On Wed, 6 Jul 2016 07:03:43 -0500
Corey Minyard [off-list ref] wrote:

quoted

---

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index aaf4b9b94f38..cc70d98a30f6 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c

@@ -1391,7 +1391,8 @@ static int mce_notify_work_init(void)
  
  static void mce_notify_work(void)
  {
-	wake_up_process(mce_notify_helper);
+	if (mce_notify_helper)
+		wake_up_process(mce_notify_helper);
  }

Actually, this appears to be the fix in 4.6-rt.

quoted

  #else
  static void mce_notify_work(void)

 

I did think about that option, but I'm not sure why the current RT patch
has that as a separate bool.

This appears to come in here:

http://www.spinics.net/lists/linux-rt-users/msg12779.html

I'm copying Sebastian, who appears to be the original source of this
change.

You can see why this is different by looking at the commit that changed
it. Or this email:

 lkml.kernel.org/r/1365704626.9609.55.camel@gandalf.local.home

-- Steve