Event: A valid MBM event in the
/sys/fs/resctrl/info/L3_MON/event_configs directory.
- Domain ID: A valid domain ID.
+ Domain ID: A valid domain ID. When writing, '*' applies the changes
+ to all the domains.
Assignment states:
mbm_total_bytes:0=e;1=e
mbm_local_bytes:0=e;1=e
+ Assignments can be modified by writing to the interface.
+
+ Examples:
+
+ To unassign the counter associated with the mbm_total_bytes event on domain 0:
+ ::
+
+ # echo "mbm_total_bytes:0=_" > /sys/fs/resctrl/mbm_L3_assignments
+ # cat /sys/fs/resctrl/mbm_L3_assignments
+ mbm_total_bytes:0=_;1=e
+ mbm_local_bytes:0=e;1=e
+
+ To unassign the counter associated with the mbm_total_bytes event on all the domains:
+ ::
+
+ # echo "mbm_total_bytes:*=_" > /sys/fs/resctrl/mbm_L3_assignments
+ # cat /sys/fs/resctrl/mbm_L3_assignments
+ mbm_total_bytes:0=_;1=_
+ mbm_local_bytes:0=e;1=e
+
+ To assign a counter associated with the mbm_total_bytes event on all domains in
+ exclusive mode:
+ ::
+
+ # echo "mbm_total_bytes:*=e" > /sys/fs/resctrl/mbm_L3_assignments
+ # cat /sys/fs/resctrl/mbm_L3_assignments
+ mbm_total_bytes:0=e;1=e
+ mbm_local_bytes:0=e;1=e
+
When the "mba_MBps" mount option is used all CTRL_MON groups will also contain:
"mba_MBps_event":
# cat /sys/fs/resctrl/p1/mon_data/mon_L3_00/llc_occupancy
11234000
+
+Examples on working with mbm_assign_mode
+========================================
+
+a. Check if MBM counter assignment mode is supported.
+::
+
+ # mount -t resctrl resctrl /sys/fs/resctrl/
+
+ # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_mode
+ [mbm_event]
+ default
+
+The "mbm_event" mode is detected and enabled.
+
+b. Check how many assignable counters are supported.
+::
+
+ # cat /sys/fs/resctrl/info/L3_MON/num_mbm_cntrs
+ 0=32;1=32
+
+c. Check how many assignable counters are available for assignment in each domain.
+::
+
+ # cat /sys/fs/resctrl/info/L3_MON/available_mbm_cntrs
+ 0=30;1=30
+
+d. To list the default group's assign states.
+::
+
+ # cat /sys/fs/resctrl/mbm_L3_assignments
+ mbm_total_bytes:0=e;1=e
+ mbm_local_bytes:0=e;1=e
+
+e. To unassign the counter associated with the mbm_total_bytes event on domain 0.
+::
+
+ # echo "mbm_total_bytes:0=_" > /sys/fs/resctrl/mbm_L3_assignments
+ # cat /sys/fs/resctrl/mbm_L3_assignments
+ mbm_total_bytes:0=_;1=e
+ mbm_local_bytes:0=e;1=e
+
+f. To unassign the counter associated with the mbm_total_bytes event on all domains.
+::
+
+ # echo "mbm_total_bytes:*=_" > /sys/fs/resctrl/mbm_L3_assignments
+ # cat /sys/fs/resctrl/mbm_L3_assignment
+ mbm_total_bytes:0=_;1=_
+ mbm_local_bytes:0=e;1=e
+
+g. To assign a counter associated with the mbm_total_bytes event on all domains in
+exclusive mode.
+::
+
+ # echo "mbm_total_bytes:*=e" > /sys/fs/resctrl/mbm_L3_assignments
+ # cat /sys/fs/resctrl/mbm_L3_assignments
+ mbm_total_bytes:0=e;1=e
+ mbm_local_bytes:0=e;1=e
+
+h. Read the events mbm_total_bytes and mbm_local_bytes of the default group. There is
+no change in reading the events with the assignment.
+::
+
+ # cat /sys/fs/resctrl/mon_data/mon_L3_00/mbm_total_bytes
+ 779247936
+ # cat /sys/fs/resctrl/mon_data/mon_L3_01/mbm_total_bytes
+ 562324232
+ # cat /sys/fs/resctrl/mon_data/mon_L3_00/mbm_local_bytes
+ 212122123
+ # cat /sys/fs/resctrl/mon_data/mon_L3_01/mbm_local_bytes
+ 121212144
+
+i. Check the event configurations.
+::
+
+ # cat /sys/fs/resctrl/info/L3_MON/event_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/event_configs/mbm_local_bytes/event_filter
+ local_reads,local_non_temporal_writes,local_reads_slow_memory
+
+j. Change the event configuration for mbm_local_bytes.
+::
+
+ # echo "local_reads, local_non_temporal_writes, local_reads_slow_memory, remote_reads" >
+ /sys/fs/resctrl/info/L3_MON/event_configs/mbm_local_bytes/event_filter
+
+ # cat /sys/fs/resctrl/info/L3_MON/event_configs/mbm_local_bytes/event_filter
+ local_reads,local_non_temporal_writes,local_reads_slow_memory,remote_reads
+
+k. Now read the local events again. The first read may come back with "Unavailable"
+status. The subsequent read of mbm_local_bytes will display the current value.
