[PATCH v7 08/12] x86/resctrl: Add sysfs interface to read mbm_local_bytes event configuration

Babu Moger
2022-10-17T22:27:55Z

The current event configuration can be viewed by the user by reading
the configuration file /sys/fs/resctrl/info/L3_MON/mbm_local_config.
The event configuration settings are domain specific and will affect
all the CPUs in the domain.

Following are the types of events supported:
==== ===========================================================
Bits Description
==== ===========================================================
6 Dirty Victims from the QOS domain to all types of memory
5 Reads to slow memory in the non-local NUMA domain
4 Reads to slow memory in the local NUMA domain
3 Non-temporal writes to non-local NUMA domain
2 Non-temporal writes to local NUMA domain
1 Reads to memory in the non-local NUMA domain
0 Reads to memory in the local NUMA domain
==== ===========================================================

By default, the mbm_local_bytes configuration is set to 0x15 to count
all the local event types.

For example:
$cat /sys/fs/resctrl/info/L3_MON/mbm_local_config
0=0x15;1=0x15;2=0x15;3=0x15

In this case the event mbm_local_bytes is currently configured with
0x15 on domains 0 to 3.

Signed-off-by: Babu Moger <babu.moger@amd.com>
---
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 0982845594d0..305fb0475970 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1484,6 +1484,16 @@ static int mbm_total_config_show(struct kernfs_open_file *of,
return 0;
}

+static int mbm_local_config_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct rdt_resource *r = of->kn->parent->priv;
+
+ mbm_config_show(seq, r, QOS_L3_MBM_LOCAL_EVENT_ID);
+
+ return 0;
+}
+
/* rdtgroup information files for one cache resource. */
static struct rftype res_common_files[] = {
{
@@ -1588,6 +1598,12 @@ static struct rftype res_common_files[] = {
.kf_ops = &rdtgroup_kf_single_ops,
.seq_show = mbm_total_config_show,
},
+ {
+ .name = "mbm_local_config",
+ .mode = 0644,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = mbm_local_config_show,
+ },
{
.name = "cpus",
.mode = 0644,
@@ -1701,6 +1717,10 @@ void __init mbm_config_rftype_init(void)
rft = rdtgroup_get_rftype_by_name("mbm_total_config");
if (rft)
rft->fflags = RF_MON_INFO | RFTYPE_RES_CACHE;
+
+ rft = rdtgroup_get_rftype_by_name("mbm_local_config");
+ if (rft)
+ rft->fflags = RF_MON_INFO | RFTYPE_RES_CACHE;
}

/**