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.
>
> 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"
> + 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.
> "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[]).
> + 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()?
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.
> +{
> + 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?
> +
> + 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.
> + 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
