Hi Reinette,
On 6/25/25 18:23, Reinette Chatre wrote:
> Hi Babu,
>
> On 6/13/25 2:05 PM, Babu Moger wrote:
>> When assignable counters are supported the
>> /sys/fs/resctrl/info/L3_MON/event_configs directory contains a
>> sub-directory for each MBM event that can be assigned to a counter.
>> The MBM event sub-directory contains a file named "event_filter" that
>> is used to view and modify which memory transactions the MBM event is
>> configured with.
>>
>> Create the /sys/fs/resctrl/info/L3_MON/event_configs directory on resctrl
>> mount and pre-populate it with directories for the two existing MBM events:
>> mbm_total_bytes and mbm_local_bytes. Create the "event_filter" file within
>> each MBM event directory with the needed *show() that displays the memory
>> transactions with which the MBM event is configured.
>>
>> Example:
>> $ mount -t resctrl resctrl /sys/fs/resctrl
>> $ cd /sys/fs/resctrl/
>> $ cat 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 info/L3_MON/event_configs/mbm_local_bytes/event_filter
>> local_reads, local_non_temporal_writes, local_reads_slow_memory
>
> Please let these examples match what the patch does wrt spacing.
Sure.
>
>>
>> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
>> ---
>
> ...
>
>> ---
>> Documentation/filesystems/resctrl.rst | 32 +++++++++++
>> fs/resctrl/internal.h | 2 +
>> fs/resctrl/monitor.c | 1 +
>> fs/resctrl/rdtgroup.c | 78 +++++++++++++++++++++++++++
>> 4 files changed, 113 insertions(+)
>>
>> diff --git a/Documentation/filesystems/resctrl.rst b/Documentation/filesystems/resctrl.rst
>> index 18de335e1ff8..b1db1a53db2a 100644
>> --- a/Documentation/filesystems/resctrl.rst
>> +++ b/Documentation/filesystems/resctrl.rst
>> @@ -310,6 +310,38 @@ with the following files:
>> # cat /sys/fs/resctrl/info/L3_MON/available_mbm_cntrs
>> 0=30;1=30
>>
>> +"event_configs":
>> + Directory that exists when "mbm_event" mode is supported. Contains
>
> ""mbm_event" mode" -> ""mbm_event" counter assignment mode"
Sure.
>
>> + sub-directory for each MBM event that can be assigned to a counter.
>> +
>> + Two MBM events are supported by default: mbm_local_bytes and mbm_total_bytes.
>> + Each MBM event's sub-directory contains a file named "event_filter" that is
>> + used to view and modify which memory transactions the MBM event is configured
>> + with.
>> +
>> + List of memory transaction types supported:
>> +
>> + ========================== ========================================================
>> + Name Description
>> + ========================== ========================================================
>> + dirty_victim_writes_all Dirty Victims from the QOS domain to all types of memory
>> + remote_reads_slow_memory Reads to slow memory in the non-local NUMA domain
>> + local_reads_slow_memory Reads to slow memory in the local NUMA domain
>> + remote_non_temporal_writes Non-temporal writes to non-local NUMA domain
>> + local_non_temporal_writes Non-temporal writes to local NUMA domain
>> + remote_reads Reads to memory in the non-local NUMA domain
>> + local_reads Reads to memory in the local NUMA domain
>> + ========================== ========================================================
>> +
>> + For example::
>> +
>> + # 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
>> +
>
> Please let these examples match what the patch does wrt spacing.
Sure.
>
>> "max_threshold_occupancy":
>> Read/write file provides the largest value (in
>> bytes) at which a previously used LLC_occupancy
>> diff --git a/fs/resctrl/internal.h b/fs/resctrl/internal.h
>> index 84a136194d9a..ed0e3b695ad5 100644
>> --- a/fs/resctrl/internal.h
>> +++ b/fs/resctrl/internal.h
>> @@ -248,6 +248,8 @@ struct mbm_config_value {
>>
>> #define RFTYPE_DEBUG BIT(10)
>>
>> +#define RFTYPE_ASSIGN_CONFIG BIT(11)
>> +
>> #define RFTYPE_CTRL_INFO (RFTYPE_INFO | RFTYPE_CTRL)
>>
>> #define RFTYPE_MON_INFO (RFTYPE_INFO | RFTYPE_MON)
>> diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c
>> index ef6ef58f180b..09a49029a800 100644
>> --- a/fs/resctrl/monitor.c
>> +++ b/fs/resctrl/monitor.c
>> @@ -956,6 +956,7 @@ int resctrl_mon_resource_init(void)
>> RFTYPE_MON_INFO | RFTYPE_RES_CACHE);
>> resctrl_file_fflags_init("available_mbm_cntrs",
>> RFTYPE_MON_INFO | RFTYPE_RES_CACHE);
>> + resctrl_file_fflags_init("event_filter", RFTYPE_ASSIGN_CONFIG);
>> }
>>
>> return 0;
>> diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
>> index 5fb6a9939e23..e2fa5e10c2dd 100644
>> --- a/fs/resctrl/rdtgroup.c
>> +++ b/fs/resctrl/rdtgroup.c
>> @@ -1909,6 +1909,25 @@ static int resctrl_available_mbm_cntrs_show(struct kernfs_open_file *of,
>> return ret;
>> }
>>
>> +static int event_filter_show(struct kernfs_open_file *of, struct seq_file *seq, void *v)
>> +{
>> + struct mon_evt *mevt = rdt_kn_parent_priv(of->kn);
>> + bool sep = false;
>> + int i;
>> +
>> + for (i = 0; i < NUM_MBM_EVT_VALUES; i++) {
>> + if (mevt->evt_cfg & mbm_config_values[i].val) {
>> + if (sep)
>> + seq_putc(seq, ',');
>> + seq_printf(seq, "%s", mbm_config_values[i].name);
>
> Taking a closer look I think we need to be more careful about how the
> code is organized. Ideally the monitoring related code and data should
> be located in fs/resctrl/monitor.c. Having event_filter_show() here is
> ok because of its use in res_common_files[]. Since it is monitoring related
> I expected its code/data to be in fs/resctrl/monitor.c, thus that
> mbm_config_values[] (mbm_transactions[]?) to be in fs/resctrl/monitor.c,
> (just like mon_event_all[]).
