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-rw-r--r--kernel/cgroup.c19
-rw-r--r--kernel/cpuset.c20
-rw-r--r--kernel/fork.c11
-rw-r--r--kernel/nsproxy.c27
-rw-r--r--kernel/pid_namespace.c4
-rw-r--r--kernel/power/qos.c20
-rw-r--r--kernel/sched/core.c96
-rw-r--r--kernel/sched/cpupri.c4
-rw-r--r--kernel/sched/fair.c10
-rw-r--r--kernel/time/sched_clock.c2
-rw-r--r--kernel/time/tick-sched.c5
-rw-r--r--kernel/time/timer_list.c41
-rw-r--r--kernel/wait.c3
-rw-r--r--kernel/workqueue.c9
14 files changed, 190 insertions, 81 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 781845a013a..e91963302c0 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4480,6 +4480,7 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
struct dentry *d = cgrp->dentry;
struct cgroup_event *event, *tmp;
struct cgroup_subsys *ss;
+ struct cgroup *child;
bool empty;
lockdep_assert_held(&d->d_inode->i_mutex);
@@ -4490,12 +4491,28 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
* @cgrp from being removed while __put_css_set() is in progress.
*/
read_lock(&css_set_lock);
- empty = list_empty(&cgrp->cset_links) && list_empty(&cgrp->children);
+ empty = list_empty(&cgrp->cset_links);
read_unlock(&css_set_lock);
if (!empty)
return -EBUSY;
/*
+ * Make sure there's no live children. We can't test ->children
+ * emptiness as dead children linger on it while being destroyed;
+ * otherwise, "rmdir parent/child parent" may fail with -EBUSY.
+ */
+ empty = true;
+ rcu_read_lock();
+ list_for_each_entry_rcu(child, &cgrp->children, sibling) {
+ empty = cgroup_is_dead(child);
+ if (!empty)
+ break;
+ }
+ rcu_read_unlock();
+ if (!empty)
+ return -EBUSY;
+
+ /*
* Block new css_tryget() by killing css refcnts. cgroup core
* guarantees that, by the time ->css_offline() is invoked, no new
* css reference will be given out via css_tryget(). We can't
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index e5657788fed..ea1966db34f 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -475,13 +475,17 @@ static int validate_change(const struct cpuset *cur, const struct cpuset *trial)
/*
* Cpusets with tasks - existing or newly being attached - can't
- * have empty cpus_allowed or mems_allowed.
+ * be changed to have empty cpus_allowed or mems_allowed.
*/
ret = -ENOSPC;
- if ((cgroup_task_count(cur->css.cgroup) || cur->attach_in_progress) &&
- (cpumask_empty(trial->cpus_allowed) &&
- nodes_empty(trial->mems_allowed)))
- goto out;
+ if ((cgroup_task_count(cur->css.cgroup) || cur->attach_in_progress)) {
+ if (!cpumask_empty(cur->cpus_allowed) &&
+ cpumask_empty(trial->cpus_allowed))
+ goto out;
+ if (!nodes_empty(cur->mems_allowed) &&
+ nodes_empty(trial->mems_allowed))
+ goto out;
+ }
ret = 0;
out:
@@ -1608,11 +1612,13 @@ static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val)
{
struct cpuset *cs = cgroup_cs(cgrp);
cpuset_filetype_t type = cft->private;
- int retval = -ENODEV;
+ int retval = 0;
mutex_lock(&cpuset_mutex);
- if (!is_cpuset_online(cs))
+ if (!is_cpuset_online(cs)) {
+ retval = -ENODEV;
goto out_unlock;
+ }
switch (type) {
case FILE_CPU_EXCLUSIVE:
diff --git a/kernel/fork.c b/kernel/fork.c
index 403d2bb8a96..bf46287c91a 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1177,7 +1177,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
* don't allow the creation of threads.
