commit b041b525dab9 ("x86/split_lock: Make life miserable for split
lockers") added a delay and serialization of cplit 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 <[email protected]>
---
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 | |
+------------------+----------------------------+-----------------------+
--
2.39.2
Hi, Tony,
On 3/15/23 15:57, Tony Luck wrote:
> commit b041b525dab9 ("x86/split_lock: Make life miserable for split
> lockers") added a delay and serialization of cplit locks. Commit
s/cplit/split/
> 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 <[email protected]>
> ---
> 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 | |
> +------------------+----------------------------+-----------------------+
Other than the typo, looks good to me.
Thanks.
-Fenghua
On 15/03/2023 20:13, Fenghua Yu wrote:
> Hi, Tony,
>
> On 3/15/23 15:57, Tony Luck wrote:
>> commit b041b525dab9 ("x86/split_lock: Make life miserable for split
>> lockers") added a delay and serialization of cplit locks. Commit
> s/cplit/split/
>
>> 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 <[email protected]>
>> ---
>> 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 | |
>> +------------------+----------------------------+-----------------------+
>
> Other than the typo, looks good to me.
>
> Thanks.
>
> -Fenghua
Thanks for fixing the documentation Tony! Also looks great for me.
Cheers,
Guilherme
Tony Luck <[email protected]> writes:
> commit b041b525dab9 ("x86/split_lock: Make life miserable for split
> lockers") added a delay and serialization of cplit 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 <[email protected]>
> ---
> Documentation/x86/buslock.rst | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
Applied (with the typo pointed out by Fenghua fixed), thanks.
jon