linux-kernel - Re: [PATCH] Documentation/x86: Update split lock documentation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 15 Mar 2023 16:13:24 -0700
From:   Fenghua Yu <fenghua.yu@...el.com>
To:     Tony Luck <tony.luck@...el.com>, Jonathan Corbet <corbet@....net>
CC:     "Guilherme G. Piccoli" <gpiccoli@...lia.com>, <x86@...nel.org>,
        <linux-doc@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <patches@...ts.linux.dev>
Subject: Re: [PATCH] Documentation/x86: Update split lock documentation

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 <tony.luck@...el.com>
> ---
>   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