x86, mce: improve documentation

Document that check_interval set to 0 means no polling.
Noticed by Hidetoshi Seto

Also add a reference from boot options to the sysfs tunables

Acked-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

2 files changed, 5 insertions, 1 deletions

diff --git a/Documentation/x86/x86_64/boot-options.txt b/Documentation/x86/x86_64/boot-options.txt
index 34c13040a718..63fca718256e 100644
--- a/Documentation/x86/x86_64/boot-options.txt
+++ b/Documentation/x86/x86_64/boot-options.txt
@@ -5,6 +5,8 @@ only the AMD64 specific ones are listed here.
 
 Machine check
 
+   Please see Documentation/x86/x86_64/machinecheck for sysfs runtime tunables.
+
    mce=off disable machine check
    mce=bootlog Enable logging of machine checks left over from booting.
                Disabled by default on AMD because some BIOS leave bogus ones.
diff --git a/Documentation/x86/x86_64/machinecheck b/Documentation/x86/x86_64/machinecheck
index a05e58e7b159..a4fdb25446e0 100644
--- a/Documentation/x86/x86_64/machinecheck
+++ b/Documentation/x86/x86_64/machinecheck
@@ -41,7 +41,9 @@ check_interval
         the polling interval.  When the poller stops finding MCEs, it
         triggers an exponential backoff (poll less often) on the polling
         interval. The check_interval variable is both the initial and
-        maximum polling interval.
+        maximum polling interval. 0 means no polling for corrected machine
+        check errors (but some corrected errors might be still reported
+        in other ways)
 
 tolerant
         Tolerance level. When a machine check exception occurs for a non