Merge tag 'cgroup-for-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup updates from Tejun Heo:

 - Whenever cpuset needs to rebuild sched_domain, it walked all tasks
   looking for DEADLINE tasks as they need to be accounted on the new
   domain. Walking all tasks can be expensive and there may not be any
   DEADLINE tasks at all. Task iteration is now omitted if there are no
   DEADLINE tasks

 - Fixes DEADLINE bandwidth misaccounting after task migration failures

 - When no controller is enabled, -Wstringop-overflow warning is
   triggered. The fix patch added an early exit which is too eager and
   got reverted for now. Will fix later

 - Everything else is minor cleanups

* tag 'cgroup-for-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  Revert "cgroup: Avoid -Wstringop-overflow warnings"
  cgroup/misc: Expose misc.current on cgroup v2 root
  cgroup: Avoid -Wstringop-overflow warnings
  cgroup: remove obsolete comment on cgroup_on_dfl()
  cgroup: remove unused task_cgroup_path()
  cgroup/cpuset: remove unneeded header files
  cgroup: make cgroup_is_threaded() and cgroup_is_thread_root() static
  rdmacg: fix kernel-doc warnings in rdmacg
  cgroup: Replace the css_set call with cgroup_get
  cgroup: remove unused macro for_each_e_css()
  cgroup: Update out-of-date comment in cgroup_migrate()
  cgroup: Replace all non-returning strlcpy with strscpy
  cgroup/cpuset: remove unneeded header files
  cgroup/cpuset: Free DL BW in case can_attach() fails
  sched/deadline: Create DL BW alloc, free & check overflow interface
  cgroup/cpuset: Iterate only if DEADLINE tasks are present
  sched/cpuset: Keep track of SCHED_DEADLINE task in cpusets
  sched/cpuset: Bring back cpuset_mutex
  cgroup/cpuset: Rename functions dealing with DEADLINE accounting

6 files changed, 172 insertions, 176 deletions

diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h
index 367b0a42ada90..c56071f150f2a 100644
--- a/kernel/cgroup/cgroup-internal.h
+++ b/kernel/cgroup/cgroup-internal.h
@@ -220,8 +220,6 @@ static inline void get_css_set(struct css_set *cset)
 
 bool cgroup_ssid_enabled(int ssid);
 bool cgroup_on_dfl(const struct cgroup *cgrp);
-bool cgroup_is_thread_root(struct cgroup *cgrp);
-bool cgroup_is_threaded(struct cgroup *cgrp);
 
 struct cgroup_root *cgroup_root_from_kf(struct kernfs_root *kf_root);
 struct cgroup *task_cgroup_from_root(struct task_struct *task,
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 5407241dbb45f..83044312bc413 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -563,7 +563,7 @@ static ssize_t cgroup_release_agent_write(struct kernfs_open_file *of,
 	if (!cgrp)
 		return -ENODEV;
 	spin_lock(&release_agent_path_lock);
-	strlcpy(cgrp->root->release_agent_path, strstrip(buf),
+	strscpy(cgrp->root->release_agent_path, strstrip(buf),
 		sizeof(cgrp->root->release_agent_path));
 	spin_unlock(&release_agent_path_lock);
 	cgroup_kn_unlock(of->kn);
@@ -797,7 +797,7 @@ void cgroup1_release_agent(struct work_struct *work)
 		goto out_free;
 
 	spin_lock(&release_agent_path_lock);
-	strlcpy(agentbuf, cgrp->root->release_agent_path, PATH_MAX);
+	strscpy(agentbuf, cgrp->root->release_agent_path, PATH_MAX);
 	spin_unlock(&release_agent_path_lock);
 	if (!agentbuf[0])
 		goto out_free;
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 8f917f682f52c..bfe3cd8ccf366 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -57,6 +57,7 @@
 #include <linux/file.h>
 #include <linux/fs_parser.h>
 #include <linux/sched/cputime.h>
+#include <linux/sched/deadline.h>
 #include <linux/psi.h>
 #include <net/sock.h>
 
@@ -312,8 +313,6 @@ bool cgroup_ssid_enabled(int ssid)
  *   masks of ancestors.
  *
  * - blkcg: blk-throttle becomes properly hierarchical.
- *
- * - debug: disallowed on the default hierarchy.
  */
 bool cgroup_on_dfl(const struct cgroup *cgrp)
 {
@@ -356,7 +355,7 @@ static bool cgroup_has_tasks(struct cgroup *cgrp)
 	return cgrp->nr_populated_csets;
 }
 
-bool cgroup_is_threaded(struct cgroup *cgrp)
+static bool cgroup_is_threaded(struct cgroup *cgrp)
 {
 	return cgrp->dom_cgrp != cgrp;
 }
@@ -395,7 +394,7 @@ static bool cgroup_can_be_thread_root(struct cgroup *cgrp)
 }
 
 /* is @cgrp root of a threaded subtree? */
-bool cgroup_is_thread_root(struct cgroup *cgrp)
+static bool cgroup_is_thread_root(struct cgroup *cgrp)
 {
 	/* thread root should be a domain */
 	if (cgroup_is_threaded(cgrp))
@@ -618,7 +617,7 @@ EXPORT_SYMBOL_GPL(cgroup_get_e_css);
 static void cgroup_get_live(struct cgroup *cgrp)
 {
 	WARN_ON_ONCE(cgroup_is_dead(cgrp));
-	css_get(&cgrp->self);
+	cgroup_get(cgrp);
 }
 
