The mbm_cntr_assign mode provides an option to the user to assign a
counter to an RMID, event pair and monitor the bandwidth as long as
the counter is assigned.
Introduce a configuration option to automatically assign counter IDs
when a resctrl group is created, provided the counters are available.
By default, this option is enabled at boot.
Suggested-by: Peter Newman <peternewman@xxxxxxxxxx>
Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
v13: Added Suggested-by tag.
Resolved conflicts caused by the recent FS/ARCH code restructure.
The rdtgroup.c/monitor.c file has now been split between the FS and ARCH directories.
v12: New patch. Added after the discussion on the list.
https://lore.kernel.org/lkml/CALPaoCh8siZKjL_3yvOYGL4cF_n_38KpUFgHVGbQ86nD+Q2_SA@xxxxxxxxxxxxxx/
---
Documentation/filesystems/resctrl.rst | 10 ++++++
fs/resctrl/monitor.c | 2 ++
fs/resctrl/rdtgroup.c | 44 +++++++++++++++++++++++++--
include/linux/resctrl.h | 2 ++
4 files changed, 56 insertions(+), 2 deletions(-)
diff --git a/Documentation/filesystems/resctrl.rst b/Documentation/filesystems/resctrl.rst
index 9923276826db..356f1f918a86 100644
--- a/Documentation/filesystems/resctrl.rst
+++ b/Documentation/filesystems/resctrl.rst
@@ -348,6 +348,16 @@ with the following files:
# cat /sys/fs/resctrl/info/L3_MON/counter_configs/mbm_total_bytes/event_filter
local_reads, local_non_temporal_writes
+"mbm_assign_on_mkdir":
+ Automatically assign the monitoring counters on resctrl group creation
+ if the counters are available. It is enabled by default on boot and users
+ can disable by writing to the interface.
+ ::
+
+ # echo 0 > /sys/fs/resctrl/info/L3_MON/mbm_assign_on_mkdir
+ # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_on_mkdir
+ 0
+
"max_threshold_occupancy":
Read/write file provides the largest value (in
bytes) at which a previously used LLC_occupancy
diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c
index 1f72249a5c93..5f6c4b662f3b 100644
--- a/fs/resctrl/monitor.c
+++ b/fs/resctrl/monitor.c
@@ -933,6 +933,8 @@ int resctrl_mon_resource_init(void)
resctrl_file_fflags_init("available_mbm_cntrs",
RFTYPE_MON_INFO | RFTYPE_RES_CACHE);
resctrl_file_fflags_init("event_filter", RFTYPE_ASSIGN_CONFIG);
+ resctrl_file_fflags_init("mbm_assign_on_mkdir", RFTYPE_MON_INFO |
+ RFTYPE_RES_CACHE);
}
return 0;
diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
index 8c498b41be5d..0093b323d858 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -2035,8 +2035,8 @@ static ssize_t event_filter_write(struct kernfs_open_file *of, char *buf,
}
ret = resctrl_process_configs(buf, &evt_cfg);
- if (!ret && mevt->evt_val != evt_cfg) {
- mevt->evt_val = evt_cfg;
+ if (!ret && mevt->evt_cfg != evt_cfg) {
+ mevt->evt_cfg = evt_cfg;
resctrl_update_assign(r, mevt->evtid, evt_cfg);
}
@@ -2047,6 +2047,39 @@ static ssize_t event_filter_write(struct kernfs_open_file *of, char *buf,
return ret ?: nbytes;
}
+static int resctrl_mbm_assign_on_mkdir_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v)
+{
+ struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
+
+ seq_printf(s, "%u\n", r->mon.mbm_assign_on_mkdir);
+
+ return 0;
+}
+
+static ssize_t resctrl_mbm_assign_on_mkdir_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
+ bool value;
+ int ret;
+
+ ret = kstrtobool(buf, &value);
+ if (ret)
+ return ret;
+
+ cpus_read_lock();
+ mutex_lock(&rdtgroup_mutex);
+ rdt_last_cmd_clear();
+
+ r->mon.mbm_assign_on_mkdir = value;
+
+ mutex_unlock(&rdtgroup_mutex);
+ cpus_read_unlock();
+
+ return ret ?: nbytes;
+}
+
/* rdtgroup information files for one cache resource. */
static struct rftype res_common_files[] = {
{
@@ -2056,6 +2089,13 @@ static struct rftype res_common_files[] = {
.seq_show = rdt_last_cmd_status_show,
.fflags = RFTYPE_TOP_INFO,
},
+ {
+ .name = "mbm_assign_on_mkdir",
+ .mode = 0644,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = resctrl_mbm_assign_on_mkdir_show,
+ .write = resctrl_mbm_assign_on_mkdir_write,
+ },
{
.name = "num_closids",
.mode = 0444,
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index cd24d1577e0a..d6435abdde7b 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -278,6 +278,7 @@ enum resctrl_schema_fmt {
* monitoring events can be configured.
* @num_mbm_cntrs: Number of assignable monitoring counters
* @mbm_cntr_assignable:Is system capable of supporting monitor assignment?
+ * @mbm_assign_on_mkdir:Auto enable monitor assignment on mkdir?
* @evt_list: List of monitoring events
*/
struct resctrl_mon {
@@ -285,6 +286,7 @@ struct resctrl_mon {
unsigned int mbm_cfg_mask;
int num_mbm_cntrs;
bool mbm_cntr_assignable;
+ bool mbm_assign_on_mkdir;
struct list_head evt_list;
};
--
2.34.1
