Re: [PATCH -next] cgroup/misc: Introduce misc.peak

[Randy Dunlap <rdunlap@infradead.org>]

Hi--

On 7/1/24 5:52 AM, Xiu Jianfeng wrote:
> Introduce misc.peak to record the historical maximum usage of the
> resource, as in some scenarios the value of misc.max could be
> adjusted based on the peak usage of the resource.
> 
> Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
> ---
>  Documentation/admin-guide/cgroup-v2.rst |  9 ++++++++
>  include/linux/misc_cgroup.h             |  2 ++
>  kernel/cgroup/misc.c                    | 29 +++++++++++++++++++++++++
>  3 files changed, 40 insertions(+)
> 
> diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
> index ae0fdb6fc618..48ae30f2d9ab 100644
> --- a/Documentation/admin-guide/cgroup-v2.rst
> +++ b/Documentation/admin-guide/cgroup-v2.rst
> @@ -2646,6 +2646,15 @@ Miscellaneous controller provides 3 interface files. If two misc resources (res_
>  	  res_a 3
>  	  res_b 0
>  
> +  misc.peak
> +        A read-only flat-keyed file shown in the all cgroups.  It shows

	                               shown in all cgroups. It shows

> +        the historical maximum usage of the resources in the cgroup and
> +        its children.::
> +
> +	  $ cat misc.peak
> +	  res_a 10
> +	  res_b 8
> +
>    misc.max
>          A read-write flat-keyed file shown in the non root cgroups. Allowed
>          maximum usage of the resources in the cgroup and its children.::
> diff --git a/include/linux/misc_cgroup.h b/include/linux/misc_cgroup.h
> index e799b1f8d05b..8aa69818291e 100644
> --- a/include/linux/misc_cgroup.h
> +++ b/include/linux/misc_cgroup.h
> @@ -30,11 +30,13 @@ struct misc_cg;
>  /**
>   * struct misc_res: Per cgroup per misc type resource
>   * @max: Maximum limit on the resource.
> + * $watermark: Historical maximum usage of the resource.

      @watermark:

>   * @usage: Current usage of the resource.
>   * @events: Number of times, the resource limit exceeded.
>   */
>  struct misc_res {
>  	u64 max;
> +	u64 watermark;
>  	atomic64_t usage;
>  	atomic64_t events;
>  };


-- 
~Randy