 /**
@@ -690,21 +689,6 @@ EXPORT_SYMBOL_GPL(of_css);
 		else
 
 /**
- * for_each_e_css - iterate all effective css's of a cgroup
- * @css: the iteration cursor
- * @ssid: the index of the subsystem, CGROUP_SUBSYS_COUNT after reaching the end
- * @cgrp: the target cgroup to iterate css's of
- *
- * Should be called under cgroup_[tree_]mutex.
- */
-#define for_each_e_css(css, ssid, cgrp)					    \
-	for ((ssid) = 0; (ssid) < CGROUP_SUBSYS_COUNT; (ssid)++)	    \
-		if (!((css) = cgroup_e_css_by_mask(cgrp,		    \
-						   cgroup_subsys[(ssid)]))) \
-			;						    \
-		else
-
-/**
  * do_each_subsys_mask - filter for_each_subsys with a bitmask
  * @ss: the iteration cursor
  * @ssid: the index of @ss, CGROUP_SUBSYS_COUNT after reaching the end
@@ -2393,45 +2377,6 @@ int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
 EXPORT_SYMBOL_GPL(cgroup_path_ns);
 
 /**
- * task_cgroup_path - cgroup path of a task in the first cgroup hierarchy
- * @task: target task
- * @buf: the buffer to write the path into
- * @buflen: the length of the buffer
- *
- * Determine @task's cgroup on the first (the one with the lowest non-zero
- * hierarchy_id) cgroup hierarchy and copy its path into @buf.  This
- * function grabs cgroup_mutex and shouldn't be used inside locks used by
- * cgroup controller callbacks.
- *
- * Return value is the same as kernfs_path().
- */
-int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen)
-{
-	struct cgroup_root *root;
-	struct cgroup *cgrp;
-	int hierarchy_id = 1;
-	int ret;
-
-	cgroup_lock();
-	spin_lock_irq(&css_set_lock);
-
-	root = idr_get_next(&cgroup_hierarchy_idr, &hierarchy_id);
-
-	if (root) {
-		cgrp = task_cgroup_from_root(task, root);
-		ret = cgroup_path_ns_locked(cgrp, buf, buflen, &init_cgroup_ns);
-	} else {
-		/* if no hierarchy exists, everyone is in "/" */
-		ret = strscpy(buf, "/", buflen);
-	}
-
-	spin_unlock_irq(&css_set_lock);
-	cgroup_unlock();
-	return ret;
-}
-EXPORT_SYMBOL_GPL(task_cgroup_path);
-
-/**
  * cgroup_attach_lock - Lock for ->attach()
  * @lock_threadgroup: whether to down_write cgroup_threadgroup_rwsem
  *
@@ -2885,9 +2830,9 @@ int cgroup_migrate(struct task_struct *leader, bool threadgroup,
 	struct task_struct *task;
 
 	/*
-	 * Prevent freeing of tasks while we take a snapshot. Tasks that are
-	 * already PF_EXITING could be freed from underneath us unless we
-	 * take an rcu_read_lock.
+	 * The following thread iteration should be inside an RCU critical
+	 * section to prevent tasks from being freed while taking the snapshot.
+	 * spin_lock_irq() implies RCU critical section here.
 	 */
 	spin_lock_irq(&css_set_lock);
 	task = leader;
@@ -6708,6 +6653,9 @@ void cgroup_exit(struct task_struct *tsk)
 	list_add_tail(&tsk->cg_list, &cset->dying_tasks);
 	cset->nr_tasks--;
 
+	if (dl_task(tsk))
+		dec_dl_tasks_cs(tsk);
+
 	WARN_ON_ONCE(cgroup_task_frozen(tsk));
 	if (unlikely(!(tsk->flags & PF_KTHREAD) &&
 		     test_bit(CGRP_FREEZE, &task_dfl_cgroup(tsk)->flags)))
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index e4ca2dd2b7648..58e6f18f01c1b 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -25,45 +25,22 @@
 #include <linux/cpu.h>
 #include <linux/cpumask.h>
 #include <linux/cpuset.h>
-#include <linux/err.h>
-#include <linux/errno.h>
-#include <linux/file.h>
-#include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
-#include <linux/kmod.h>
-#include <linux/kthread.h>
-#include <linux/list.h>
 #include <linux/mempolicy.h>
 #include <linux/mm.h>
 #include <linux/memory.h>
 #include <linux/export.h>
-#include <linux/mount.h>
-#include <linux/fs_context.h>
-#include <linux/namei.h>
-#include <linux/pagemap.h>
-#include <linux/proc_fs.h>
 #include <linux/rcupdate.h>
 #include <linux/sched.h>
 #include <linux/sched/deadline.h>
 #include <linux/sched/mm.h>
 #include <linux/sched/task.h>
-#include <linux/seq_file.h>
 #include <linux/security.h>
-#include <linux/slab.h>
 #include <linux/spinlock.h>
-#include <linux/stat.h>
-#include <linux/string.h>
-#include <linux/time.h>
-#include <linux/time64.h>
-#include <linux/backing-dev.h>
-#include <linux/sort.h>
 #include <linux/oom.h>
 #include <linux/sched/isolation.h>
-#include <linux/uaccess.h>
-#include <linux/atomic.h>
-#include <linux/mutex.h>
 #include <linux/cgroup.h>
 #include <linux/wait.h>
 
