[PATCH v12 19/26] x86/resctrl: Add event configuration directory under info/L3_MON/

Babu Moger
2025-04-04T00:21:44Z

Create the configuration directory and files for mbm_cntr_assign mode.
These configurations will be used to assign MBM events in mbm_cntr_assign
mode, with two default configurations created upon mounting.

Example:
$ cd /sys/fs/resctrl/
$ cat info/L3_MON/counter_configs/mbm_total_bytes/event_filter
local_reads, remote_reads, local_non_temporal_writes,
remote_non_temporal_writes, local_reads_slow_memory,
remote_reads_slow_memory, dirty_victim_writes_all

$ cat info/L3_MON/counter_configs/mbm_local_bytes/event_filter
local_reads, local_non_temporal_writes, local_reads_slow_memory

Signed-off-by: Babu Moger <babu.moger@amd.com>
---
v12: New patch to hold the MBM event configurations for mbm_cntr_assign mode.
---
Documentation/arch/x86/resctrl.rst | 29 ++++++++++
arch/x86/kernel/cpu/resctrl/internal.h | 2 +
arch/x86/kernel/cpu/resctrl/monitor.c | 1 +
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 77 ++++++++++++++++++++++++++
4 files changed, 109 insertions(+)

diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
index 71ed1cfed33a..99f9f4b9b501 100644
--- a/Documentation/arch/x86/resctrl.rst
+++ b/Documentation/arch/x86/resctrl.rst
@@ -306,6 +306,35 @@ with the following files:
# cat /sys/fs/resctrl/info/L3_MON/available_mbm_cntrs
0=30;1=30

+"counter_configs:
+ The directory for storing event configuration files, which will be used to
+ assign counters when the mbm_cntr_assign mode is enabled.
+
+ Following types of events are supported:
+
+ ==== ========================= ============================================================
+ Bits Name Description
+ ==== ========================= ============================================================
+ 6 dirty_victim_writes_all Dirty Victims from the QOS domain to all types of memory
+ 5 remote_reads_slow_memory Reads to slow memory in the non-local NUMA domain
+ 4 local_reads_slow_memory Reads to slow memory in the local NUMA domain
+ 3 remote_non_temporal_writes Non-temporal writes to non-local NUMA domain
+ 2 local_non_temporal_writes Non-temporal writes to local NUMA domain
+ 1 remote_reads Reads to memory in the non-local NUMA domain
+ 0 local_reads Reads to memory in the local NUMA domain
+ ==== ========================= ==========================================================
+
+ Two default configurations, mbm_local_bytes and mbm_total_bytes, will be created
+ upon mounting.
+ ::
+
+ # cat /sys/fs/resctrl/info/L3_MON/counter_configs/mbm_total_bytes/event_filter
+ local_reads, remote_reads, local_non_temporal_writes, remote_non_temporal_writes,
+ local_reads_slow_memory, remote_reads_slow_memory, dirty_victim_writes_all
+
+ # cat /sys/fs/resctrl/info/L3_MON/counter_configs/mbm_local_bytes/event_filter
+ local_reads, local_non_temporal_writes, local_reads_slow_memory
+
"max_threshold_occupancy":
Read/write file provides the largest value (in
bytes) at which a previously used LLC_occupancy
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index b7d1a59f09f8..a943450bf2c8 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -282,11 +282,13 @@ struct mbm_cntr_cfg {
#define RFTYPE_RES_CACHE BIT(8)
#define RFTYPE_RES_MB BIT(9)
#define RFTYPE_DEBUG BIT(10)
+#define RFTYPE_CONFIG BIT(11)
#define RFTYPE_CTRL_INFO (RFTYPE_INFO | RFTYPE_CTRL)
#define RFTYPE_MON_INFO (RFTYPE_INFO | RFTYPE_MON)
#define RFTYPE_TOP_INFO (RFTYPE_INFO | RFTYPE_TOP)
#define RFTYPE_CTRL_BASE (RFTYPE_BASE | RFTYPE_CTRL)
#define RFTYPE_MON_BASE (RFTYPE_BASE | RFTYPE_MON)
+#define RFTYPE_MON_CONFIG (RFTYPE_CONFIG | RFTYPE_MON)

