Hi Reinette, On 7/17/25 23:01, Reinette Chatre wrote: > Hi Babu, > > On 7/8/25 3:17 PM, Babu Moger wrote: >> Enable the mbm_l3_assignments resctrl file to be used to modify counter >> assignments of CTRL_MON and MON groups when the "mbm_event" counter >> assignment mode is enabled. >> >> The assignment modifications are done in the following format: >> <Event>:<Domain id>=<Assignment state> >> >> Event: A valid MBM event in the >> /sys/fs/resctrl/info/L3_MON/event_configs directory. >> >> Domain ID: A valid domain ID. When writing, '*' applies the changes >> to all domains. >> >> Assignment states: >> >> _ : Unassign the counter. > > "the counter" -> "a counter" (user cannot control which counter is assigned) Sure. > >> >> e : Assign the counter exclusively. > > "the counter" -> "a counter" Sure. > >> >> Examples: >> >> $ cd /sys/fs/resctrl >> $ cat /sys/fs/resctrl/mbm_L3_assignments >> mbm_total_bytes:0=e;1=e >> mbm_local_bytes:0=e;1=e >> >> To unassign the counter associated with the mbm_total_bytes event on >> domain 0: >> >> $ echo "mbm_total_bytes:0=_" > 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:*=_" > mbm_L3_assignments >> $ cat /sys/fs/resctrl/mbm_L3_assignments >> mbm_total_bytes:0=_;1=_ >> mbm_local_bytes:0=e;1=e >> >> Signed-off-by: Babu Moger <babu.moger@xxxxxxx> >> --- > > ... > >> --- >> Documentation/filesystems/resctrl.rst | 146 +++++++++++++++++++++++++- >> fs/resctrl/internal.h | 2 + >> fs/resctrl/monitor.c | 18 ++++ >> fs/resctrl/rdtgroup.c | 123 +++++++++++++++++++++- >> 4 files changed, 287 insertions(+), 2 deletions(-) >> >> diff --git a/Documentation/filesystems/resctrl.rst b/Documentation/filesystems/resctrl.rst >> index 4dd1d605d6ad..2b2acb55d8b1 100644 >> --- a/Documentation/filesystems/resctrl.rst >> +++ b/Documentation/filesystems/resctrl.rst >> @@ -527,7 +527,8 @@ When the "mba_MBps" mount option is used all CTRL_MON groups will also contain: >> 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: >> >> @@ -544,6 +545,34 @@ When the "mba_MBps" mount option is used all CTRL_MON groups will also contain: >> mbm_total_bytes:0=e;1=e >> mbm_local_bytes:0=e;1=e >> >> + Assignments can be modified by writing to the interface. >> + >> + Example: >> + 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 the counter associated with the mbm_total_bytes event on all domains in > > "the counter" -> "a counter" (motivation: user space cannot control which counter is assigned) Sure. > >> + 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 >> + >> Resource allocation rules >> ------------------------- >> >> @@ -1579,6 +1608,121 @@ View the llc occupancy snapshot:: >> # 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/ > > "#mount" -> "# mount" (please build htmldocs to confirm everything > looks consistent) Sure. > >> + >> + # 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: > > Please note that these steps are inconsistent. Some end with "." and some end with ":" Fixed it. > >> +:: >> + >> + # 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 > > ah ... here "a counter" is used. > >> +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. If the event is unassigned when >> +reading, then the read will come back as "Unassigned". > > Since returning "Unassigned" can be complicated, the associated description should > probably just be done once in the doc. I expect this will be in the "mon_data" section. Addressed with https://lore.kernel.org/lkml/2c107793-1258-4276-8b29-03359fa605f2@xxxxxxx/ > >> +:: >> + >> + # cat /sys/fs/resctrl/mon_data/mon_L3_00/mbm_total_bytes >> + 779247936 >> + # cat /sys/fs/resctrl/mon_data/mon_L3_00/mbm_local_bytes >> + 765207488 >> + >> +i. Check the default event configurations. > > Drop "default" (there are only these event