[PATCH v4 6/7] x86/resctrl: Display CLOSID and RMID for the resctrl groups

Babu Moger
2023-04-17T23:36:00Z

When a user creates a control or monitor group, the CLOSID or RMID
are not visible to the user. It can help to debug the issues in some
cases. There are only available with "-o debug" option.

Add CLOSID(ctrl_hw_id) and RMID(mon_hw_id) to the control/monitor groups
display in resctrl interface.
$cat /sys/fs/resctrl/clos1/clos_hw_id
1
$cat /sys/fs/resctrl/mon_groups/mon1/mon_hw_id
3

Signed-off-by: Babu Moger <babu.moger@amd.com>
---
Documentation/x86/resctrl.rst | 17 ++++++++++++
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 44 ++++++++++++++++++++++++++++++++
2 files changed, 61 insertions(+)

diff --git a/Documentation/x86/resctrl.rst b/Documentation/x86/resctrl.rst
index be443251b484..5aff8c2beb08 100644
--- a/Documentation/x86/resctrl.rst
+++ b/Documentation/x86/resctrl.rst
@@ -345,6 +345,14 @@ 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. On x86, reading this file shows
+ the Class of Service (CLOS) id which acts as a resource control
+ tag on which the resources can be throttled. Kernel assigns a new
+ CLOSID a control group is created depending on the available
+ CLOSIDs. Multiple cores(or threads) or processes can share a
+ same CLOSID in a resctrl group.
+
When monitoring is enabled all MON groups will also contain:

"mon_data":
@@ -358,6 +366,15 @@ 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. On x86, reading this file shows
+ the Resource Monitoring ID (RMID) for monitoring the resource
+ utilization. Monitoring is performed by tagging each core (or
+ thread) or process via a RMID. Kernel assigns a new RMID when
+ a group is created depending on the available RMIDs. Multiple
+ cores (or threads) or processes can share a same RMID in a
+ resctrl group.
+
Resource allocation rules
-------------------------

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 0169821bc08c..15ded0dd5b09 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -782,6 +782,38 @@ 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

/*
@@ -1843,6 +1875,12 @@ 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,
+ },
{
.name = "schemata",
.mode = 0644,
@@ -1866,6 +1904,12 @@ 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,
+ },

};