[PATCH v7 15/49] x86/resctrl: Move monitor exit work to a resctrl exit call

James Morse
2025-02-28T20:00:53Z

rdt_put_mon_l3_config() is called via the architecture's
resctrl_arch_exit() call, and appears to free the rmid_ptrs[]
and closid_num_dirty_rmid[] arrays. In reality this code is marked
__exit, and is removed by the linker as resctrl can't be built
as a module.

To separate the filesystem and architecture parts of resctrl,
this free()ing work needs to be triggered by the filesystem,
as these structures belong to the filesystem code.

Rename rdt_put_mon_l3_config() resctrl_mon_resource_exit()
and call it from resctrl_exit(). The kfree() is currently
dependent on r->mon_capable.

Signed-off-by: James Morse <james.morse@arm.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
---
Changes since v4:
* Added __exit so it can be removed in the next patch.

Changes since v3:
* Moved r->mon_capable check under the lock.
* Dropped references to resctrl_mon_resource_init() from the commit message.
* Fixed more resctrl typos,

Changes since v2:
* Dropped __exit as needed in the next patch.

Change since v1:
* [Commit message only] Typo fixes:
s/restrl/resctrl/g
s/resctl/resctrl/g

* [Commit message only] Reword second paragraph to remove reference to
the MPAM error interrupt, which provides background rationale for a
later patch rather than for this patch, and so it is not really
relevant here.
---
arch/x86/kernel/cpu/resctrl/core.c | 5 -----
arch/x86/kernel/cpu/resctrl/internal.h | 2 +-
arch/x86/kernel/cpu/resctrl/monitor.c | 12 +++++++++---
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 2 ++
4 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 26ae43659c6c..d04d65754491 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -1076,14 +1076,9 @@ late_initcall(resctrl_arch_late_init);

static void __exit resctrl_arch_exit(void)
{
- struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
-
cpuhp_remove_state(rdt_online);

resctrl_exit();
-
- if (r->mon_capable)
- rdt_put_mon_l3_config();
}

__exitcall(resctrl_arch_exit);
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 5f3713fb2eaf..73005ca2dda1 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -586,7 +586,7 @@ void closid_free(int closid);
int alloc_rmid(u32 closid);
void free_rmid(u32 closid, u32 rmid);
int rdt_get_mon_l3_config(struct rdt_resource *r);
-void __exit rdt_put_mon_l3_config(void);
+void __exit resctrl_mon_resource_exit(void);
bool __init rdt_cpu_has(int flag);
void mon_event_count(void *info);
int rdtgroup_mondata_show(struct seq_file *m, void *arg);
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index e8388d19a579..15e8c0190bfc 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -1040,10 +1040,13 @@ static int dom_data_init(struct rdt_resource *r)
return err;
}

-static void __exit dom_data_exit(void)
+static void __exit dom_data_exit(struct rdt_resource *r)
{
mutex_lock(&rdtgroup_mutex);

+ if (!r->mon_capable)
+ goto out_unlock;
+
if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) {
kfree(closid_num_dirty_rmid);
closid_num_dirty_rmid = NULL;
@@ -1052,6 +1055,7 @@ static void __exit dom_data_exit(void)
kfree(rmid_ptrs);
rmid_ptrs = NULL;

+out_unlock:
mutex_unlock(&rdtgroup_mutex);
}

@@ -1237,9 +1241,11 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
return 0;
}

-void __exit rdt_put_mon_l3_config(void)
+void __exit resctrl_mon_resource_exit(void)
{
- dom_data_exit();
+ struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
+
+ dom_data_exit(r);
}

void __init intel_rdt_mbm_apply_quirk(void)
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 9eb57ebb36c6..42c48e79364d 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -4296,4 +4296,6 @@ void __exit resctrl_exit(void)
debugfs_remove_recursive(debugfs_resctrl);
unregister_filesystem(&rdt_fs_type);
sysfs_remove_mount_point(fs_kobj, "resctrl");
+
+ resctrl_mon_resource_exit();
}
--
2.39.5