Sure. Moved mbm_transactions[] to monitor.c.
Defined it as extern in fs/resctrl/rdtgroup.c
extern struct mbm_transaction mbm_transactions[NUM_MBM_TRANSACTIONS];
>
>> + sep = true;
>> + }
>> + }
>> + seq_putc(seq, '\n');
>> +
>> + return 0;
>> +}
>> +
>> /* rdtgroup information files for one cache resource. */
>> static struct rftype res_common_files[] = {
>> {
>> @@ -2033,6 +2052,12 @@ 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,
>> @@ -2315,6 +2340,53 @@ static int rdtgroup_mkdir_info_resdir(void *priv, char *name,
>> return ret;
>> }
>>
>> +static int resctrl_mkdir_counter_configs(struct rdt_resource *r, char *name)
>
> This can now be named resctrl_mkdir_event_configs()?
Sure.
>
> Also, I cannot see where the struct rdt_resource parameter is used. It should not
> be removed though, as mentioned earlier it should be used to ensure
> to check the mon_evt::rid values so that only events associated with resource
> are considered.
Added the check.
mevt->rid != r->rid
>
>> +{
>> + struct kernfs_node *l3_mon_kn, *kn_subdir, *kn_subdir2;
>> + struct mon_evt *mevt;
>> + int ret;
>> +
>> + l3_mon_kn = kernfs_find_and_get(kn_info, name);
>> + if (!l3_mon_kn)
>> + return -ENOENT;
>
> Needing to figure out this kn does not seem necessary. Can it not be
> provided via parameter instead?
>
> For example, resctrl_mkdir_counter_configs() (rather resctrl_mkdir_event_configs())
> can be called from rdtgroup_mkdir_info_resdir(). I understand rdtgroup_mkdir_info_resdir()
> is also called for struct resctrl_schema parameter but I think the fflags can be used
> to make the right decision. Something like:
>
> rdtgroup_mkdir_info_resdir() {
> struct rdt_resource *r;
>
> ...
> if (fflags & RFTYPE_MON_INFO) {
> r = priv;
> if (r->mon.mbm_cntr_assignable) {
> ret = resctrl_mkdir_event_configs(kn_subdir, r);
> ...
> }
> }
> }
>
> What do you think?
We can do that. Need to test it. Hopefully its fine.
>
>> +
>> + kn_subdir = kernfs_create_dir(l3_mon_kn, "event_configs", l3_mon_kn->mode, NULL);
>> + 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 (mevt = &mon_event_all[0]; mevt < &mon_event_all[QOS_NUM_EVENTS]; mevt++) {
>
> Here is a spot where the for_each_mon_event() should be used.
Sure.
>
>> + if (!mevt->enabled || !resctrl_is_mbm_event(mevt->evtid))
>> + continue;
>> +
>> + kn_subdir2 = kernfs_create_dir(kn_subdir, mevt->name, kn_subdir->mode, mevt);
>> + if (IS_ERR(kn_subdir2)) {
>> + ret = PTR_ERR(kn_subdir2);
>> + goto out_config;
>> + }
>> +
>> + ret = rdtgroup_kn_set_ugid(kn_subdir2);
>> + if (ret)
>> + goto out_config;
>> +
>> + ret = rdtgroup_add_files(kn_subdir2, RFTYPE_ASSIGN_CONFIG);
>> + if (!ret)
>> + kernfs_activate(kn_subdir);
>> + }
>> +
>> +out_config:
>> + kernfs_put(l3_mon_kn);
>> +
>> + return ret;
>> +}
>> +
>> static unsigned long fflags_from_resource(struct rdt_resource *r)
>> {
>> switch (r->rid) {
>> @@ -2361,6 +2433,12 @@ 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_counter_configs(r, name);
>> + if (ret)
>> + goto out_destroy;
>> + }
>> }
>>
>> ret = rdtgroup_kn_set_ugid(kn_info);
>
>
> Reinette
>
--
Thanks
Babu Moger
