[PATCH v6 8/8] x86/resctrl: Display hardware ids of resource groups

Babu Moger
2023-07-19T23:23:30Z

In x86, hardware uses CLOSID and an RMID to identify a control group and
a monitoring group respectively. When a user creates a control or monitor
group these details are not visible to the user. These details can help
debugging.

Add CLOSID(ctrl_hw_id) and RMID(mon_hw_id) to the control/monitor groups
display in resctrl interface. Users can see these details when resctrl
is mounted with "-o debug" option.

Other architectures do not use "CLOSID" and "RMID". Use the names
ctrl_hw_id and mon_hw_id to refer "CLOSID" and "RMID" respectively in an
effort to keep the naming generic.

For example:
$cat /sys/fs/resctrl/ctrl_grp1/ctrl_hw_id
1
$cat /sys/fs/resctrl/mon_groups/mon_grp1/mon_hw_id
3

Signed-off-by: Babu Moger <babu.moger@amd.com>
---
Documentation/arch/x86/resctrl.rst | 8 ++++++
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 46 ++++++++++++++++++++++++++++++++
2 files changed, 54 insertions(+)

diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
index 5a2346d2c561..41ad9b1f0c6a 100644
--- a/Documentation/arch/x86/resctrl.rst
+++ b/Documentation/arch/x86/resctrl.rst
@@ -351,6 +351,10 @@ 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":
@@ -364,6 +368,10 @@ 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/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 058c1dedb2d7..e8b35013d7c1 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -776,6 +776,38 @@ 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;
+}
+
+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

/*
@@ -1837,6 +1869,13 @@ 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_BASE | RFTYPE_DEBUG,
+ },
{
.name = "schemata",
.mode = 0644,
@@ -1860,6 +1899,13 @@ 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,
+ },

};