@@ -193,6 +170,14 @@ struct cpuset {
 	int use_parent_ecpus;
 	int child_ecpus_count;
 
+	/*
+	 * number of SCHED_DEADLINE tasks attached to this cpuset, so that we
+	 * know when to rebuild associated root domain bandwidth information.
+	 */
+	int nr_deadline_tasks;
+	int nr_migrate_dl_tasks;
+	u64 sum_migrate_dl_bw;
+
 	/* Invalid partition error code, not lock protected */
 	enum prs_errcode prs_err;
 
@@ -245,6 +230,20 @@ static inline struct cpuset *parent_cs(struct cpuset *cs)
 	return css_cs(cs->css.parent);
 }
 
+void inc_dl_tasks_cs(struct task_struct *p)
+{
+	struct cpuset *cs = task_cs(p);
+
+	cs->nr_deadline_tasks++;
+}
+
+void dec_dl_tasks_cs(struct task_struct *p)
+{
+	struct cpuset *cs = task_cs(p);
+
+	cs->nr_deadline_tasks--;
+}
+
 /* bits in struct cpuset flags field */
 typedef enum {
 	CS_ONLINE,
@@ -366,22 +365,23 @@ static struct cpuset top_cpuset = {
 		if (is_cpuset_online(((des_cs) = css_cs((pos_css)))))
 
 /*
- * There are two global locks guarding cpuset structures - cpuset_rwsem and
+ * There are two global locks guarding cpuset structures - cpuset_mutex and
  * callback_lock. We also require taking task_lock() when dereferencing a
  * task's cpuset pointer. See "The task_lock() exception", at the end of this
- * comment.  The cpuset code uses only cpuset_rwsem write lock.  Other
- * kernel subsystems can use cpuset_read_lock()/cpuset_read_unlock() to
- * prevent change to cpuset structures.
+ * comment.  The cpuset code uses only cpuset_mutex. Other kernel subsystems
+ * can use cpuset_lock()/cpuset_unlock() to prevent change to cpuset
+ * structures. Note that cpuset_mutex needs to be a mutex as it is used in
+ * paths that rely on priority inheritance (e.g. scheduler - on RT) for
+ * correctness.
  *
  * A task must hold both locks to modify cpusets.  If a task holds
- * cpuset_rwsem, it blocks others wanting that rwsem, ensuring that it
- * is the only task able to also acquire callback_lock and be able to
- * modify cpusets.  It can perform various checks on the cpuset structure
- * first, knowing nothing will change.  It can also allocate memory while
- * just holding cpuset_rwsem.  While it is performing these checks, various
- * callback routines can briefly acquire callback_lock to query cpusets.
- * Once it is ready to make the changes, it takes callback_lock, blocking
- * everyone else.
+ * cpuset_mutex, it blocks others, ensuring that it is the only task able to
+ * also acquire callback_lock and be able to modify cpusets.  It can perform
+ * various checks on the cpuset structure first, knowing nothing will change.
+ * It can also allocate memory while just holding cpuset_mutex.  While it is
+ * performing these checks, various callback routines can briefly acquire
+ * callback_lock to query cpusets.  Once it is ready to make the changes, it
+ * takes callback_lock, blocking everyone else.
  *
  * Calls to the kernel memory allocator can not be made while holding
  * callback_lock, as that would risk double tripping on callback_lock
@@ -403,16 +403,16 @@ static struct cpuset top_cpuset = {
  * guidelines for accessing subsystem state in kernel/cgroup.c
  */
 
-DEFINE_STATIC_PERCPU_RWSEM(cpuset_rwsem);
+static DEFINE_MUTEX(cpuset_mutex);
 
-void cpuset_read_lock(void)
+void cpuset_lock(void)
 {
-	percpu_down_read(&cpuset_rwsem);
+	mutex_lock(&cpuset_mutex);
 }
 
-void cpuset_read_unlock(void)
+void cpuset_unlock(void)
 {
-	percpu_up_read(&cpuset_rwsem);
+	mutex_unlock(&cpuset_mutex);
 }
 
 static DEFINE_SPINLOCK(callback_lock);
@@ -496,7 +496,7 @@ static inline bool partition_is_populated(struct cpuset *cs,
  * One way or another, we guarantee to return some non-empty subset
  * of cpu_online_mask.
  *
- * Call with callback_lock or cpuset_rwsem held.
+ * Call with callback_lock or cpuset_mutex held.
  */
 static void guarantee_online_cpus(struct task_struct *tsk,
 				  struct cpumask *pmask)
@@ -538,7 +538,7 @@ out_unlock:
  * One way or another, we guarantee to return some non-empty subset
  * of node_states[N_MEMORY].
  *
- * Call with callback_lock or cpuset_rwsem held.
+ * Call with callback_lock or cpuset_mutex held.
  */
 static void guarantee_online_mems(struct cpuset *cs, nodemask_t *pmask)
 {
@@ -550,7 +550,7 @@ static void guarantee_online_mems(struct cpuset *cs, nodemask_t *pmask)
 /*
  * update task's spread flag if cpuset's page/slab spread flag is set
  *
- * Call with callback_lock or cpuset_rwsem held. The check can be skipped
+ * Call with callback_lock or cpuset_mutex held. The check can be skipped
  * if on default hierarchy.
  */
 static void cpuset_update_task_spread_flags(struct cpuset *cs,
@@ -575,7 +575,7 @@ static void cpuset_update_task_spread_flags(struct cpuset *cs,
  *
  * One cpuset is a subset of another if all its allowed CPUs and
  * Memory Nodes are a subset of the other, and its exclusive flags
- * are only set if the other's are set.  Call holding cpuset_rwsem.
+ * are only set if the other's are set.  Call holding cpuset_mutex.
  */
 
