x86, mce: add machine check exception count in /proc/interrupts

Useful for debugging, but it's also good general policy
to have a counter for all special interrupts there. This makes it easier
to diagnose where a CPU is spending its time.

[ Impact: feature, debugging tool ]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 1d0aa9c4e15b..287268d21836 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -57,6 +57,8 @@ int				mce_disabled;
 
 atomic_t mce_entry;
 
+DEFINE_PER_CPU(unsigned, mce_exception_count);
+
 /*
  * Tolerant levels:
  *   0: always panic on uncorrected errors, log corrected errors
@@ -359,6 +361,8 @@ void do_machine_check(struct pt_regs *regs, long error_code)
 
         atomic_inc(&mce_entry);
 
+        __get_cpu_var(mce_exception_count)++;
+
         if (notify_die(DIE_NMI, "machine check", regs, error_code,
                            18, SIGKILL) == NOTIFY_STOP)
                 goto out;