Hi Babu, On 5/15/25 3:52 PM, Babu Moger wrote: > 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 "assign counter IDs" -> "assign counter IDs to <what?>" > 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 assign the monitoring counters to what? > + 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 Please be explicit in docs what possible values are and what they mean. > + > "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); > } > Needs to be squashed. > @@ -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(); not traversing the domain list so hotplug lock not needed. > + mutex_lock(&rdtgroup_mutex); rdtgroup_mutex seems only needed because the message buffer is cleared below, and this is why it is not required in the show()? > + 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? How is "monitor assignment" different from "counter assignment"? > * @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; > }; > Reinette