 static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q)
@@ -713,7 +713,7 @@ out:
  * If we replaced the flag and mask values of the current cpuset
  * (cur) with those values in the trial cpuset (trial), would
  * our various subset and exclusive rules still be valid?  Presumes
- * cpuset_rwsem held.
+ * cpuset_mutex held.
  *
  * 'cur' is the address of an actual, in-use cpuset.  Operations
  * such as list traversal that depend on the actual address of the
@@ -829,7 +829,7 @@ static void update_domain_attr_tree(struct sched_domain_attr *dattr,
 	rcu_read_unlock();
 }
 
-/* Must be called with cpuset_rwsem held.  */
+/* Must be called with cpuset_mutex held.  */
 static inline int nr_cpusets(void)
 {
 	/* jump label reference count + the top-level cpuset */
@@ -855,7 +855,7 @@ static inline int nr_cpusets(void)
  * domains when operating in the severe memory shortage situations
  * that could cause allocation failures below.
  *
- * Must be called with cpuset_rwsem held.
+ * Must be called with cpuset_mutex held.
  *
  * The three key local variables below are:
  *    cp - cpuset pointer, used (together with pos_css) to perform a
@@ -1066,11 +1066,14 @@ done:
 	return ndoms;
 }
 
-static void update_tasks_root_domain(struct cpuset *cs)
+static void dl_update_tasks_root_domain(struct cpuset *cs)
 {
 	struct css_task_iter it;
 	struct task_struct *task;
 
+	if (cs->nr_deadline_tasks == 0)
+		return;
+
 	css_task_iter_start(&cs->css, 0, &it);
 
 	while ((task = css_task_iter_next(&it)))
@@ -1079,12 +1082,12 @@ static void update_tasks_root_domain(struct cpuset *cs)
 	css_task_iter_end(&it);
 }
 
-static void rebuild_root_domains(void)
+static void dl_rebuild_rd_accounting(void)
 {
 	struct cpuset *cs = NULL;
 	struct cgroup_subsys_state *pos_css;
 
-	percpu_rwsem_assert_held(&cpuset_rwsem);
+	lockdep_assert_held(&cpuset_mutex);
 	lockdep_assert_cpus_held();
 	lockdep_assert_held(&sched_domains_mutex);
 
@@ -1107,7 +1110,7 @@ static void rebuild_root_domains(void)
 
 		rcu_read_unlock();
 
-		update_tasks_root_domain(cs);
+		dl_update_tasks_root_domain(cs);
 
 		rcu_read_lock();
 		css_put(&cs->css);
@@ -1121,7 +1124,7 @@ partition_and_rebuild_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
 {
 	mutex_lock(&sched_domains_mutex);
 	partition_sched_domains_locked(ndoms_new, doms_new, dattr_new);
-	rebuild_root_domains();
+	dl_rebuild_rd_accounting();
 	mutex_unlock(&sched_domains_mutex);
 }
 
@@ -1134,7 +1137,7 @@ partition_and_rebuild_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
  * 'cpus' is removed, then call this routine to rebuild the
  * scheduler's dynamic sched domains.
  *
- * Call with cpuset_rwsem held.  Takes cpus_read_lock().
+ * Call with cpuset_mutex held.  Takes cpus_read_lock().
  */
 static void rebuild_sched_domains_locked(void)
 {
@@ -1145,7 +1148,7 @@ static void rebuild_sched_domains_locked(void)
 	int ndoms;
 
 	lockdep_assert_cpus_held();
-	percpu_rwsem_assert_held(&cpuset_rwsem);
+	lockdep_assert_held(&cpuset_mutex);
 
 	/*
 	 * If we have raced with CPU hotplug, return early to avoid
@@ -1196,9 +1199,9 @@ static void rebuild_sched_domains_locked(void)
 void rebuild_sched_domains(void)
 {
 	cpus_read_lock();
-	percpu_down_write(&cpuset_rwsem);
+	mutex_lock(&cpuset_mutex);
 	rebuild_sched_domains_locked();
-	percpu_up_write(&cpuset_rwsem);
+	mutex_unlock(&cpuset_mutex);
 	cpus_read_unlock();
 }
 
@@ -1208,7 +1211,7 @@ void rebuild_sched_domains(void)
  * @new_cpus: the temp variable for the new effective_cpus mask
  *
  * Iterate through each task of @cs updating its cpus_allowed to the
- * effective cpuset's.  As this function is called with cpuset_rwsem held,
+ * effective cpuset's.  As this function is called with cpuset_mutex held,
  * cpuset membership stays stable. For top_cpuset, task_cpu_possible_mask()
  * is used instead of effective_cpus to make sure all offline CPUs are also
  * included as hotplug code won't update cpumasks for tasks in top_cpuset.
@@ -1322,7 +1325,7 @@ static int update_parent_subparts_cpumask(struct cpuset *cs, int cmd,
 	int old_prs, new_prs;
 	int part_error = PERR_NONE;	/* Partition error? */
 
-	percpu_rwsem_assert_held(&cpuset_rwsem);
+	lockdep_assert_held(&cpuset_mutex);
 