*/
if ((clone_flags & (CLONE_VM|CLONE_NEWPID)) &&
- (task_active_pid_ns(current) != current->nsproxy->pid_ns))
+ (task_active_pid_ns(current) !=
+ current->nsproxy->pid_ns_for_children))
return ERR_PTR(-EINVAL);
retval = security_task_create(clone_flags);
@@ -1351,7 +1352,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
if (pid != &init_struct_pid) {
retval = -ENOMEM;
- pid = alloc_pid(p->nsproxy->pid_ns);
+ pid = alloc_pid(p->nsproxy->pid_ns_for_children);
if (!pid)
goto bad_fork_cleanup_io;
}
@@ -1679,6 +1680,12 @@ SYSCALL_DEFINE5(clone, unsigned long, newsp, unsigned long, clone_flags,
int __user *, parent_tidptr,
int __user *, child_tidptr,
int, tls_val)
+#elif defined(CONFIG_CLONE_BACKWARDS3)
+SYSCALL_DEFINE6(clone, unsigned long, clone_flags, unsigned long, newsp,
+ int, stack_size,
+ int __user *, parent_tidptr,
+ int __user *, child_tidptr,
+ int, tls_val)
#else
SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
int __user *, parent_tidptr,
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index 364ceab15f0..997cbb951a3 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -29,15 +29,15 @@
static struct kmem_cache *nsproxy_cachep;
struct nsproxy init_nsproxy = {
- .count = ATOMIC_INIT(1),
- .uts_ns = &init_uts_ns,
+ .count = ATOMIC_INIT(1),
+ .uts_ns = &init_uts_ns,
#if defined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC)
- .ipc_ns = &init_ipc_ns,
+ .ipc_ns = &init_ipc_ns,
#endif
- .mnt_ns = NULL,
- .pid_ns = &init_pid_ns,
+ .mnt_ns = NULL,
+ .pid_ns_for_children = &init_pid_ns,
#ifdef CONFIG_NET
- .net_ns = &init_net,
+ .net_ns = &init_net,
#endif
};
@@ -85,9 +85,10 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
goto out_ipc;
}
- new_nsp->pid_ns = copy_pid_ns(flags, user_ns, tsk->nsproxy->pid_ns);
- if (IS_ERR(new_nsp->pid_ns)) {
- err = PTR_ERR(new_nsp->pid_ns);
+ new_nsp->pid_ns_for_children =
+ copy_pid_ns(flags, user_ns, tsk->nsproxy->pid_ns_for_children);
+ if (IS_ERR(new_nsp->pid_ns_for_children)) {
+ err = PTR_ERR(new_nsp->pid_ns_for_children);
goto out_pid;
}
@@ -100,8 +101,8 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
return new_nsp;
out_net:
- if (new_nsp->pid_ns)
- put_pid_ns(new_nsp->pid_ns);
+ if (new_nsp->pid_ns_for_children)
+ put_pid_ns(new_nsp->pid_ns_for_children);
out_pid:
if (new_nsp->ipc_ns)
put_ipc_ns(new_nsp->ipc_ns);
@@ -174,8 +175,8 @@ void free_nsproxy(struct nsproxy *ns)
put_uts_ns(ns->uts_ns);
if (ns->ipc_ns)
put_ipc_ns(ns->ipc_ns);
- if (ns->pid_ns)
- put_pid_ns(ns->pid_ns);
+ if (ns->pid_ns_for_children)
+ put_pid_ns(ns->pid_ns_for_children);
put_net(ns->net_ns);
kmem_cache_free(nsproxy_cachep, ns);
}
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index 6917e8edb48..601bb361c23 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -349,8 +349,8 @@ static int pidns_install(struct nsproxy *nsproxy, void *ns)
if (ancestor != active)
return -EINVAL;
- put_pid_ns(nsproxy->pid_ns);
- nsproxy->pid_ns = get_pid_ns(new);
+ put_pid_ns(nsproxy->pid_ns_for_children);
+ nsproxy->pid_ns_for_children = get_pid_ns(new);
return 0;
}
diff --git a/kernel/power/qos.c b/kernel/power/qos.c
index 06fe28589e9..a394297f8b2 100644
--- a/kernel/power/qos.c
+++ b/kernel/power/qos.c
@@ -296,6 +296,17 @@ int pm_qos_request_active(struct pm_qos_request *req)
}
EXPORT_SYMBOL_GPL(pm_qos_request_active);
+static void __pm_qos_update_request(struct pm_qos_request *req,
+ s32 new_value)
+{
+ trace_pm_qos_update_request(req->pm_qos_class, new_value);
+
+ if (new_value != req->node.prio)
+ pm_qos_update_target(
+ pm_qos_array[req->pm_qos_class]->constraints,
+ &req->node, PM_QOS_UPDATE_REQ, new_value);
+}
+
/**
* pm_qos_work_fn - the timeout handler of pm_qos_update_request_timeout
* @work: work struct for the delayed work (timeout)
@@ -308,7 +319,7 @@ static void pm_qos_work_fn(struct work_struct *work)
struct pm_qos_request,
work);
- pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE);
+ __pm_qos_update_request(req, PM_QOS_DEFAULT_VALUE);
}
/**
@@ -364,12 +375,7 @@ void pm_qos_update_request(struct pm_qos_request *req,
}
cancel_delayed_work_sync(&req->work);
-
- trace_pm_qos_update_request(req->pm_qos_class, new_value);
- if (new_value != req->node.prio)
- pm_qos_update_target(
- pm_qos_array[req->pm_qos_class]->constraints,
- &req->node, PM_QOS_UPDATE_REQ, new_value);
+ __pm_qos_update_request(req, new_value);
}
EXPORT_SYMBOL_GPL(pm_qos_update_request);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index b7c32cb7bfe..05c39f03031 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -933,6 +933,8 @@ static int effective_prio(struct task_struct *p)
/**
* task_curr - is this task currently executing on a CPU?