configurations) > Sure. >> +:: >> + >> + # 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/counter_configs/mbm_local_bytes/event_filter > > "counter_configs" -> "event_configs" (this was also an issue in previous series, please > use grep to ensure all are fixed) Fixed. > >> + >> + # cat /sys/fs/resctrl/info/L3_MON/counter_configs/mbm_local_bytes/event_filter > > "counter_configs" -> "event_configs" > Sure. >> + local_reads,local_non_temporal_writes,local_reads_slow_memory,remote_reads >> + >> +This will update all (across all domains of all monitor groups) counter assignments >> +associated with the mbm_local_bytes event. >> + >> +k. Now read the local event 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 >> + 314101 >> + >> +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 > > "Unmount the resctrl" -> "Unmount resctrl" or "Unmount the resctrl filesystem"? Changed to "Unmount the resctrl filesystem." > >> +:: >> + >> + #umount /sys/fs/resctrl/ > > "#umount" -> "# umount" > Sure. >> + >> Intel RDT Errata >> ================ >> >> diff --git a/fs/resctrl/internal.h b/fs/resctrl/internal.h >> index b42890fd937a..9881674909f2 100644 >> --- a/fs/resctrl/internal.h >> +++ b/fs/resctrl/internal.h >> @@ -403,6 +403,8 @@ bool closid_allocated(unsigned int closid); >> >> int resctrl_find_cleanest_closid(void); >> >> +struct mon_evt *mbm_get_mon_event_by_name(struct rdt_resource *r, char *name); >> + >> int rdtgroup_assign_cntr_event(struct rdt_mon_domain *d, struct rdtgroup *rdtgrp, >> struct mon_evt *mevt); >> void rdtgroup_unassign_cntr_event(struct rdt_mon_domain *d, struct rdtgroup *rdtgrp, >> diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c >> index e30a867c00bb..61419849b257 100644 >> --- a/fs/resctrl/monitor.c >> +++ b/fs/resctrl/monitor.c >> @@ -1220,3 +1220,21 @@ void resctrl_update_cntr_allrdtgrp(struct mon_evt *mevt) >> rdtgroup_update_cntr_event(r, crgrp, mevt->evtid); >> } >> } >> + >> +/* >> + * mbm_get_mon_event_by_name() - Return the mon_evt entry for the matching >> + * event name. >> + */ >> +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; >> +} >> diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c >> index dc108c5db298..b26baca389bb 100644 >> --- a/fs/resctrl/rdtgroup.c >> +++ b/fs/resctrl/rdtgroup.c >> @@ -2071,6 +2071,126 @@ static int mbm_L3_assignments_show(struct kernfs_open_file *of, struct seq_file >> return ret; >> } >> >> +static int rdtgroup_modify_assign_state(char *assign, struct rdt_mon_domain *d, > > Please move to monitor.c Sure. > >> + 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); > > This patch enables the user to assign counters to multiple events in a > single write. Looking at this flow: > rdtgroup_assign_cntr_event()->rdtgroup_alloc_config_cntr() may thus > be called on the same domain but for different events in a single write from > user space. > I thus think that the error message in rdtgroup_alloc_config_cntr() > should not just contain the domain ID, but also the event *name* > (not the ID since user space cannot be expect to understand if). > considering this it seems that @mevt can be passed through > to rdtgroup_alloc_config_cntr() instead of just the event ID to support > this? Yes. Taken care. > >> + break; >> + case '_': >> + rdtgroup_unassign_cntr_event(d, rdtgrp, mevt); >> + break; >> + default: >> + ret = -EINVAL; > > Please add a "break". > Sure. >> + } >> + >> + return ret; >> +} >> + >> +static int resctrl_process_assign(struct rdt_resource *r, struct rdtgroup *rdtgrp, > > Please move to monitor.c and rename to be more specific. For example, > resctrl_parse_mbm_assignment()? Open to ideas. Sure. Fine with resctrl_parse_mbm_assignment(). > >> + 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; >> +} >> + > Reinette > -- Thanks Babu Moger
