On Fri, 15 Sep 2023, Babu Moger wrote:
> In x86, hardware uses RMID to identify a monitoring group. When a user
> creates a monitor group these details are not visible. These details
> can help resctrl debugging.
>
> Add RMID(mon_hw_id) to the monitor groups display in resctrl interface.
> Users can see these details when resctrl is mounted with "-o debug" option.
>
> Other architectures do not use "RMID". Use the name mon_hw_id to refer
> to "RMID" in an effort to keep the naming generic.
>
> For example:
> $cat /sys/fs/resctrl/mon_groups/mon_grp1/mon_hw_id
> 3
>
> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
> ---
> Documentation/arch/x86/resctrl.rst | 4 ++++
> arch/x86/kernel/cpu/resctrl/internal.h | 5 +++++
> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 23 +++++++++++++++++++++++
> 3 files changed, 32 insertions(+)
>
> diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
> index 54691c8b832d..98b0eb509ed4 100644
> --- a/Documentation/arch/x86/resctrl.rst
> +++ b/Documentation/arch/x86/resctrl.rst
> @@ -369,6 +369,10 @@ When monitoring is enabled all MON groups will also contain:
> the sum for all tasks in the CTRL_MON group and all tasks in
> MON groups. Please see example section for more details on usage.
>
> +"mon_hw_id":
> + Available only with debug option. The identifier used by hardware
> + for the monitor group. On x86 this is the RMID.
> +
> Resource allocation rules
> -------------------------
>
> diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
> index a07fa4329b65..b4910892b0a6 100644
> --- a/arch/x86/kernel/cpu/resctrl/internal.h
> +++ b/arch/x86/kernel/cpu/resctrl/internal.h
> @@ -296,6 +296,11 @@ struct rdtgroup {
> * --> RFTYPE_BASE (Files common for both MON and CTRL groups)
> * Files: cpus, cpus_list, tasks
> *
> + * --> RFTYPE_MON (Files only for MON group)
> + *
> + * --> RFTYPE_DEBUG (Files to help resctrl debugging)
> + * File: mon_hw_id
> + *
> * --> RFTYPE_CTRL (Files only for CTRL group)
> * Files: mode, schemata, size
> *
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index 55d1b90f460e..ef4b18091e5d 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -795,6 +795,22 @@ static int rdtgroup_closid_show(struct kernfs_open_file *of,
> return ret;
> }
>
> +static int rdtgroup_rmid_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->mon.rmid);
> + else
> + ret = -ENOENT;
> + rdtgroup_kn_unlock(of->kn);
> +
> + return ret;
> +}
> +
> #ifdef CONFIG_PROC_CPU_RESCTRL
>
> /*
> @@ -1856,6 +1872,13 @@ static struct rftype res_common_files[] = {
> .seq_show = rdtgroup_tasks_show,
> .fflags = RFTYPE_BASE,
> },
> + {
> + .name = "mon_hw_id",
> + .mode = 0444,
> + .kf_ops = &rdtgroup_kf_single_ops,
> + .seq_show = rdtgroup_rmid_show,
> + .fflags = RFTYPE_MON_BASE | RFTYPE_DEBUG,
> + },
> {
> .name = "schemata",
> .mode = 0644,
>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
--
i.
