[PATCH v3 21/26] fs-x86/resctrl: Handle RDT_RESOURCE_PERF_PKG in domain create/delete

Tony Luck
2025-04-07T23:41:01Z

Add a new rdt_perf_pkg_mon_domain structure. This only consists of
the common rdt_domain_hdr as there is no need for any per-domain
data structures.

Use as much as possible of the existing domain setup and tear down
infrastructure. In many cases the RDT_RESOURCE_PERF_PKG uses the
same functions but just skips over the pieces it does not need.

Signed-off-by: Tony Luck <tony.luck@intel.com>
---
include/linux/resctrl.h | 8 ++++++++
arch/x86/kernel/cpu/resctrl/core.c | 32 ++++++++++++++++++++++++++++++
fs/resctrl/rdtgroup.c | 11 ++++++++--
3 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index c03e7dc1f009..6f598a64b192 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -169,6 +169,14 @@ struct rdt_mon_domain {
int cqm_work_cpu;
};

+/**
+ * struct rdt_perf_pkg_mon_domain - CPUs sharing an Intel-PMT-scoped resctrl monitor resource
+ * @hdr: common header for different domain types
+ */
+struct rdt_perf_pkg_mon_domain {
+ struct rdt_domain_hdr hdr;
+};
+
/**
* struct resctrl_cache - Cache allocation related data
* @cbm_len: Length of the cache bit mask
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 9578d9c7260c..6f5d52a8219b 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -542,6 +542,29 @@ static void setup_l3_mon_domain(int cpu, int id, struct rdt_resource *r, struct
}
}

+static void setup_intel_aet_mon_domain(int cpu, int id, struct rdt_resource *r,
+ struct list_head *add_pos)
+{
+ struct rdt_perf_pkg_mon_domain *d;
+ int err;
+
+ d = kzalloc_node(sizeof(*d), GFP_KERNEL, cpu_to_node(cpu));
+ if (!d)
+ return;
+
+ d->hdr.id = id;
+ d->hdr.type = DOMTYPE(r->rid, DOMTYPE_MON);
+ cpumask_set_cpu(cpu, &d->hdr.cpu_mask);
+ list_add_tail_rcu(&d->hdr.list, add_pos);
+
+ err = resctrl_online_mon_domain(r, &d->hdr);
+ if (err) {
+ list_del_rcu(&d->hdr.list);
+ synchronize_rcu();
+ kfree(d);
+ }
+}
+
static void domain_add_cpu_mon(int cpu, struct rdt_resource *r)
{
int id = get_domain_id_from_scope(cpu, r->mon_scope);
@@ -571,6 +594,9 @@ static void domain_add_cpu_mon(int cpu, struct rdt_resource *r)
case RDT_RESOURCE_L3:
setup_l3_mon_domain(cpu, id, r, add_pos);
break;
+ case RDT_RESOURCE_PERF_PKG:
+ setup_intel_aet_mon_domain(cpu, id, r, add_pos);
+ break;
default:
WARN_ON_ONCE(1);
}
@@ -668,6 +694,12 @@ static void domain_remove_cpu_mon(int cpu, struct rdt_resource *r)
synchronize_rcu();
mon_domain_free(hw_dom);
break;
+ case RDT_RESOURCE_PERF_PKG:
+ resctrl_offline_mon_domain(r, d);
+ list_del_rcu(&hdr->list);
+ synchronize_rcu();
+ kfree(container_of(hdr, struct rdt_perf_pkg_mon_domain, hdr));
+ break;
}
}

diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
index 5ca6de6a6e5c..34fcd20f8dd7 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -4020,6 +4020,9 @@ void resctrl_offline_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d
if (resctrl_mounted && resctrl_arch_mon_capable())
rmdir_mondata_subdir_allrdtgrp(r, &d->hdr);

+ if (r->rid == RDT_RESOURCE_PERF_PKG)
+ goto done;
+
if (resctrl_is_mbm_enabled())
cancel_delayed_work(&d->mbm_over);
if (resctrl_arch_is_llc_occupancy_enabled() && has_busy_rmid(d)) {
@@ -4036,7 +4039,7 @@ void resctrl_offline_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d
}

domain_destroy_mon_state(d);
-
+done:
mutex_unlock(&rdtgroup_mutex);
}

@@ -4104,12 +4107,15 @@ int resctrl_online_ctrl_domain(struct rdt_resource *r, struct rdt_ctrl_domain *d
int resctrl_online_mon_domain(struct rdt_resource *r, struct rdt_domain_hdr *hdr)
{
struct rdt_mon_domain *d;
- int err;
+ int err = 0;

WARN_ON_ONCE(hdr->type != DOMTYPE(r->rid, DOMTYPE_MON));
d = container_of(hdr, struct rdt_mon_domain, hdr);
mutex_lock(&rdtgroup_mutex);

+ if (r->rid == RDT_RESOURCE_PERF_PKG)
+ goto do_mkdir;
+
err = domain_setup_mon_state(r, d);
if (err)
goto out_unlock;
@@ -4123,6 +4129,7 @@ int resctrl_online_mon_domain(struct rdt_resource *r, struct rdt_domain_hdr *hdr
if (resctrl_arch_is_llc_occupancy_enabled())
INIT_DELAYED_WORK(&d->cqm_limbo, cqm_handle_limbo);

+do_mkdir:
/*
* If the filesystem is not mounted then only the default resource group
* exists. Creation of its directories is deferred until mount time
--
2.48.1