 	/*
 	 * The parent must be a partition root.
@@ -1545,7 +1548,7 @@ static int update_parent_subparts_cpumask(struct cpuset *cs, int cmd,
  *
  * On legacy hierarchy, effective_cpus will be the same with cpu_allowed.
  *
- * Called with cpuset_rwsem held
+ * Called with cpuset_mutex held
  */
 static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp,
 				 bool force)
@@ -1705,7 +1708,7 @@ static void update_sibling_cpumasks(struct cpuset *parent, struct cpuset *cs,
 	struct cpuset *sibling;
 	struct cgroup_subsys_state *pos_css;
 
-	percpu_rwsem_assert_held(&cpuset_rwsem);
+	lockdep_assert_held(&cpuset_mutex);
 
 	/*
 	 * Check all its siblings and call update_cpumasks_hier()
@@ -1955,12 +1958,12 @@ static void *cpuset_being_rebound;
  * @cs: the cpuset in which each task's mems_allowed mask needs to be changed
  *
  * Iterate through each task of @cs updating its mems_allowed to the
- * effective cpuset's.  As this function is called with cpuset_rwsem held,
+ * effective cpuset's.  As this function is called with cpuset_mutex held,
  * cpuset membership stays stable.
  */
 static void update_tasks_nodemask(struct cpuset *cs)
 {
-	static nodemask_t newmems;	/* protected by cpuset_rwsem */
+	static nodemask_t newmems;	/* protected by cpuset_mutex */
 	struct css_task_iter it;
 	struct task_struct *task;
 
@@ -1973,7 +1976,7 @@ static void update_tasks_nodemask(struct cpuset *cs)
 	 * take while holding tasklist_lock.  Forks can happen - the
 	 * mpol_dup() cpuset_being_rebound check will catch such forks,
 	 * and rebind their vma mempolicies too.  Because we still hold
-	 * the global cpuset_rwsem, we know that no other rebind effort
+	 * the global cpuset_mutex, we know that no other rebind effort
 	 * will be contending for the global variable cpuset_being_rebound.
 	 * It's ok if we rebind the same mm twice; mpol_rebind_mm()
 	 * is idempotent.  Also migrate pages in each mm to new nodes.
@@ -2019,7 +2022,7 @@ static void update_tasks_nodemask(struct cpuset *cs)
  *
  * On legacy hierarchy, effective_mems will be the same with mems_allowed.
  *
- * Called with cpuset_rwsem held
+ * Called with cpuset_mutex held
  */
 static void update_nodemasks_hier(struct cpuset *cs, nodemask_t *new_mems)
 {
@@ -2072,7 +2075,7 @@ static void update_nodemasks_hier(struct cpuset *cs, nodemask_t *new_mems)
  * mempolicies and if the cpuset is marked 'memory_migrate',
  * migrate the tasks pages to the new memory.
  *
- * Call with cpuset_rwsem held. May take callback_lock during call.
+ * Call with cpuset_mutex held. May take callback_lock during call.
  * Will take tasklist_lock, scan tasklist for tasks in cpuset cs,
  * lock each such tasks mm->mmap_lock, scan its vma's and rebind
  * their mempolicies to the cpusets new mems_allowed.
@@ -2164,7 +2167,7 @@ static int update_relax_domain_level(struct cpuset *cs, s64 val)
  * @cs: the cpuset in which each task's spread flags needs to be changed
  *
  * Iterate through each task of @cs updating its spread flags.  As this
- * function is called with cpuset_rwsem held, cpuset membership stays
+ * function is called with cpuset_mutex held, cpuset membership stays
  * stable.
  */
 static void update_tasks_flags(struct cpuset *cs)
@@ -2184,7 +2187,7 @@ static void update_tasks_flags(struct cpuset *cs)
  * cs:		the cpuset to update
  * turning_on: 	whether the flag is being set or cleared
  *
- * Call with cpuset_rwsem held.
+ * Call with cpuset_mutex held.
  */
 
 static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
@@ -2234,7 +2237,7 @@ out:
  * @new_prs: new partition root state
  * Return: 0 if successful, != 0 if error
  *
- * Call with cpuset_rwsem held.
+ * Call with cpuset_mutex held.
  */
 static int update_prstate(struct cpuset *cs, int new_prs)
 {
@@ -2472,19 +2475,26 @@ static int cpuset_can_attach_check(struct cpuset *cs)
 	return 0;
 }
 
-/* Called by cgroups to determine if a cpuset is usable; cpuset_rwsem held */
+static void reset_migrate_dl_data(struct cpuset *cs)
+{
+	cs->nr_migrate_dl_tasks = 0;
+	cs->sum_migrate_dl_bw = 0;
+}
+
+/* Called by cgroups to determine if a cpuset is usable; cpuset_mutex held */
 static int cpuset_can_attach(struct cgroup_taskset *tset)
 {
 	struct cgroup_subsys_state *css;
-	struct cpuset *cs;
+	struct cpuset *cs, *oldcs;
 	struct task_struct *task;
 	int ret;
 
 	/* used later by cpuset_attach() */
 	cpuset_attach_old_cs = task_cs(cgroup_taskset_first(tset, &css));
+	oldcs = cpuset_attach_old_cs;
 	cs = css_cs(css);
 
-	percpu_down_write(&cpuset_rwsem);
+	mutex_lock(&cpuset_mutex);
 
