Commit 054ed634 authored by Tony Luck's avatar Tony Luck Committed by Jonathan Corbet
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Documentation/x86: Update split lock documentation 



commit b041b525 ("x86/split_lock: Make life miserable for split
lockers") added a delay and serialization of split locks. Commit
72720937 ("x86/split_lock: Add sysctl to control the misery mode")
provided a sysctl to turn off the misery.

Update the split lock documentation to describe the current state of
the code.

Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20230315225722.104607-1-tony.luck@intel.com


Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
parent 1aa63d4e

Documentation/x86/buslock.rst

+8 −2
Original line number Diff line number Diff line
@@ -53,8 +53,14 @@ parameter "split_lock_detect". Here is a summary of different options: 
|off	  	   |Do nothing			|Do nothing		|

+------------------+----------------------------+-----------------------+

|warn		   |Kernel OOPs			|Warn once per task and |

|(default)	   |Warn once per task and	|and continues to run.  |

|		   |disable future checking	|			|

|(default)	   |Warn once per task, add a	|and continues to run.  |

|		   |delay, add synchronization	|			|

|		   |to prevent more than one	|			|

|		   |core from executing a	|			|

|		   |split lock in parallel.	|			|

|		   |sysctl split_lock_mitigate	|			|

|		   |can be used to avoid the	|			|

|		   |delay and synchronization	|			|

|		   |When both features are	|			|

|		   |supported, warn in #AC	|			|

+------------------+----------------------------+-----------------------+