In x86, hardware uses RMID to identify a monitoring group. When a user creates a monitor group these details are not visible. These details can help resctrl debugging. Add RMID(mon_hw_id) to the monitor groups display in resctrl interface. Users can see these details when resctrl is mounted with "-o debug" option. Add RFTYPE_MON_BASE complements existing RFTYPE_CTRL_BASE and represents files belonging to monitoring groups. Other architectures do not use "RMID". Use the name mon_hw_id to refer to "RMID" in an effort to keep the naming generic. For example: $cat /sys/fs/resctrl/mon_groups/mon_grp1/mon_hw_id 3 Signed-off-by: Babu Moger <babu.moger@xxxxxxx> Tested-by: Peter Newman <peternewman@xxxxxxxxxx> Reviewed-by: Peter Newman <peternewman@xxxxxxxxxx> Tested-by: Tan Shaopeng <tan.shaopeng@xxxxxxxxxxxxxx> Reviewed-by: Tan Shaopeng <tan.shaopeng@xxxxxxxxxxxxxx> Reviewed-by: Fenghua Yu <fenghua.yu@xxxxxxxxx> Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> --- v12: Moved the comments from arch/x86/kernel/cpu/resctrl/internal.h to Documentation/arch/x86/resctrl.rst. (Boris) Moved RFTYPE_MON_BASE definition here where it is being used. (Boris) --- Documentation/arch/x86/resctrl.rst | 9 +++++++++ arch/x86/kernel/cpu/resctrl/internal.h | 1 + arch/x86/kernel/cpu/resctrl/rdtgroup.c | 23 +++++++++++++++++++++++ 3 files changed, 33 insertions(+) diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst index 5dcd7d250ca8..e89b889980ae 100644 --- a/Documentation/arch/x86/resctrl.rst +++ b/Documentation/arch/x86/resctrl.rst @@ -369,6 +369,10 @@ When monitoring is enabled all MON groups will also contain: the sum for all tasks in the CTRL_MON group and all tasks in MON groups. Please see example section for more details on usage. +"mon_hw_id": + Available only with debug option. The identifier used by hardware + for the monitor group. On x86 this is the RMID. + RESCTRL filesystem implementation notes ======================================= RESCTRL filesystem has two main components @@ -426,6 +430,11 @@ RESCTRL filesystem has two main components --> RFTYPE_BASE (Files common for both MON and CTRL groups) Files: cpus, cpus_list, tasks + --> RFTYPE_MON (Files for MON group) + + --> RFTYPE_DEBUG (Files to help resctrl debugging) + File: mon_hw_id + --> RFTYPE_CTRL (Files for CTRL group) Files: mode, schemata, size diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index f0d135e004e2..714606275b98 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -254,6 +254,7 @@ struct rdtgroup { #define RFTYPE_MON_INFO (RFTYPE_INFO | RFTYPE_MON) #define RFTYPE_TOP_INFO (RFTYPE_INFO | RFTYPE_TOP) #define RFTYPE_CTRL_BASE (RFTYPE_BASE | RFTYPE_CTRL) +#define RFTYPE_MON_BASE (RFTYPE_BASE | RFTYPE_MON) /* List of all resource groups */ extern struct list_head rdt_all_groups; diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 55d1b90f460e..ef4b18091e5d 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -795,6 +795,22 @@ static int rdtgroup_closid_show(struct kernfs_open_file *of, return ret; } +static int rdtgroup_rmid_show(struct kernfs_open_file *of, + struct seq_file *s, void *v) +{ + struct rdtgroup *rdtgrp; + int ret = 0; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (rdtgrp) + seq_printf(s, "%u\n", rdtgrp->mon.rmid); + else + ret = -ENOENT; + rdtgroup_kn_unlock(of->kn); + + return ret; +} + #ifdef CONFIG_PROC_CPU_RESCTRL /* @@ -1856,6 +1872,13 @@ static struct rftype res_common_files[] = { .seq_show = rdtgroup_tasks_show, .fflags = RFTYPE_BASE, }, + { + .name = "mon_hw_id", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = rdtgroup_rmid_show, + .fflags = RFTYPE_MON_BASE | RFTYPE_DEBUG, + }, { .name = "schemata", .mode = 0644, -- 2.34.1