From 054ed6349c1bdc5f4575aea05a1d37ee45ec5fb7 Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Wed, 15 Mar 2023 15:57:22 -0700 Subject: [PATCH] Documentation/x86: Update split lock documentation commit b041b525dab9 ("x86/split_lock: Make life miserable for split lockers") added a delay and serialization of split locks. Commit 727209376f49 ("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: Tony Luck Link: https://lore.kernel.org/r/20230315225722.104607-1-tony.luck@intel.com Signed-off-by: Jonathan Corbet --- Documentation/x86/buslock.rst | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/Documentation/x86/buslock.rst b/Documentation/x86/buslock.rst index 7c051e714943..31ec0ef78086 100644 --- a/Documentation/x86/buslock.rst +++ b/Documentation/x86/buslock.rst @@ -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 | | +------------------+----------------------------+-----------------------+ -- 2.34.1