On Fri, 15 Sep 2023, Babu Moger wrote:
> In x86, hardware uses CLOSID to identify a control group. When a user
> creates a control group this information is not visible to the user.
> It can help resctrl debugging.
>
> Add CLOSID(ctrl_hw_id) to the control groups display in resctrl
> interface. Users can see this detail when resctrl is mounted with
> "-o debug" option.
>
> Other architectures do not use "CLOSID". Use the names ctrl_hw_id
> to refer to "CLOSID" in an effort to keep the naming generic.
>
> For example:
> $cat /sys/fs/resctrl/ctrl_grp1/ctrl_hw_id
> 1
>
> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
> ---
> Documentation/arch/x86/resctrl.rst | 4 ++++
> arch/x86/kernel/cpu/resctrl/internal.h | 3 +++
> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 23 +++++++++++++++++++++++
> 3 files changed, 30 insertions(+)
>
> diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
> index 28d35aaa74b4..54691c8b832d 100644
> --- a/Documentation/arch/x86/resctrl.rst
> +++ b/Documentation/arch/x86/resctrl.rst
> @@ -352,6 +352,10 @@ When control is enabled all CTRL_MON groups will also contain:
> file. On successful pseudo-locked region creation the mode will
> automatically change to "pseudo-locked".
>
> +"ctrl_hw_id":
> + Available only with debug option. The identifier used by hardware
> + for the control group. On x86 this is the CLOSID.
> +
> When monitoring is enabled all MON groups will also contain:
>
> "mon_data":
> diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
> index 68d1b7147291..a07fa4329b65 100644
> --- a/arch/x86/kernel/cpu/resctrl/internal.h
> +++ b/arch/x86/kernel/cpu/resctrl/internal.h
> @@ -299,6 +299,9 @@ struct rdtgroup {
> * --> RFTYPE_CTRL (Files only for CTRL group)
> * Files: mode, schemata, size
> *
> + * --> RFTYPE_DEBUG (Files to help resctrl debugging)
> + * File: ctrl_hw_id
> + *
> */
> #define RFTYPE_INFO BIT(0)
> #define RFTYPE_BASE BIT(1)
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index 150105c21fee..953b082cec8a 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -779,6 +779,22 @@ static int rdtgroup_tasks_show(struct kernfs_open_file *of,
> return ret;
> }
>
> +static int rdtgroup_closid_show(struct kernfs_open_file *of,
> + struct seq_file *s, void *v)
> +{
> + struct rdtgroup *rdtgrp;
> + int ret = 0;
> +
> + rdtgrp = rdtgroup_kn_lock_live(of->kn);
> + if (rdtgrp)
> + seq_printf(s, "%u\n", rdtgrp->closid);
> + else
> + ret = -ENOENT;
> + rdtgroup_kn_unlock(of->kn);
> +
> + return ret;
> +}
> +
> #ifdef CONFIG_PROC_CPU_RESCTRL
>
> /*
> @@ -1863,6 +1879,13 @@ static struct rftype res_common_files[] = {
> .seq_show = rdtgroup_size_show,
> .fflags = RFTYPE_CTRL_BASE,
> },
> + {
> + .name = "ctrl_hw_id",
> + .mode = 0444,
> + .kf_ops = &rdtgroup_kf_single_ops,
> + .seq_show = rdtgroup_closid_show,
> + .fflags = RFTYPE_CTRL_BASE | RFTYPE_DEBUG,
> + },
>
> };
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
--
i.
