Commit 553f265f authored by Andi Kleen's avatar Andi Kleen Committed by Linus Torvalds
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[PATCH] x86_64: Don't run NMI watchdog during machine checks



Machine checks can stall the machine for a long time and
it's not good to trigger the nmi watchdog during that.
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent be56db61
......@@ -29,6 +29,8 @@
#define MISC_MCELOG_MINOR 227
#define NR_BANKS 6
atomic_t mce_entry;
static int mce_dont_init;
/* 0: always panic, 1: panic if deadlock possible, 2: try to avoid panic,
......@@ -172,10 +174,12 @@ void do_machine_check(struct pt_regs * regs, long error_code)
int i;
int panicm_found = 0;
atomic_inc(&mce_entry);
if (regs)
notify_die(DIE_NMI, "machine check", regs, error_code, 18, SIGKILL);
if (!banks)
return;
goto out2;
memset(&m, 0, sizeof(struct mce));
m.cpu = safe_smp_processor_id();
......@@ -266,6 +270,8 @@ void do_machine_check(struct pt_regs * regs, long error_code)
out:
/* Last thing done in the machine check exception to clear state. */
wrmsrl(MSR_IA32_MCG_STATUS, 0);
out2:
atomic_dec(&mce_entry);
}
/*
......
......@@ -34,6 +34,7 @@
#include <asm/proto.h>
#include <asm/kdebug.h>
#include <asm/local.h>
#include <asm/mce.h>
/*
* lapic_nmi_owner tracks the ownership of the lapic NMI hardware:
......@@ -480,6 +481,12 @@ void __kprobes nmi_watchdog_tick(struct pt_regs * regs, unsigned reason)
__get_cpu_var(nmi_touch) = 0;
touched = 1;
}
#ifdef CONFIG_X86_MCE
/* Could check oops_in_progress here too, but it's safer
not too */
if (atomic_read(&mce_entry) > 0)
touched = 1;
#endif
if (!touched && __get_cpu_var(last_irq_sum) == sum) {
/*
* Ayiee, looks like this CPU is stuck ...
......
......@@ -70,6 +70,9 @@ struct mce_log {
#define MCE_THRESHOLD_BASE MCE_EXTENDED_BANK + 1 /* MCE_AMD */
#define MCE_THRESHOLD_DRAM_ECC MCE_THRESHOLD_BASE + 4
#ifdef __KERNEL__
#include <asm/atomic.h>
void mce_log(struct mce *m);
#ifdef CONFIG_X86_MCE_INTEL
void mce_intel_feature_init(struct cpuinfo_x86 *c);
......@@ -87,4 +90,8 @@ static inline void mce_amd_feature_init(struct cpuinfo_x86 *c)
}
#endif
extern atomic_t mce_entry;
#endif
#endif
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