From cba8222880b88d96f3ed6c8a115e335e552b83a1 Mon Sep 17 00:00:00 2001 From: Babu Moger Date: Fri, 5 Sep 2025 16:34:27 -0500 Subject: [PATCH] fs/resctrl: Introduce mbm_L3_assignments to list assignments in a group 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 --- Documentation/filesystems/resctrl.rst | 31 +++++++++++++++++ fs/resctrl/internal.h | 2 ++ fs/resctrl/monitor.c | 49 +++++++++++++++++++++++++++ fs/resctrl/rdtgroup.c | 6 ++++ 4 files changed, 88 insertions(+) diff --git a/Documentation/filesystems/resctrl.rst b/Documentation/filesystems/resctrl.rst index 1de815b3a07b4..a2b7240b0818b 100644 --- a/Documentation/filesystems/resctrl.rst +++ b/Documentation/filesystems/resctrl.rst @@ -509,6 +509,37 @@ When monitoring is enabled all MON groups will also contain: Available only with debug option. The identifier used by hardware for the monitor group. On x86 this is the RMID. +When monitoring is enabled all MON groups may also contain: + +"mbm_L3_assignments": + Exists when "mbm_event" counter assignment mode is supported and lists the + counter assignment states of the group. + + The assignment list is displayed 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. + + Assignment states: + + _ : No counter assigned. + + e : Counter assigned exclusively. + + Example: + + To display the counter 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 + When the "mba_MBps" mount option is used all CTRL_MON groups will also contain: "mba_MBps_event": diff --git a/fs/resctrl/internal.h b/fs/resctrl/internal.h index 66c677c1b8588..43297b36f5dda 100644 --- a/fs/resctrl/internal.h +++ b/fs/resctrl/internal.h @@ -416,6 +416,8 @@ int resctrl_mbm_assign_on_mkdir_show(struct kernfs_open_file *of, ssize_t resctrl_mbm_assign_on_mkdir_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off); +int mbm_L3_assignments_show(struct kernfs_open_file *of, struct seq_file *s, void *v); + #ifdef CONFIG_RESCTRL_FS_PSEUDO_LOCK int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp); diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c index 9cb334136d210..b692a0ef17107 100644 --- a/fs/resctrl/monitor.c +++ b/fs/resctrl/monitor.c @@ -1454,6 +1454,54 @@ out_unlock: return ret; } +int mbm_L3_assignments_show(struct kernfs_open_file *of, struct seq_file *s, void *v) +{ + struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3); + struct rdt_mon_domain *d; + struct rdtgroup *rdtgrp; + struct mon_evt *mevt; + int ret = 0; + bool sep; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!rdtgrp) { + ret = -ENOENT; + goto out_unlock; + } + + rdt_last_cmd_clear(); + if (!resctrl_arch_mbm_cntr_assign_enabled(r)) { + rdt_last_cmd_puts("mbm_event counter assignment mode is not enabled\n"); + ret = -EINVAL; + goto out_unlock; + } + + for_each_mon_event(mevt) { + if (mevt->rid != r->rid || !mevt->enabled || !resctrl_is_mbm_event(mevt->evtid)) + continue; + + sep = false; + seq_printf(s, "%s:", mevt->name); + list_for_each_entry(d, &r->mon_domains, hdr.list) { + if (sep) + seq_putc(s, ';'); + + if (mbm_cntr_get(r, d, rdtgrp, mevt->evtid) < 0) + seq_printf(s, "%d=_", d->hdr.id); + else + seq_printf(s, "%d=e", d->hdr.id); + + sep = true; + } + seq_putc(s, '\n'); + } + +out_unlock: + rdtgroup_kn_unlock(of->kn); + + return ret; +} + /** * resctrl_mon_resource_init() - Initialise global monitoring structures. * @@ -1512,6 +1560,7 @@ int resctrl_mon_resource_init(void) resctrl_file_fflags_init("event_filter", RFTYPE_ASSIGN_CONFIG); resctrl_file_fflags_init("mbm_assign_on_mkdir", RFTYPE_MON_INFO | RFTYPE_RES_CACHE); + resctrl_file_fflags_init("mbm_L3_assignments", RFTYPE_MON_BASE); } return 0; diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c index 48f98146c0996..519aa6acef5b2 100644 --- a/fs/resctrl/rdtgroup.c +++ b/fs/resctrl/rdtgroup.c @@ -1937,6 +1937,12 @@ static struct rftype res_common_files[] = { .seq_show = event_filter_show, .write = event_filter_write, }, + { + .name = "mbm_L3_assignments", + .mode = 0444, + .kf_ops = &rdtgroup_kf_single_ops, + .seq_show = mbm_L3_assignments_show, + }, { .name = "mbm_assign_mode", .mode = 0444, -- 2.47.3