Messages in this thread | | | Date | Sat, 3 Sep 2011 01:14:55 +0200 | Subject | Re: [PATCH 08/13] xen/pvticketlock: disable interrupts while blocking | From | "Andi Kleen" <> |
| |
> But, erm, does that even make sense? I'm assuming the NMI reason port > tells the CPU why it got an NMI. If multiple CPUs can get NMIs and > there's only a single reason port, then doesn't that mean that either 1) > they all got the NMI for the same reason, or 2) having a single port is > inherently racy? How does the locking actually work there?
All the code to determine NMI reasons is inherently racy, and each new NMI user makes it worse.
-Andi
| |