 	/* Check to see if task is allowed in the cpuset */
 	ret = cpuset_can_attach_check(cs);
@@ -2492,21 +2502,46 @@ static int cpuset_can_attach(struct cgroup_taskset *tset)
 		goto out_unlock;
 
 	cgroup_taskset_for_each(task, css, tset) {
-		ret = task_can_attach(task, cs->effective_cpus);
+		ret = task_can_attach(task);
 		if (ret)
 			goto out_unlock;
 		ret = security_task_setscheduler(task);
 		if (ret)
 			goto out_unlock;
+
+		if (dl_task(task)) {
+			cs->nr_migrate_dl_tasks++;
+			cs->sum_migrate_dl_bw += task->dl.dl_bw;
+		}
 	}
 
+	if (!cs->nr_migrate_dl_tasks)
+		goto out_success;
+
+	if (!cpumask_intersects(oldcs->effective_cpus, cs->effective_cpus)) {
+		int cpu = cpumask_any_and(cpu_active_mask, cs->effective_cpus);
+
+		if (unlikely(cpu >= nr_cpu_ids)) {
+			reset_migrate_dl_data(cs);
+			ret = -EINVAL;
+			goto out_unlock;
+		}
+
+		ret = dl_bw_alloc(cpu, cs->sum_migrate_dl_bw);
+		if (ret) {
+			reset_migrate_dl_data(cs);
+			goto out_unlock;
+		}
+	}
+
+out_success:
 	/*
 	 * Mark attach is in progress.  This makes validate_change() fail
 	 * changes which zero cpus/mems_allowed.
 	 */
 	cs->attach_in_progress++;
 out_unlock:
-	percpu_up_write(&cpuset_rwsem);
+	mutex_unlock(&cpuset_mutex);
 	return ret;
 }
 
@@ -2518,15 +2553,23 @@ static void cpuset_cancel_attach(struct cgroup_taskset *tset)
 	cgroup_taskset_first(tset, &css);
 	cs = css_cs(css);
 
-	percpu_down_write(&cpuset_rwsem);
+	mutex_lock(&cpuset_mutex);
 	cs->attach_in_progress--;
 	if (!cs->attach_in_progress)
 		wake_up(&cpuset_attach_wq);
-	percpu_up_write(&cpuset_rwsem);
+
+	if (cs->nr_migrate_dl_tasks) {
+		int cpu = cpumask_any(cs->effective_cpus);
+
+		dl_bw_free(cpu, cs->sum_migrate_dl_bw);
+		reset_migrate_dl_data(cs);
+	}
+
+	mutex_unlock(&cpuset_mutex);
 }
 
 /*
- * Protected by cpuset_rwsem. cpus_attach is used only by cpuset_attach_task()
+ * Protected by cpuset_mutex. cpus_attach is used only by cpuset_attach_task()
  * but we can't allocate it dynamically there.  Define it global and
  * allocate from cpuset_init().
  */
@@ -2535,7 +2578,7 @@ static nodemask_t cpuset_attach_nodemask_to;
 
 static void cpuset_attach_task(struct cpuset *cs, struct task_struct *task)
 {
-	percpu_rwsem_assert_held(&cpuset_rwsem);
+	lockdep_assert_held(&cpuset_mutex);
 
 	if (cs != &top_cpuset)
 		guarantee_online_cpus(task, cpus_attach);
@@ -2565,7 +2608,7 @@ static void cpuset_attach(struct cgroup_taskset *tset)
 	cs = css_cs(css);
 
 	lockdep_assert_cpus_held();	/* see cgroup_attach_lock() */
-	percpu_down_write(&cpuset_rwsem);
+	mutex_lock(&cpuset_mutex);
 	cpus_updated = !cpumask_equal(cs->effective_cpus,
 				      oldcs->effective_cpus);
 	mems_updated = !nodes_equal(cs->effective_mems, oldcs->effective_mems);
@@ -2622,11 +2665,17 @@ static void cpuset_attach(struct cgroup_taskset *tset)
 out:
 	cs->old_mems_allowed = cpuset_attach_nodemask_to;
 
+	if (cs->nr_migrate_dl_tasks) {
+		cs->nr_deadline_tasks += cs->nr_migrate_dl_tasks;
+		oldcs->nr_deadline_tasks -= cs->nr_migrate_dl_tasks;
+		reset_migrate_dl_data(cs);
+	}
+
 	cs->attach_in_progress--;
 	if (!cs->attach_in_progress)
 		wake_up(&cpuset_attach_wq);
 
-	percpu_up_write(&cpuset_rwsem);
+	mutex_unlock(&cpuset_mutex);
 }
 
 /* The various types of files and directories in a cpuset file system */
@@ -2658,7 +2707,7 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft,
 	int retval = 0;
 
 	cpus_read_lock();
-	percpu_down_write(&cpuset_rwsem);
+	mutex_lock(&cpuset_mutex);
 	if (!is_cpuset_online(cs)) {
 		retval = -ENODEV;
 		goto out_unlock;
@@ -2694,7 +2743,7 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft,
 		break;
 	}
 out_unlock:
-	percpu_up_write(&cpuset_rwsem);
+	mutex_unlock(&cpuset_mutex);
 	cpus_read_unlock();
 	return retval;
 }
@@ -2707,7 +2756,7 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
 	int retval = -ENODEV;
 
 	cpus_read_lock();
-	percpu_down_write(&cpuset_rwsem);
+	mutex_lock(&cpuset_mutex);
 	if (!is_cpuset_online(cs))
 		goto out_unlock;
 
