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| author | Tony Luck <tony.luck@intel.com> | 2023-03-15 15:57:22 -0700 |
|---|---|---|
| committer | Jonathan Corbet <corbet@lwn.net> | 2023-03-23 12:02:35 -0600 |
| commit | 054ed6349c1bdc5f4575aea05a1d37ee45ec5fb7 (patch) | |
| tree | 21f239a7771afa6d5735594b6fb655410c724865 | |
| parent | 1aa63d4eb88167612be78e3b5a986b996544dca3 (diff) | |
| download | lwn-054ed6349c1bdc5f4575aea05a1d37ee45ec5fb7.tar.gz lwn-054ed6349c1bdc5f4575aea05a1d37ee45ec5fb7.zip | |
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 <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20230315225722.104607-1-tony.luck@intel.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
| -rw-r--r-- | Documentation/x86/buslock.rst | 10 |
1 files 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 | | +------------------+----------------------------+-----------------------+ |