Lu
Date: Sun Sep 27 2009 - 03:02:38 EST



so could use that together with apci=debug to print less cpu apic.

otherwise for system have more cpus will take a while

also move apic_verbosity check to print_all_ICs

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>

---
arch/x86/kernel/apic/io_apic.c | 42 ++++++++++++++++++++++++++---------------
1 file changed, 27 insertions(+), 15 deletions(-)

Index: linux-2.6/arch/x86/kernel/apic/io_apic.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/apic/io_apic.c
+++ linux-2.6/arch/x86/kernel/apic/io_apic.c
@@ -1599,9 +1599,6 @@ __apicdebuginit(void) print_IO_APIC(void
struct irq_desc *desc;
unsigned int irq;

- if (apic_verbosity == APIC_QUIET)
- return;
-
printk(KERN_DEBUG "number of MP IRQ sources: %d.\n", mp_irq_entries);
for (i = 0; i < nr_ioapics; i++)
printk(KERN_DEBUG "number of IO-APIC #%d registers: %d.\n",
@@ -1708,9 +1705,6 @@ __apicdebuginit(void) print_APIC_field(i
{
int i;

- if (apic_verbosity == APIC_QUIET)
- return;
-
printk(KERN_DEBUG);

for (i = 0; i < 8; i++)
@@ -1724,9 +1718,6 @@ __apicdebuginit(void) print_local_APIC(v
unsigned int i, v, ver, maxlvt;
u64 icr;

- if (apic_verbosity == APIC_QUIET)
- return;
-
printk(KERN_DEBUG "printing local APIC contents on CPU#%d/%d:\n",
smp_processor_id(), hard_smp_processor_id());
v = apic_read(APIC_ID);
@@ -1824,13 +1815,17 @@ __apicdebuginit(void) print_local_APIC(v
printk("\n");
}

-__apicdebuginit(void) print_all_local_APICs(void)
+__apicdebuginit(void) print_local_APICs(int num)
{
int cpu;

preempt_disable();
- for_each_online_cpu(cpu)
+ for_each_online_cpu(cpu) {
+ if (cpu >= num)
+ break;
+
smp_call_function_single(cpu, print_local_APIC, NULL, 1);
+ }
preempt_enable();
}

@@ -1839,7 +1834,7 @@ __apicdebuginit(void) print_PIC(void)
unsigned int v;
unsigned long flags;

- if (apic_verbosity == APIC_QUIET || !nr_legacy_irqs)
+ if (!nr_legacy_irqs)
return;

printk(KERN_DEBUG "\nprinting PIC contents\n");
@@ -1866,21 +1861,38 @@ __apicdebuginit(void) print_PIC(void)
printk(KERN_DEBUG "... PIC ELCR: %04x\n", v);
}

-__apicdebuginit(int) print_all_ICs(void)
+static int __initdata show_lapic = 1;
+static __init int setup_show_lapic(char *arg)
+{
+ int num;
+
+ get_option(&arg, &num);
+
+ if (num >= 0)
+ show_lapic = num;
+
+ return 1;
+}
+__setup("show_lapic=", setup_show_lapic);
+
+__apicdebuginit(int) print_ICs(void)
{
+ if (apic_verbosity == APIC_QUIET)
+ return 0;
+
print_PIC();

/* don't print out if apic is not there */
if (!cpu_has_apic && !apic_from_smp_config())
return 0;

- print_all_local_APICs();
+ print_local_APICs(show_lapic);
print_IO_APIC();

return 0;
}

-fs_initcall(print_all_ICs);
+fs_initcall(print_ICs);


/* Where if anywhere is the i8259 connect in external int mode */
--
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