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x86, NMI: Add back unknown_nmi_panic and nmi_watchdog sysctls 

Originally adapted from Huang Ying's patch which moved the
unknown_nmi_panic to the traps.c file.  Because the old nmi
watchdog was deleted before this change happened, the
unknown_nmi_panic sysctl was lost.  This re-adds it.

Also, the nmi_watchdog sysctl was re-implemented and its
documentation updated accordingly.

Patch-inspired-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Cc: fweisbec@gmail.com
LKML-Reference: <1291068437-5331-3-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Don Zickus 2010-11-29 17:07:17 -05:00 committed by Ingo Molnar
parent 96a84c20d6
commit 5dc3055879
6 changed files with 30 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
Documentation/kernel-parameters.txt
View File

@ -1579,20 +1579,12 @@ and is between 256 and 4096 characters. It is defined in the file
nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels
Format: [panic,][num]
Valid num: 0,1,2
Valid num: 0
0 - turn nmi_watchdog off
1 - use the IO-APIC timer for the NMI watchdog
2 - use the local APIC for the NMI watchdog using
a performance counter. Note: This will use one
performance counter and the local APIC's performance
vector.
When panic is specified, panic when an NMI watchdog
timeout occurs.
This is useful when you use a panic=... timeout and
need the box quickly up again.
Instead of 1 and 2 it is possible to use the following
symbolic names: lapic and ioapic
Example: nmi_watchdog=2 or nmi_watchdog=panic,lapic
netpoll.carrier_timeout=
[NET] Specifies amount of time (in seconds) that

3
arch/x86/kernel/apic/hw_nmi.c
View File

@ -99,6 +99,3 @@ static int __init register_trigger_all_cpu_backtrace(void)
}
early_initcall(register_trigger_all_cpu_backtrace);
#endif
/* STUB calls to mimic old nmi_watchdog behaviour */
int unknown_nmi_panic;

16
arch/x86/kernel/traps.c
View File

@ -83,6 +83,8 @@ EXPORT_SYMBOL_GPL(used_vectors);
static int ignore_nmis;
int unknown_nmi_panic;
static inline void conditional_sti(struct pt_regs *regs)
{
if (regs->flags & X86_EFLAGS_IF)
@ -300,6 +302,13 @@ gp_in_kernel:
die("general protection fault", regs, error_code);
}
static int __init setup_unknown_nmi_panic(char *str)
{
unknown_nmi_panic = 1;
return 1;
}
__setup("unknown_nmi_panic", setup_unknown_nmi_panic);
static notrace __kprobes void
mem_parity_error(unsigned char reason, struct pt_regs *regs)
{
@ -371,7 +380,7 @@ unknown_nmi_error(unsigned char reason, struct pt_regs *regs)
reason, smp_processor_id());
printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");
if (panic_on_unrecovered_nmi)
if (unknown_nmi_panic || panic_on_unrecovered_nmi)
panic("NMI: Not continuing");
printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
@ -397,11 +406,8 @@ static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT)
== NOTIFY_STOP)
return;
unknown_nmi_error(reason, regs);
#else
unknown_nmi_error(reason, regs);
#endif
unknown_nmi_error(reason, regs);
return;
}

16
kernel/sysctl.c
View File

@ -745,6 +745,22 @@ static struct ctl_table kern_table[] = {
.extra1 = &zero,
.extra2 = &one,
},
{
.procname = "nmi_watchdog",
.data = &watchdog_enabled,
.maxlen = sizeof (int),
.mode = 0644,
.proc_handler = proc_dowatchdog_enabled,
},
#endif
#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
{
.procname = "unknown_nmi_panic",
.data = &unknown_nmi_panic,
.maxlen = sizeof (int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
#endif
#if defined(CONFIG_X86)
{

1
kernel/sysctl_binary.c
View File

@ -136,7 +136,6 @@ static const struct bin_table bin_kern_table[] = {
{ CTL_INT, KERN_IA64_UNALIGNED, "ignore-unaligned-usertrap" },
{ CTL_INT, KERN_COMPAT_LOG, "compat-log" },
{ CTL_INT, KERN_MAX_LOCK_DEPTH, "max_lock_depth" },
{ CTL_INT, KERN_NMI_WATCHDOG, "nmi_watchdog" },
{ CTL_INT, KERN_PANIC_ON_NMI, "panic_on_unrecovered_nmi" },
{}
};

2
kernel/watchdog.c
View File

@ -57,6 +57,8 @@ static int __init hardlockup_panic_setup(char *str)
{
if (!strncmp(str, "panic", 5))
hardlockup_panic = 1;
else if (!strncmp(str, "0", 1))
no_watchdog = 1;
return 1;
}
__setup("nmi_watchdog=", hardlockup_panic_setup);