1 files changed, 67 insertions, 18 deletions

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 3f844f14fc0a..b494187632b2 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -592,6 +592,18 @@ static int __rdtgroup_move_task(struct task_struct *tsk,
 	return ret;
 }
 
+static bool is_closid_match(struct task_struct *t, struct rdtgroup *r)
+{
+	return (rdt_alloc_capable &&
+	       (r->type == RDTCTRL_GROUP) && (t->closid == r->closid));
+}
+
+static bool is_rmid_match(struct task_struct *t, struct rdtgroup *r)
+{
+	return (rdt_mon_capable &&
+	       (r->type == RDTMON_GROUP) && (t->rmid == r->mon.rmid));
+}
+
 /**
  * rdtgroup_tasks_assigned - Test if tasks have been assigned to resource group
  * @r: Resource group
@@ -607,8 +619,7 @@ int rdtgroup_tasks_assigned(struct rdtgroup *r)
 
 	rcu_read_lock();
 	for_each_process_thread(p, t) {
-		if ((r->type == RDTCTRL_GROUP && t->closid == r->closid) ||
-		    (r->type == RDTMON_GROUP && t->rmid == r->mon.rmid)) {
+		if (is_closid_match(t, r) || is_rmid_match(t, r)) {
 			ret = 1;
 			break;
 		}
@@ -706,8 +717,7 @@ static void show_rdt_tasks(struct rdtgroup *r, struct seq_file *s)
 
 	rcu_read_lock();
 	for_each_process_thread(p, t) {
-		if ((r->type == RDTCTRL_GROUP && t->closid == r->closid) ||
-		    (r->type == RDTMON_GROUP && t->rmid == r->mon.rmid))
+		if (is_closid_match(t, r) || is_rmid_match(t, r))
 			seq_printf(s, "%d\n", t->pid);
 	}
 	rcu_read_unlock();
@@ -1017,6 +1027,19 @@ static int max_threshold_occ_show(struct kernfs_open_file *of,
 	return 0;
 }
 
+static int rdt_thread_throttle_mode_show(struct kernfs_open_file *of,
+					 struct seq_file *seq, void *v)
+{
+	struct rdt_resource *r = of->kn->parent->priv;
+
+	if (r->membw.throttle_mode == THREAD_THROTTLE_PER_THREAD)
+		seq_puts(seq, "per-thread\n");
+	else
+		seq_puts(seq, "max\n");
+
+	return 0;
+}
+
 static ssize_t max_threshold_occ_write(struct kernfs_open_file *of,
 				       char *buf, size_t nbytes, loff_t off)
 {
@@ -1513,6 +1536,17 @@ static struct rftype res_common_files[] = {
 		.seq_show	= rdt_delay_linear_show,
 		.fflags		= RF_CTRL_INFO | RFTYPE_RES_MB,
 	},
+	/*
+	 * Platform specific which (if any) capabilities are provided by
+	 * thread_throttle_mode. Defer "fflags" initialization to platform
+	 * discovery.
+	 */
+	{
+		.name		= "thread_throttle_mode",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_thread_throttle_mode_show,
+	},
 	{
 		.name		= "max_threshold_occupancy",
 		.mode		= 0644,
@@ -1583,7 +1617,7 @@ static int rdtgroup_add_files(struct kernfs_node *kn, unsigned long fflags)
 	lockdep_assert_held(&rdtgroup_mutex);
 
 	for (rft = rfts; rft < rfts + len; rft++) {
-		if ((fflags & rft->fflags) == rft->fflags) {
+		if (rft->fflags && ((fflags & rft->fflags) == rft->fflags)) {
 			ret = rdtgroup_add_file(kn, rft);
 			if (ret)
 				goto error;
@@ -1600,6 +1634,33 @@ error:
 	return ret;
 }
 
+static struct rftype *rdtgroup_get_rftype_by_name(const char *name)
+{
+	struct rftype *rfts, *rft;
+	int len;
+
+	rfts = res_common_files;
+	len = ARRAY_SIZE(res_common_files);
+
+	for (rft = rfts; rft < rfts + len; rft++) {
+		if (!strcmp(rft->name, name))
+			return rft;
+	}
+
+	return NULL;
+}
+
+void __init thread_throttle_mode_init(void)
+{
+	struct rftype *rft;
+
+	rft = rdtgroup_get_rftype_by_name("thread_throttle_mode");
+	if (!rft)
+		return;
+
+	rft->fflags = RF_CTRL_INFO | RFTYPE_RES_MB;
+}
+
 /**
  * rdtgroup_kn_mode_restrict - Restrict user access to named resctrl file
  * @r: The resource group with which the file is associated.
@@ -2245,18 +2306,6 @@ static int reset_all_ctrls(struct rdt_resource *r)
 	return 0;
 }
 
-static bool is_closid_match(struct task_struct *t, struct rdtgroup *r)
-{
-	return (rdt_alloc_capable &&
-		(r->type == RDTCTRL_GROUP) && (t->closid == r->closid));
-}
-
-static bool is_rmid_match(struct task_struct *t, struct rdtgroup *r)
-{
-	return (rdt_mon_capable &&
-		(r->type == RDTMON_GROUP) && (t->rmid == r->mon.rmid));
-}
-
 /*
  * Move tasks from one to the other group. If @from is NULL, then all tasks
  * in the systems are moved unconditionally (used for teardown).
@@ -3196,7 +3245,7 @@ int __init rdtgroup_init(void)
 	 * It may also be ok since that would enable debugging of RDT before
 	 * resctrl is mounted.
 	 * The reason why the debugfs directory is created here and not in
-	 * rdt_mount() is because rdt_mount() takes rdtgroup_mutex and
+	 * rdt_get_tree() is because rdt_get_tree() takes rdtgroup_mutex and
 	 * during the debugfs directory creation also &sb->s_type->i_mutex_key
 	 * (the lockdep class of inode->i_rwsem). Other filesystem
 	 * interactions (eg. SyS_getdents) have the lock ordering: