Re: [PATCH v21 13/18] x86/resctrl: Handle removing directories in Sub-NUMA Cluster (SNC) mode

[Reinette Chatre]

Hi Tony,

On 6/21/24 3:38 PM, Tony Luck wrote:
> In SNC mode there are multiple subdirectories in each L3 level monitor
> directory (one for each SNC node). If all the CPUs in an SNC node are
> taken offline, just remove the SNC directory for that node. In
> non-SNC mode, or when the last SNC node directory is removed,
> remove the L3 monitor directory.
>
> Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
> ---
>   arch/x86/kernel/cpu/resctrl/rdtgroup.c | 39 +++++++++++++++++++++-----
>   1 file changed, 32 insertions(+), 7 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index 2591a6876232..14482d88b68c 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -3008,20 +3008,45 @@ static int mon_addfile(struct kernfs_node *parent_kn, const char *name,
>   
>   /*
>    * Remove all subdirectories of mon_data of ctrl_mon groups
> - * and monitor groups with given domain id.
> + * and monitor groups for the given domain. In SNC mode just

I do not think we want the Intel architecture specific "SNC" to be
a "mode" of resctrl fs. That means all architectures need a "SNC mode".
How about something like (please feel free to improve):
	Remove files and directories containing "sum" of domain data
	when last domain being summed is removed.


With mention of "SNC mode" removed:
| Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>

Reinette