From c376d45432d935e6f1e0ff2d6be3734bcd3ba455 Mon Sep 17 00:00:00 2001
From: Cyrill Gorcunov <gorcunov@gmail.com>
Date: Tue, 24 Jun 2008 22:52:05 +0200
Subject: [PATCH] x86: nmi_watchdog - use NMI_NONE by default
There is no need to keep NMI_DISABLED definition and use it
for nmi_watchdog by default. Here is the point why:
- IO-APIC and APIC chips are programmed for nmi_watchdog support at very
early stage of kernel booting and not having nmi_watchdog specified as
boot option lead only to nmi_watchdog becomes to NMI_NONE anyway
- enable nmi_watchdog thru /proc/sys/kernel/nmi if it was not specified at
boot is not possible too (even having this sysfs entry)
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: macro@linux-mips.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/kernel/apic_64.c | 1 -
arch/x86/kernel/io_apic_64.c | 2 --
arch/x86/kernel/nmi.c | 26 +++-----------------------
arch/x86/kernel/smpboot.c | 1 -
include/asm-x86/nmi.h | 3 ---
5 files changed, 3 insertions(+), 30 deletions(-)
diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c
index 8c751f731bca9..1e3d32e27c14c 100644
--- a/arch/x86/kernel/apic_64.c
+++ b/arch/x86/kernel/apic_64.c
@@ -826,7 +826,6 @@ static void __cpuinit lapic_setup_esr(void)
void __cpuinit end_local_APIC_setup(void)
{
lapic_setup_esr();
- nmi_watchdog_default();
setup_apic_nmi_watchdog(NULL);
apic_pm_activate();
}
diff --git a/arch/x86/kernel/io_apic_64.c b/arch/x86/kernel/io_apic_64.c
index 08c48750888a7..2b4c40bc12c91 100644
--- a/arch/x86/kernel/io_apic_64.c
+++ b/arch/x86/kernel/io_apic_64.c
@@ -1729,7 +1729,6 @@ static inline void __init check_timer(void)
}
unmask_IO_APIC_irq(0);
if (!no_timer_check && timer_irq_works()) {
- nmi_watchdog_default();
if (nmi_watchdog == NMI_IO_APIC) {
setup_nmi();
enable_8259A_irq(0);
@@ -1758,7 +1757,6 @@ static inline void __init check_timer(void)
if (timer_irq_works()) {
apic_printk(APIC_VERBOSE," works.\n");
timer_through_8259 = 1;
- nmi_watchdog_default();
if (nmi_watchdog == NMI_IO_APIC) {
disable_8259A_irq(0);
setup_nmi();
diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 427c511e7adc0..32acda25e3cb6 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -52,7 +52,7 @@ static cpumask_t backtrace_mask = CPU_MASK_NONE;
atomic_t nmi_active = ATOMIC_INIT(0); /* oprofile uses this */
EXPORT_SYMBOL(nmi_active);
-unsigned int nmi_watchdog = NMI_DEFAULT;
+unsigned int nmi_watchdog = NMI_NONE;
EXPORT_SYMBOL(nmi_watchdog);
static int panic_on_timeout;
@@ -92,14 +92,6 @@ static inline unsigned int get_timer_irqs(int cpu)
#endif
}
-/* Run after command line and cpu_init init, but before all other checks */
-void nmi_watchdog_default(void)
-{
- if (nmi_watchdog != NMI_DEFAULT)
- return;
- nmi_watchdog = NMI_NONE;
-}
-
#ifdef CONFIG_SMP
/*
* The performance counters used by NMI_LOCAL_APIC don't trigger when
@@ -127,7 +119,7 @@ int __init check_nmi_watchdog(void)
unsigned int *prev_nmi_count;
int cpu;
- if (nmi_watchdog == NMI_NONE || nmi_watchdog == NMI_DISABLED)
+ if (nmi_watchdog == NMI_NONE)
return 0;
if (!atomic_read(&nmi_active))
@@ -482,24 +474,12 @@ int proc_nmi_enabled(struct ctl_table *table, int write, struct file *file,
if (!!old_state == !!nmi_watchdog_enabled)
return 0;
- if (atomic_read(&nmi_active) < 0 || nmi_watchdog == NMI_DISABLED) {
+ if (atomic_read(&nmi_active) < 0 || nmi_watchdog == NMI_NONE) {
printk(KERN_WARNING
"NMI watchdog is permanently disabled\n");
return -EIO;
}
- /* if nmi_watchdog is not set yet, then set it */
- nmi_watchdog_default();
-
-#ifdef CONFIG_X86_32
- if (nmi_watchdog == NMI_NONE) {
- if (lapic_watchdog_ok())
- nmi_watchdog = NMI_LOCAL_APIC;
- else
- nmi_watchdog = NMI_IO_APIC;
- }
-#endif
-
if (nmi_watchdog == NMI_LOCAL_APIC) {
if (nmi_watchdog_enabled)
enable_lapic_nmi_watchdog();
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 3b48d1f4c7c3c..3b19441d78b85 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1139,7 +1139,6 @@ static void __init smp_cpu_index_default(void)
void __init native_smp_prepare_cpus(unsigned int max_cpus)
{
preempt_disable();
- nmi_watchdog_default();
smp_cpu_index_default();
current_cpu_data = boot_cpu_data;
cpu_callin_map = cpumask_of_cpu(0);
diff --git a/include/asm-x86/nmi.h b/include/asm-x86/nmi.h
index f0e435dd38fbb..1348e542360f5 100644
--- a/include/asm-x86/nmi.h
+++ b/include/asm-x86/nmi.h
@@ -20,7 +20,6 @@ extern void default_do_nmi(struct pt_regs *);
#endif
extern void die_nmi(char *str, struct pt_regs *regs, int do_panic);
-extern void nmi_watchdog_default(void);
extern int check_nmi_watchdog(void);
extern int nmi_watchdog_enabled;
extern int avail_to_resrv_perfctr_nmi_bit(unsigned int);
@@ -38,12 +37,10 @@ extern int nmi_watchdog_tick(struct pt_regs *regs, unsigned reason);
extern atomic_t nmi_active;
extern unsigned int nmi_watchdog;
-#define NMI_DISABLED -1
#define NMI_NONE 0
#define NMI_IO_APIC 1
#define NMI_LOCAL_APIC 2
#define NMI_INVALID 3
-#define NMI_DEFAULT NMI_DISABLED
struct ctl_table;
struct file;
--
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