Merge master.kernel.org:/home/rmk/linux-2.6-mmc

[karo-tx-linux.git] / Documentation / x86_64 / boot-options.txt

diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt
index b9e6be00cadfbc1f2e767076c467ccb6f6ad28e6..ffe1c062088b9daa52954b2dd6054975f52b9a7b 100644 (file)
--- a/Documentation/x86_64/boot-options.txt
+++ b/Documentation/x86_64/boot-options.txt
@@ -6,6 +6,16 @@ only the AMD64 specific ones are listed here.
 Machine check
 
    mce=off disable machine check
+   mce=bootlog Enable logging of machine checks left over from booting.
+               Disabled by default because some BIOS leave bogus ones.
+               If your BIOS doesn't do that it's a good idea to enable though
+               to make sure you log even machine check events that result
+               in a reboot.
+   mce=tolerancelevel (number)
+               0: always panic, 1: panic if deadlock possible,
+               2: try to avoid panic, 3: never panic or exit (for testing)
+               default is 1
+               Can be also set using sysfs which is preferable.
 
    nomce (for compatibility with i386): same as mce=off
 
@@ -47,7 +57,7 @@ Timing
   notsc
   Don't use the CPU time stamp counter to read the wall time.
   This can be used to work around timing problems on multiprocessor systems
-  with not properly synchronized CPUs. Only useful with a SMP kernel
+  with not properly synchronized CPUs.
 
   report_lost_ticks
   Report when timer interrupts are lost because some code turned off
@@ -74,6 +84,9 @@ Idle loop
   event. This will make the CPUs eat a lot more power, but may be useful
   to get slightly better performance in multiprocessor benchmarks. It also
   makes some profiling using performance counters more accurate.
+  Please note that on systems with MONITOR/MWAIT support (like Intel EM64T
+  CPUs) this option has no performance advantage over the normal idle loop.
+  It may also interact badly with hyperthreading.
 
 Rebooting
 
@@ -178,6 +191,5 @@ Debugging
 Misc
 
   noreplacement  Don't replace instructions with more appropiate ones
-                                for the CPU. This may be useful on asymmetric MP systems
-                                where some CPU have less capabilities than the others.
-
+                for the CPU. This may be useful on asymmetric MP systems
+                where some CPU have less capabilities than the others.