1 files changed, 12 insertions, 0 deletions

diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt
index 9c5fc15d03d1..153740f460a6 100644
--- a/Documentation/x86_64/boot-options.txt
+++ b/Documentation/x86_64/boot-options.txt
@@ -40,6 +40,18 @@ APICs
    no_timer_check Don't check the IO-APIC timer. This can work around
                  problems with incorrect timer initialization on some boards.
 
+   apicmaintimer Run time keeping from the local APIC timer instead
+                 of using the PIT/HPET interrupt for this. This is useful
+                 when the PIT/HPET interrupts are unreliable.
+
+   noapicmaintimer  Don't do time keeping using the APIC timer.
+                 Useful when this option was auto selected, but doesn't work.
+
+   apicpmtimer
+                 Do APIC timer calibration using the pmtimer. Implies
+                 apicmaintimer. Useful when your PIT timer is totally
+                 broken.
+
 Early Console
 
    syntax: earlyprintk=vga