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>
Tested-by: Peter Newman <peternewman@xxxxxxxxxx>
Reviewed-by: Peter Newman <peternewman@xxxxxxxxxx>
Tested-by: Tan Shaopeng <tan.shaopeng@xxxxxxxxxxxxxx>
Reviewed-by: Tan Shaopeng <tan.shaopeng@xxxxxxxxxxxxxx>
Reviewed-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
---
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 eda5da9ab81f..a25407fde6fc 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 for MON group)
+ *
+ * --> RFTYPE_DEBUG (Files to help resctrl debugging)
+ * File: mon_hw_id
+ *
* --> RFTYPE_CTRL (Files 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,
--
2.34.1