@@ -2720,7 +2769,7 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
 		break;
 	}
 out_unlock:
-	percpu_up_write(&cpuset_rwsem);
+	mutex_unlock(&cpuset_mutex);
 	cpus_read_unlock();
 	return retval;
 }
@@ -2753,7 +2802,7 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of,
 	 * operation like this one can lead to a deadlock through kernfs
 	 * active_ref protection.  Let's break the protection.  Losing the
 	 * protection is okay as we check whether @cs is online after
-	 * grabbing cpuset_rwsem anyway.  This only happens on the legacy
+	 * grabbing cpuset_mutex anyway.  This only happens on the legacy
 	 * hierarchies.
 	 */
 	css_get(&cs->css);
@@ -2761,7 +2810,7 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of,
 	flush_work(&cpuset_hotplug_work);
 
 	cpus_read_lock();
-	percpu_down_write(&cpuset_rwsem);
+	mutex_lock(&cpuset_mutex);
 	if (!is_cpuset_online(cs))
 		goto out_unlock;
 
@@ -2785,7 +2834,7 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of,
 
 	free_cpuset(trialcs);
 out_unlock:
-	percpu_up_write(&cpuset_rwsem);
+	mutex_unlock(&cpuset_mutex);
 	cpus_read_unlock();
 	kernfs_unbreak_active_protection(of->kn);
 	css_put(&cs->css);
@@ -2933,13 +2982,13 @@ static ssize_t sched_partition_write(struct kernfs_open_file *of, char *buf,
 
 	css_get(&cs->css);
 	cpus_read_lock();
-	percpu_down_write(&cpuset_rwsem);
+	mutex_lock(&cpuset_mutex);
 	if (!is_cpuset_online(cs))
 		goto out_unlock;
 
 	retval = update_prstate(cs, val);
 out_unlock:
-	percpu_up_write(&cpuset_rwsem);
+	mutex_unlock(&cpuset_mutex);
 	cpus_read_unlock();
 	css_put(&cs->css);
 	return retval ?: nbytes;
@@ -3156,7 +3205,7 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
 		return 0;
 
 	cpus_read_lock();
-	percpu_down_write(&cpuset_rwsem);
+	mutex_lock(&cpuset_mutex);
 
 	set_bit(CS_ONLINE, &cs->flags);
 	if (is_spread_page(parent))
@@ -3207,7 +3256,7 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
 	cpumask_copy(cs->effective_cpus, parent->cpus_allowed);
 	spin_unlock_irq(&callback_lock);
 out_unlock:
-	percpu_up_write(&cpuset_rwsem);
+	mutex_unlock(&cpuset_mutex);
 	cpus_read_unlock();
 	return 0;
 }
@@ -3228,7 +3277,7 @@ static void cpuset_css_offline(struct cgroup_subsys_state *css)
 	struct cpuset *cs = css_cs(css);
 
 	cpus_read_lock();
-	percpu_down_write(&cpuset_rwsem);
+	mutex_lock(&cpuset_mutex);
 
 	if (is_partition_valid(cs))
 		update_prstate(cs, 0);
@@ -3247,7 +3296,7 @@ static void cpuset_css_offline(struct cgroup_subsys_state *css)
 	cpuset_dec();
 	clear_bit(CS_ONLINE, &cs->flags);
 
-	percpu_up_write(&cpuset_rwsem);
+	mutex_unlock(&cpuset_mutex);
 	cpus_read_unlock();
 }
 
@@ -3260,7 +3309,7 @@ static void cpuset_css_free(struct cgroup_subsys_state *css)
 
 static void cpuset_bind(struct cgroup_subsys_state *root_css)
 {
-	percpu_down_write(&cpuset_rwsem);
+	mutex_lock(&cpuset_mutex);
 	spin_lock_irq(&callback_lock);
 
 	if (is_in_v2_mode()) {
@@ -3273,7 +3322,7 @@ static void cpuset_bind(struct cgroup_subsys_state *root_css)
 	}
 
 	spin_unlock_irq(&callback_lock);
-	percpu_up_write(&cpuset_rwsem);
+	mutex_unlock(&cpuset_mutex);
 }
 
 /*
@@ -3294,14 +3343,14 @@ static int cpuset_can_fork(struct task_struct *task, struct css_set *cset)
 		return 0;
 
 	lockdep_assert_held(&cgroup_mutex);
-	percpu_down_write(&cpuset_rwsem);
+	mutex_lock(&cpuset_mutex);
 
 	/* Check to see if task is allowed in the cpuset */
 	ret = cpuset_can_attach_check(cs);
 	if (ret)
 		goto out_unlock;
 
-	ret = task_can_attach(task, cs->effective_cpus);
+	ret = task_can_attach(task);
 	if (ret)
 		goto out_unlock;
 
@@ -3315,7 +3364,7 @@ static int cpuset_can_fork(struct task_struct *task, struct css_set *cset)
 	 */
 	cs->attach_in_progress++;
 out_unlock:
-	percpu_up_write(&cpuset_rwsem);
+	mutex_unlock(&cpuset_mutex);
 	return ret;
 }
 
@@ -3331,11 +3380,11 @@ static void cpuset_cancel_fork(struct task_struct *task, struct css_set *cset)
 	if (same_cs)
 		return;
 
-	percpu_down_write(&cpuset_rwsem);
+	mutex_lock(&cpuset_mutex);
 	cs->attach_in_progress--;
 	if (!cs->attach_in_progress)
 		wake_up(&cpuset_attach_wq);
-	percpu_up_write(&cpuset_rwsem);
+	mutex_unlock(&cpuset_mutex);
 }
 
