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>

1 files changed, 1 insertions, 9 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index cdd2a6e8a3b7..5e55e4623ab5 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -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