+::
+
+ # cat /sys/fs/resctrl/mon_data/mon_L3_00/mbm_local_bytes
+ Unavailable
+ # cat /sys/fs/resctrl/mon_data/mon_L3_00/mbm_local_bytes
+ 2252323
+ # cat /sys/fs/resctrl/mon_data/mon_L3_01/mbm_local_bytes
+ Unavailable
+ # cat /sys/fs/resctrl/mon_data/mon_L3_01/mbm_local_bytes
+ 1566565
+
+l. Users have the option to go back to 'default' mbm_assign_mode if required. This can be
+done using the following command. Note that switching the mbm_assign_mode may reset all
+the MBM counters (and thus all MBM events) of all the resctrl groups.
+::
+
+ # echo "default" > /sys/fs/resctrl/info/L3_MON/mbm_assign_mode
+ # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_mode
+ mbm_event
+ [default]
+
+m. Unmount the resctrl filesystem.
+::
+
+ # umount /sys/fs/resctrl/
+
Intel RDT Errata
================
return ret;
}
+/*
+ * mbm_get_mon_event_by_name() - Return the mon_evt entry for the matching
+ * event name.
+ */
+static struct mon_evt *mbm_get_mon_event_by_name(struct rdt_resource *r, char *name)
+{
+ struct mon_evt *mevt;
+
+ for_each_mon_event(mevt) {
+ if (mevt->rid == r->rid && mevt->enabled &&
+ resctrl_is_mbm_event(mevt->evtid) &&
+ !strcmp(mevt->name, name))
+ return mevt;
+ }
+
+ return NULL;
+}
+
+static int rdtgroup_modify_assign_state(char *assign, struct rdt_mon_domain *d,
+ struct rdtgroup *rdtgrp, struct mon_evt *mevt)
+{
+ int ret = 0;
+
+ if (!assign || strlen(assign) != 1)
+ return -EINVAL;
+
+ switch (*assign) {
+ case 'e':
+ ret = rdtgroup_assign_cntr_event(d, rdtgrp, mevt);
+ break;
+ case '_':
+ rdtgroup_unassign_cntr_event(d, rdtgrp, mevt);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ return ret;
+}
+
+static int resctrl_parse_mbm_assignment(struct rdt_resource *r, struct rdtgroup *rdtgrp,
+ char *event, char *tok)
+{
+ struct rdt_mon_domain *d;
+ unsigned long dom_id = 0;
+ char *dom_str, *id_str;
+ struct mon_evt *mevt;
+ int ret;
+
+ mevt = mbm_get_mon_event_by_name(r, event);
+ if (!mevt) {
+ rdt_last_cmd_printf("Invalid event %s\n", event);
+ return -ENOENT;
+ }
+
+next:
+ if (!tok || tok[0] == '\0')
+ return 0;
+
+ /* Start processing the strings for each domain */
+ dom_str = strim(strsep(&tok, ";"));
+
+ id_str = strsep(&dom_str, "=");
+
+ /* Check for domain id '*' which means all domains */
+ if (id_str && *id_str == '*') {
+ ret = rdtgroup_modify_assign_state(dom_str, NULL, rdtgrp, mevt);
+ if (ret)
+ rdt_last_cmd_printf("Assign operation '%s:*=%s' failed\n",
+ event, dom_str);
+ return ret;
+ } else if (!id_str || kstrtoul(id_str, 10, &dom_id)) {
+ rdt_last_cmd_puts("Missing domain id\n");
+ return -EINVAL;
+ }
+
+ /* Verify if the dom_id is valid */
+ list_for_each_entry(d, &r->mon_domains, hdr.list) {
+ if (d->hdr.id == dom_id) {
+ ret = rdtgroup_modify_assign_state(dom_str, d, rdtgrp, mevt);
+ if (ret) {
+ rdt_last_cmd_printf("Assign operation '%s:%ld=%s' failed\n",
+ event, dom_id, dom_str);
+ return ret;
+ }
+ goto next;
+ }
+ }
+
+ rdt_last_cmd_printf("Invalid domain id %ld\n", dom_id);
+ return -EINVAL;
+}
+
+ssize_t mbm_L3_assignments_write(struct kernfs_open_file *of, char *buf,
+ size_t nbytes, loff_t off)
+{
+ struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
+ struct rdtgroup *rdtgrp;
+ char *token, *event;
+ int ret = 0;
+
+ /* Valid input requires a trailing newline */
+ if (nbytes == 0 || buf[nbytes - 1] != '\n')
+ return -EINVAL;
+
+ buf[nbytes - 1] = '\0';
+
+ rdtgrp = rdtgroup_kn_lock_live(of->kn);
+ if (!rdtgrp) {
+ rdtgroup_kn_unlock(of->kn);
+ return -ENOENT;
+ }
+ rdt_last_cmd_clear();
+
+ if (!resctrl_arch_mbm_cntr_assign_enabled(r)) {
+ rdt_last_cmd_puts("mbm_event mode is not enabled\n");
+ rdtgroup_kn_unlock(of->kn);
+ return -EINVAL;
+ }
+
+ while ((token = strsep(&buf, "\n")) != NULL) {
+ /*
+ * The write command follows the following format:
+ * "<Event>:<Domain ID>=<Assignment state>"
+ * Extract the event name first.
+ */
+ event = strsep(&token, ":");
+
+ ret = resctrl_parse_mbm_assignment(r, rdtgrp, event, token);
+ if (ret)
+ break;
+ }
+
+ rdtgroup_kn_unlock(of->kn);
+
+ return ret ?: nbytes;
+}
+
/**
* resctrl_mon_resource_init() - Initialise global monitoring structures.
*
projects / thirdparty / kernel / stable.git / commitdiff