 /*
@@ -3363,7 +3412,7 @@ static void cpuset_fork(struct task_struct *task)
 	}
 
 	/* CLONE_INTO_CGROUP */
-	percpu_down_write(&cpuset_rwsem);
+	mutex_lock(&cpuset_mutex);
 	guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
 	cpuset_attach_task(cs, task);
 
@@ -3371,7 +3420,7 @@ static void cpuset_fork(struct task_struct *task)
 	if (!cs->attach_in_progress)
 		wake_up(&cpuset_attach_wq);
 
-	percpu_up_write(&cpuset_rwsem);
+	mutex_unlock(&cpuset_mutex);
 }
 
 struct cgroup_subsys cpuset_cgrp_subsys = {
@@ -3472,7 +3521,7 @@ hotplug_update_tasks_legacy(struct cpuset *cs,
 	is_empty = cpumask_empty(cs->cpus_allowed) ||
 		   nodes_empty(cs->mems_allowed);
 
-	percpu_up_write(&cpuset_rwsem);
+	mutex_unlock(&cpuset_mutex);
 
 	/*
 	 * Move tasks to the nearest ancestor with execution resources,
@@ -3482,7 +3531,7 @@ hotplug_update_tasks_legacy(struct cpuset *cs,
 	if (is_empty)
 		remove_tasks_in_empty_cpuset(cs);
 
-	percpu_down_write(&cpuset_rwsem);
+	mutex_lock(&cpuset_mutex);
 }
 
 static void
@@ -3533,14 +3582,14 @@ static void cpuset_hotplug_update_tasks(struct cpuset *cs, struct tmpmasks *tmp)
 retry:
 	wait_event(cpuset_attach_wq, cs->attach_in_progress == 0);
 
-	percpu_down_write(&cpuset_rwsem);
+	mutex_lock(&cpuset_mutex);
 
 	/*
 	 * We have raced with task attaching. We wait until attaching
 	 * is finished, so we won't attach a task to an empty cpuset.
 	 */
 	if (cs->attach_in_progress) {
-		percpu_up_write(&cpuset_rwsem);
+		mutex_unlock(&cpuset_mutex);
 		goto retry;
 	}
 
@@ -3637,7 +3686,7 @@ update_tasks:
 					    cpus_updated, mems_updated);
 
 unlock:
-	percpu_up_write(&cpuset_rwsem);
+	mutex_unlock(&cpuset_mutex);
 }
 
 /**
@@ -3667,7 +3716,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work)
 	if (on_dfl && !alloc_cpumasks(NULL, &tmp))
 		ptmp = &tmp;
 
-	percpu_down_write(&cpuset_rwsem);
+	mutex_lock(&cpuset_mutex);
 
 	/* fetch the available cpus/mems and find out which changed how */
 	cpumask_copy(&new_cpus, cpu_active_mask);
@@ -3724,7 +3773,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work)
 		update_tasks_nodemask(&top_cpuset);
 	}
 
-	percpu_up_write(&cpuset_rwsem);
+	mutex_unlock(&cpuset_mutex);
 
 	/* if cpus or mems changed, we need to propagate to descendants */
 	if (cpus_updated || mems_updated) {
@@ -4155,7 +4204,7 @@ void __cpuset_memory_pressure_bump(void)
  *  - Used for /proc/<pid>/cpuset.
  *  - No need to task_lock(tsk) on this tsk->cpuset reference, as it
  *    doesn't really matter if tsk->cpuset changes after we read it,
- *    and we take cpuset_rwsem, keeping cpuset_attach() from changing it
+ *    and we take cpuset_mutex, keeping cpuset_attach() from changing it
  *    anyway.
  */
 int proc_cpuset_show(struct seq_file *m, struct pid_namespace *ns,
diff --git a/kernel/cgroup/misc.c b/kernel/cgroup/misc.c
index fe3e8a0eb7ed1..ae2f4dd47508d 100644
--- a/kernel/cgroup/misc.c
+++ b/kernel/cgroup/misc.c
@@ -357,7 +357,6 @@ static struct cftype misc_cg_files[] = {
 	{
 		.name = "current",
 		.seq_show = misc_cg_current_show,
-		.flags = CFTYPE_NOT_ON_ROOT,
 	},
 	{
 		.name = "capacity",
diff --git a/kernel/cgroup/rdma.c b/kernel/cgroup/rdma.c
index 3135406608c75..ef5878fb20057 100644
--- a/kernel/cgroup/rdma.c
+++ b/kernel/cgroup/rdma.c
@@ -197,6 +197,7 @@ uncharge_cg_locked(struct rdma_cgroup *cg,
 
 /**
  * rdmacg_uncharge_hierarchy - hierarchically uncharge rdma resource count
+ * @cg: pointer to cg to uncharge and all parents in hierarchy
  * @device: pointer to rdmacg device
  * @stop_cg: while traversing hirerchy, when meet with stop_cg cgroup
  *           stop uncharging
@@ -221,6 +222,7 @@ static void rdmacg_uncharge_hierarchy(struct rdma_cgroup *cg,
 
 /**
  * rdmacg_uncharge - hierarchically uncharge rdma resource count
+ * @cg: pointer to cg to uncharge and all parents in hierarchy
  * @device: pointer to rdmacg device
  * @index: index of the resource to uncharge in cgroup in given resource pool
  */