/* List of all resource groups */
extern struct list_head rdt_all_groups;
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 58476c065921..4525295b1725 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -1264,6 +1264,7 @@ int __init resctrl_mon_resource_init(void)
if (r->mon.mbm_cntr_assignable) {
resctrl_file_fflags_init("num_mbm_cntrs", RFTYPE_MON_INFO);
resctrl_file_fflags_init("available_mbm_cntrs", RFTYPE_MON_INFO);
+ resctrl_file_fflags_init("event_filter", RFTYPE_MON_CONFIG);
}

return 0;
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index aba23e2096db..b2122a1dd36c 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1907,6 +1907,25 @@ static ssize_t mbm_local_bytes_config_write(struct kernfs_open_file *of,
return ret ?: nbytes;
}

+static int event_filter_show(struct kernfs_open_file *of, struct seq_file *seq, void *v)
+{
+ struct mbm_assign_config *assign_config = of->kn->parent->priv;
+ bool sep = false;
+ int i;
+
+ for (i = 0; i < NUM_MBM_EVT_VALUES; i++) {
+ if (assign_config->val & mbm_evt_values[i].evt_val) {
+ if (sep)
+ seq_puts(seq, ", ");
+ seq_printf(seq, "%s", mbm_evt_values[i].evt_name);
+ sep = true;
+ }
+ }
+ seq_puts(seq, "\n");
+
+ return 0;
+}
+
/* rdtgroup information files for one cache resource. */
static struct rftype res_common_files[] = {
{
@@ -2019,6 +2038,12 @@ static struct rftype res_common_files[] = {
.seq_show = mbm_local_bytes_config_show,
.write = mbm_local_bytes_config_write,
},
+ {
+ .name = "event_filter",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = event_filter_show,
+ },
{
.name = "mbm_assign_mode",
.mode = 0444,
@@ -2314,6 +2339,52 @@ static int rdtgroup_mkdir_info_resdir(void *priv, char *name,
return ret;
}

+static int resctrl_mkdir_info_configs(void *priv, char *name, unsigned long fflags)
+{
+ struct kernfs_node *l3_mon_kn, *kn_subdir, *kn_subdir2;
+ int ret, i;
+
+ l3_mon_kn = kernfs_find_and_get(kn_info, name);
+ if (!l3_mon_kn)
+ return -ENOENT;
+
+ kn_subdir = kernfs_create_dir(l3_mon_kn, "counter_configs", l3_mon_kn->mode, priv);
+ if (IS_ERR(kn_subdir)) {
+ kernfs_put(l3_mon_kn);
+ return PTR_ERR(kn_subdir);
+ }
+
+ ret = rdtgroup_kn_set_ugid(kn_subdir);
+ if (ret) {
+ kernfs_put(l3_mon_kn);
+ return ret;
+ }
+
+ for (i = 0; i < NUM_MBM_ASSIGN_CONFIGS; i++) {
+ kn_subdir2 = kernfs_create_dir(kn_subdir, mbm_assign_configs[i].name,
+ kn_subdir->mode, &mbm_assign_configs[i]);
+ if (IS_ERR(kn_subdir)) {
+ ret = PTR_ERR(kn_subdir2);
+ goto config_out;
+ }
+
+ ret = rdtgroup_kn_set_ugid(kn_subdir2);
+ if (ret)
+ goto config_out;
+
+ ret = rdtgroup_add_files(kn_subdir2, fflags);
+ if (!ret)
+ kernfs_activate(kn_subdir);
+ }
+
+config_out:
+ kernfs_put(l3_mon_kn);
+ if (ret)
+ kernfs_remove(kn_subdir);
+
+ return ret;
+}
+
static unsigned long fflags_from_resource(struct rdt_resource *r)
{
switch (r->rid) {
@@ -2360,6 +2431,12 @@ static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
ret = rdtgroup_mkdir_info_resdir(r, name, fflags);
if (ret)
goto out_destroy;
+
+ if (r->mon.mbm_cntr_assignable) {
+ ret = resctrl_mkdir_info_configs(r, name, RFTYPE_MON_CONFIG);
+ if (ret)
+ goto out_destroy;
+ }
}

ret = rdtgroup_kn_set_ugid(kn_info);
--
2.34.1