kernel/linux.git/fs/resctrl/internal.h, branch v6.18.48

fs/resctrl: Move RMID initialization to first mount

2026-08-03T09:22:11+00:00

[ Upstream commit d0891647fbc6e931f27517364cbc4ee1811d76db ] L3 monitor features are enumerated during resctrl initialization and rmid_ptrs[] that tracks all RMIDs and depends on the number of supported RMIDs is allocated during this time. Telemetry monitor features are enumerated during first resctrl mount and may support a different number of RMIDs compared to L3 monitor features. Delay allocation and initialization of rmid_ptrs[] until first mount. Since the number of RMIDs cannot change on later mounts, keep the same set of rmid_ptrs[] until resctrl_exit(). This is required because the limbo handler keeps running after resctrl is unmounted and needs to access rmid_ptrs[] as it keeps tracking busy RMIDs after unmount. Rename routines to match what they now do: dom_data_init() -> setup_rmid_lru_list() dom_data_exit() -> free_rmid_lru_list() Signed-off-by: Tony Luck Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com Stable-dep-of: 52fce648607e ("fs/resctrl: Fix use-after-free during unmount") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

x86,fs/resctrl: Rename some L3 specific functions

2026-08-03T09:22:11+00:00

[ Upstream commit 9c214d10c50990c7a61b95887493df9ae713eec5 ] With the arrival of monitor events tied to new domains associated with a different resource it would be clearer if the L3 resource specific functions are more accurately named. Rename three groups of functions: Functions that allocate/free architecture per-RMID MBM state information: arch_domain_mbm_alloc() -> l3_mon_domain_mbm_alloc() mon_domain_free() -> l3_mon_domain_free() Functions that allocate/free filesystem per-RMID MBM state information: domain_setup_mon_state() -> domain_setup_l3_mon_state() domain_destroy_mon_state() -> domain_destroy_l3_mon_state() Initialization/exit: rdt_get_mon_l3_config() -> rdt_get_l3_mon_config() resctrl_mon_resource_init() -> resctrl_l3_mon_resource_init() resctrl_mon_resource_exit() -> resctrl_l3_mon_resource_exit() Ensure kernel-doc descriptions of these functions' return values are present and correctly formatted. Signed-off-by: Tony Luck Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com Stable-dep-of: 52fce648607e ("fs/resctrl: Fix use-after-free during unmount") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

x86,fs/resctrl: Rename struct rdt_mon_domain and rdt_hw_mon_domain

2026-08-03T09:22:11+00:00

[ Upstream commit 4bc3ef46ff41d5e7ba557e56e9cd2031527cd7f8 ] The upcoming telemetry event monitoring is not tied to the L3 resource and will have a new domain structure. Rename the L3 resource specific domain data structures to include "l3_" in their names to avoid confusion between the different resource specific domain structures: rdt_mon_domain -> rdt_l3_mon_domain rdt_hw_mon_domain -> rdt_hw_l3_mon_domain No functional change. Signed-off-by: Tony Luck Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Link: https://lore.kernel.org/20251217172121.12030-1-tony.luck@intel.com Stable-dep-of: 52fce648607e ("fs/resctrl: Fix use-after-free during unmount") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

fs/resctrl: Introduce the interface to switch between monitor modes

2025-09-15T10:49:18+00:00

Resctrl subsystem can support two monitoring modes, "mbm_event" or "default". In mbm_event mode, monitoring event can only accumulate data while it is backed by a hardware counter. In "default" mode, resctrl assumes there is a hardware counter for each event within every CTRL_MON and MON group. Introduce mbm_assign_mode resctrl file to switch between mbm_event and default modes. Example: To list the MBM monitor modes supported: $ cat /sys/fs/resctrl/info/L3_MON/mbm_assign_mode [mbm_event] default To enable the "mbm_event" counter assignment mode: $ echo "mbm_event" > /sys/fs/resctrl/info/L3_MON/mbm_assign_mode To enable the "default" monitoring mode: $ echo "default" > /sys/fs/resctrl/info/L3_MON/mbm_assign_mode Reset MBM event counters automatically as part of changing the mode. Clear both architectural and non-architectural event states to prevent overflow conditions during the next event read. Clear assignable counter configuration on all the domains. Also, enable auto assignment when switching to "mbm_event" mode. Signed-off-by: Babu Moger Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Link: https://lore.kernel.org/cover.1757108044.git.babu.moger@amd.com

