diff options
| author | Ben Horgan <ben.horgan@arm.com> | 2026-05-06 11:28:50 +0300 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2026-05-06 20:06:57 +0300 |
| commit | 94a1206522d11302ae7e7c28d3d494c8f0c9c58e (patch) | |
| tree | fea8dff67d9dcdc314dcb30216c706c94cb9adc8 /include/linux | |
| parent | 7625632fed431ddd655e839c302165536553f767 (diff) | |
| download | linux-94a1206522d11302ae7e7c28d3d494c8f0c9c58e.tar.xz | |
x86,fs/resctrl: Create 'event_filter' files read only if they're not configurable
When the counter assignment mode is mbm_event resctrl assumes the MBM
events are configurable and exposes the 'event_filter' files. These files
live at info/L3_MON/event_configs/<event>/event_filter and are used to
display and set the event configuration.
The MPAM architecture has support for configuring the memory bandwidth
utilization (MBWU) counters to only count reads or only count
writes. However, in MPAM, this event filtering support is optional in the
hardware (and not yet implemented in the MPAM driver) but MBM counter
assignment is always possible for MPAM MBWU counters.
In order to support mbm_event mode with MPAM, create the 'event_filter'
files read only if the event configuration can't be changed. A user can
still chmod the file and so also return early with an error from
event_filter_write().
Introduce a new monitor property, mbm_cntr_configurable, to indicate
whether or not assignable MBM counters are configurable. On x86, set this
to true whenever mbm_cntr_assignable is true to keep existing behaviour.
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/20260506082855.3694761-1-ben.horgan@arm.com
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/resctrl.h | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 006e57fd7ca5..06e8c72e8660 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -286,13 +286,14 @@ enum resctrl_schema_fmt { /** * struct resctrl_mon - Monitoring related data of a resctrl resource. - * @num_rmid: Number of RMIDs available. - * @mbm_cfg_mask: Memory transactions that can be tracked when bandwidth - * monitoring events can be configured. - * @num_mbm_cntrs: Number of assignable counters. - * @mbm_cntr_assignable:Is system capable of supporting counter assignment? - * @mbm_assign_on_mkdir:True if counters should automatically be assigned to MBM - * events of monitor groups created via mkdir. + * @num_rmid: Number of RMIDs available. + * @mbm_cfg_mask: Memory transactions that can be tracked when + * bandwidth monitoring events can be configured. + * @num_mbm_cntrs: Number of assignable counters. + * @mbm_cntr_assignable: Is system capable of supporting counter assignment? + * @mbm_assign_on_mkdir: True if counters should automatically be assigned to MBM + * events of monitor groups created via mkdir. + * @mbm_cntr_configurable: True if assignable counters are configurable. */ struct resctrl_mon { u32 num_rmid; @@ -300,6 +301,7 @@ struct resctrl_mon { int num_mbm_cntrs; bool mbm_cntr_assignable; bool mbm_assign_on_mkdir; + bool mbm_cntr_configurable; }; /** |