diff mbox series

[v7,6/8] x86/resctrl: Move default control group creation during mount

Message ID 169178463637.1147205.7411319721706077266.stgit@bmoger-ubuntu
State New
Headers
Series x86/resctrl: Miscellaneous resctrl features |

Commit Message

Moger, Babu Aug. 11, 2023, 8:10 p.m. UTC 
  The resctrl default control group is created during kernel init time.
If the new files are to be added to the default group based on the mount
option, then each file needs to be created separately and call
kernfs_activate() again.

This can be avoided if all the files are created during the mount and
destroyed during the umount. So, move the default group creation
in rdt_get_tree() and removal in rdt_kill_sb().

Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Babu Moger <babu.moger@amd.com>
---
 arch/x86/kernel/cpu/resctrl/internal.h |    1 +
 arch/x86/kernel/cpu/resctrl/rdtgroup.c |   50 +++++++++++++++++---------------
 2 files changed, 27 insertions(+), 24 deletions(-)

Comments

Reinette Chatre Aug. 16, 2023, 11:02 p.m. UTC | #1 
Hi Babu,

On 8/16/2023 12:14 PM, Moger, Babu wrote:
> Hi Reinette,
> 
> On 8/15/23 17:50, Reinette Chatre wrote:
>> Hi Babu,
>>
>> Please do note that the subject is no longer accurate.
> 
> Changing to
> 
> x86/resctrl: Move default group file creation during mount
> 

How about:
	x86/resctrl: Move default group file creation to mount

Reinette
diff mbox series

Patch

diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 37800724e002..2bd92c0c3b0c 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -602,5 +602,6 @@  void rdt_domain_reconfigure_cdp(struct rdt_resource *r);
 void __init thread_throttle_mode_init(void);
 void __init mbm_config_rftype_init(const char *config);
 void rdt_staged_configs_clear(void);
+int rdtgroup_setup_root(struct rdt_fs_context *ctx);
 
 #endif /* _ASM_X86_RESCTRL_INTERNAL_H */
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 0805fac04401..a7453c93bad4 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -2521,10 +2521,14 @@  static int rdt_get_tree(struct fs_context *fc)
 		goto out;
 	}
 
-	ret = rdt_enable_ctx(ctx);
+	ret = rdtgroup_setup_root(ctx);
 	if (ret)
 		goto out;
 
+	ret = rdt_enable_ctx(ctx);
+	if (ret)
+		goto out_root;
+
 	ret = schemata_list_create();
 	if (ret) {
 		schemata_list_destroy();
@@ -2533,6 +2537,12 @@  static int rdt_get_tree(struct fs_context *fc)
 
 	closid_init();
 
+	ret = rdtgroup_add_files(rdtgroup_default.kn, RFTYPE_CTRL_BASE);
+	if (ret)
+		goto out_schemata_free;
+
+	kernfs_activate(rdtgroup_default.kn);
+
 	ret = rdtgroup_create_info_dir(rdtgroup_default.kn);
 	if (ret < 0)
 		goto out_schemata_free;
@@ -2589,6 +2599,8 @@  static int rdt_get_tree(struct fs_context *fc)
 	schemata_list_destroy();
 out_ctx:
 	rdt_disable_ctx(ctx);
+out_root:
+	kernfs_destroy_root(rdt_root);
 out:
 	rdt_last_cmd_clear();
 	mutex_unlock(&rdtgroup_mutex);
@@ -2659,7 +2671,6 @@  static int rdt_init_fs_context(struct fs_context *fc)
 	if (!ctx)
 		return -ENOMEM;
 
-	ctx->kfc.root = rdt_root;
 	ctx->kfc.magic = RDTGROUP_SUPER_MAGIC;
 	fc->fs_private = &ctx->kfc;
 	fc->ops = &rdt_fs_context_ops;
@@ -2830,6 +2841,7 @@  static void rdt_kill_sb(struct super_block *sb)
 	rdt_pseudo_lock_release();
 	rdtgroup_default.mode = RDT_MODE_SHAREABLE;
 	schemata_list_destroy();
+	kernfs_destroy_root(rdt_root);
 	static_branch_disable_cpuslocked(&rdt_alloc_enable_key);
 	static_branch_disable_cpuslocked(&rdt_mon_enable_key);
 	static_branch_disable_cpuslocked(&rdt_enable_key);
@@ -3711,10 +3723,8 @@  static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = {
 	.show_options	= rdtgroup_show_options,
 };
 
-static int __init rdtgroup_setup_root(void)
+int rdtgroup_setup_root(struct rdt_fs_context *ctx)
 {
-	int ret;
-
 	rdt_root = kernfs_create_root(&rdtgroup_kf_syscall_ops,
 				      KERNFS_ROOT_CREATE_DEACTIVATED |
 				      KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK,
@@ -3722,6 +3732,15 @@  static int __init rdtgroup_setup_root(void)
 	if (IS_ERR(rdt_root))
 		return PTR_ERR(rdt_root);
 
+	ctx->kfc.root = rdt_root;
+
+	rdtgroup_default.kn = kernfs_root_to_node(rdt_root);
+
+	return 0;
+}
+
+static void __init rdtgroup_setup_default(void)
+{
 	mutex_lock(&rdtgroup_mutex);
 
 	rdtgroup_default.closid = 0;
@@ -3731,19 +3750,7 @@  static int __init rdtgroup_setup_root(void)
 
 	list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups);
 
-	ret = rdtgroup_add_files(kernfs_root_to_node(rdt_root), RFTYPE_CTRL_BASE);
-	if (ret) {
-		kernfs_destroy_root(rdt_root);
-		goto out;
-	}
-
-	rdtgroup_default.kn = kernfs_root_to_node(rdt_root);
-	kernfs_activate(rdtgroup_default.kn);
-
-out:
 	mutex_unlock(&rdtgroup_mutex);
-
-	return ret;
 }
 
 static void domain_destroy_mon_state(struct rdt_domain *d)
@@ -3865,13 +3872,11 @@  int __init rdtgroup_init(void)
 	seq_buf_init(&last_cmd_status, last_cmd_status_buf,
 		     sizeof(last_cmd_status_buf));
 
-	ret = rdtgroup_setup_root();
-	if (ret)
-		return ret;
+	rdtgroup_setup_default();
 
 	ret = sysfs_create_mount_point(fs_kobj, "resctrl");
 	if (ret)
-		goto cleanup_root;
+		return ret;
 
 	ret = register_filesystem(&rdt_fs_type);
 	if (ret)
@@ -3904,8 +3909,6 @@  int __init rdtgroup_init(void)
 
 cleanup_mountpoint:
 	sysfs_remove_mount_point(fs_kobj, "resctrl");
-cleanup_root:
-	kernfs_destroy_root(rdt_root);
 
 	return ret;
 }
@@ -3915,5 +3918,4 @@  void __exit rdtgroup_exit(void)
 	debugfs_remove_recursive(debugfs_resctrl);
 	unregister_filesystem(&rdt_fs_type);
 	sysfs_remove_mount_point(fs_kobj, "resctrl");
-	kernfs_destroy_root(rdt_root);
 }