fs/resctrl: Introduce the interface to modify assignments in a group

2025-09-15T10:47:17+00:00

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. Process the assignment modifications in the following format: :=;= 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 a counter. e : Assign a counter exclusively. 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 Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Link: https://lore.kernel.org/cover.1757108044.git.babu.moger@amd.com

fs/resctrl: Introduce mbm_L3_assignments to list assignments in a group

2025-09-15T10:45:34+00:00

Introduce the mbm_L3_assignments resctrl file associated with CTRL_MON and MON resource groups to display the counter assignment states of the resource group when "mbm_event" counter assignment mode is enabled. Display the list in the following format: :=;= Event: A valid MBM event listed in /sys/fs/resctrl/info/L3_MON/event_configs directory. Domain ID: A valid domain ID. The assignment state can be one of the following: _ : No counter assigned. e : Counter assigned exclusively. Example: To list the assignment states for the default group $ 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 Signed-off-by: Babu Moger Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Link: https://lore.kernel.org/cover.1757108044.git.babu.moger@amd.com

fs/resctrl: Introduce mbm_assign_on_mkdir to enable assignments on mkdir

2025-09-15T10:42:02+00:00

The "mbm_event" counter assignment mode allows users to assign a hardware counter to an RMID, event pair and monitor the bandwidth as long as it is assigned. Introduce a user-configurable option that determines if a counter will automatically be assigned to an RMID, event pair when its associated monitor group is created via mkdir. Accessible when "mbm_event" counter assignment mode is enabled. Suggested-by: Peter Newman Signed-off-by: Babu Moger Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Link: https://lore.kernel.org/cover.1757108044.git.babu.moger@amd.com

fs/resctrl: Provide interface to update the event configurations

2025-09-15T10:40:38+00:00

When "mbm_event" counter assignment mode is enabled, users can modify the event configuration by writing to the 'event_filter' resctrl file. The event configurations for mbm_event mode are located in /sys/fs/resctrl/info/L3_MON/event_configs/. Update the assignments of all CTRL_MON and MON resource groups when the event configuration is modified. Example: $ mount -t resctrl resctrl /sys/fs/resctrl $ cd /sys/fs/resctrl/ $ cat info/L3_MON/event_configs/mbm_local_bytes/event_filter local_reads,local_non_temporal_writes,local_reads_slow_memory $ echo "local_reads,local_non_temporal_writes" > info/L3_MON/event_configs/mbm_total_bytes/event_filter $ cat info/L3_MON/event_configs/mbm_total_bytes/event_filter local_reads,local_non_temporal_writes Signed-off-by: Babu Moger Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Link: https://lore.kernel.org/cover.1757108044.git.babu.moger@amd.com

fs/resctrl: Add event configuration directory under info/L3_MON/

2025-09-15T10:39:38+00:00

The "mbm_event" counter assignment mode allows the user to assign a hardware counter to an RMID, event pair and monitor the bandwidth as long as it is assigned. The user can specify the memory transaction(s) for the counter to track. When this mode is 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 /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 Signed-off-by: Babu Moger Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Link: https://lore.kernel.org/cover.1757108044.git.babu.moger@amd.com

fs/resctrl: Support counter read/reset with mbm_event assignment mode

2025-09-15T10:38:58+00:00

When "mbm_event" counter assignment mode is enabled, the architecture requires a counter ID to read the event data. Introduce an is_mbm_cntr field in struct rmid_read to indicate whether counter assignment mode is in use. Update the logic to call resctrl_arch_cntr_read() and resctrl_arch_reset_cntr() when the assignment mode is active. Report 'Unassigned' in case the user attempts to read an event without assigning a hardware counter. Suggested-by: Reinette Chatre Signed-off-by: Babu Moger Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Link: https://lore.kernel.org/cover.1757108044.git.babu.moger@amd.com