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x86, apic: Limit apic dumping, introduce new show_lapic= setup option 

In case if a system has a large number of cpus printing apics
contents may consume a long time period.

We limit such an output by 1 apic by default. But to have an
ability to see all apics or some part of them we introduce
"show_lapic" setup option which allow us to limit/unlimit the
number of APICs being dumped.

Example: apic=debug show_lapic=5, or apic=debug show_lapic=all

Also move apic_verbosity checking upper that way so helper routines
do not need to inspect it at all.

Suggested-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: yinghai@kernel.org
Cc: macro@linux-mips.org
LKML-Reference: <20091013201022.926793122@openvz.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
hifive-unleashed-5.1
Cyrill Gorcunov 2009-10-14 00:07:05 +04:00 committed by Ingo Molnar
parent a933c61829
commit 2626eb2b2f
1 changed files with 32 additions and 15 deletions
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47
arch/x86/kernel/apic/io_apic.c
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@ -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(int base)
{
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(void *dummy)
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 +1815,19 @@ __apicdebuginit(void) print_local_APIC(void *dummy)
printk("\n");
}
__apicdebuginit(void) print_all_local_APICs(void)
__apicdebuginit(void) print_local_APICs(int maxcpu)
{
int cpu;
if (!maxcpu)
return;
preempt_disable();
for_each_online_cpu(cpu)
for_each_online_cpu(cpu) {
if (cpu >= maxcpu)
break;
smp_call_function_single(cpu, print_local_APIC, NULL, 1);
}
preempt_enable();
}
@ -1839,7 +1836,7 @@ __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 +1863,41 @@ __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 = -1;
if (strcmp(arg, "all") == 0) {
show_lapic = CONFIG_NR_CPUS;
} else {
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 */