* @p: the task in question.
+ *
+ * Return: 1 if the task is currently executing. 0 otherwise.
*/
inline int task_curr(const struct task_struct *p)
{
@@ -1482,7 +1484,7 @@ static void ttwu_queue(struct task_struct *p, int cpu)
* the simpler "current->state = TASK_RUNNING" to mark yourself
* runnable without the overhead of this.
*
- * Returns %true if @p was woken up, %false if it was already running
+ * Return: %true if @p was woken up, %false if it was already running.
* or @state didn't match @p's state.
*/
static int
@@ -1491,7 +1493,13 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
unsigned long flags;
int cpu, success = 0;
- smp_wmb();
+ /*
+ * If we are going to wake up a thread waiting for CONDITION we
+ * need to ensure that CONDITION=1 done by the caller can not be
+ * reordered with p->state check below. This pairs with mb() in
+ * set_current_state() the waiting thread does.
+ */
+ smp_mb__before_spinlock();
raw_spin_lock_irqsave(&p->pi_lock, flags);
if (!(p->state & state))
goto out;
@@ -1577,8 +1585,9 @@ out:
* @p: The process to be woken up.
*
* Attempt to wake up the nominated process and move it to the set of runnable
- * processes. Returns 1 if the process was woken up, 0 if it was already
- * running.
+ * processes.
+ *
+ * Return: 1 if the process was woken up, 0 if it was already running.
*
* It may be assumed that this function implies a write memory barrier before
* changing the task state if and only if any tasks are woken up.
@@ -2191,6 +2200,8 @@ void scheduler_tick(void)
* This makes sure that uptime, CFS vruntime, load
* balancing, etc... continue to move forward, even
* with a very low granularity.
+ *
+ * Return: Maximum deferment in nanoseconds.
*/
u64 scheduler_tick_max_deferment(void)
{
@@ -2394,6 +2405,12 @@ need_resched:
if (sched_feat(HRTICK))
hrtick_clear(rq);
+ /*
+ * Make sure that signal_pending_state()->signal_pending() below
+ * can't be reordered with __set_current_state(TASK_INTERRUPTIBLE)
+ * done by the caller to avoid the race with signal_wake_up().
+ */
+ smp_mb__before_spinlock();
raw_spin_lock_irq(&rq->lock);
switch_count = &prev->nivcsw;
@@ -2796,8 +2813,8 @@ EXPORT_SYMBOL(wait_for_completion);
* specified timeout to expire. The timeout is in jiffies. It is not
* interruptible.
*
- * The return value is 0 if timed out, and positive (at least 1, or number of
- * jiffies left till timeout) if completed.
+ * Return: 0 if timed out, and positive (at least 1, or number of jiffies left
+ * till timeout) if completed.
*/
unsigned long __sched
wait_for_completion_timeout(struct completion *x, unsigned long timeout)
@@ -2829,8 +2846,8 @@ EXPORT_SYMBOL(wait_for_completion_io);
* specified timeout to expire. The timeout is in jiffies. It is not
* interruptible. The caller is accounted as waiting for IO.
*
- * The return value is 0 if timed out, and positive (at least 1, or number of
- * jiffies left till timeout) if completed.
+ * Return: 0 if timed out, and positive (at least 1, or number of jiffies left
+ * till timeout) if completed.
*/
unsigned long __sched
wait_for_completion_io_timeout(struct completion *x, unsigned long timeout)
@@ -2846,7 +2863,7 @@ EXPORT_SYMBOL(wait_for_completion_io_timeout);
* This waits for completion of a specific task to be signaled. It is
* interruptible.
*
- * The return value is -ERESTARTSYS if interrupted, 0 if completed.
+ * Return: -ERESTARTSYS if interrupted, 0 if completed.
*/
int __sched wait_for_completion_interruptible(struct completion *x)
{
@@ -2865,8 +2882,8 @@ EXPORT_SYMBOL(wait_for_completion_interruptible);
* This waits for either a completion of a specific task to be signaled or for a
* specified timeout to expire. It is interruptible. The timeout is in jiffies.
*
- * The return value is -ERESTARTSYS if interrupted, 0 if timed out,
- * positive (at least 1, or number of jiffies left till timeout) if completed.
+ * Return: -ERESTARTSYS if interrupted, 0 if timed out, positive (at least 1,
+ * or number of jiffies left till timeout) if completed.
*/
long __sched
wait_for_completion_interruptible_timeout(struct completion *x,
@@ -2883,7 +2900,7 @@ EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
* This waits to be signaled for completion of a specific task. It can be
* interrupted by a kill signal.
*
- * The return value is -ERESTARTSYS if interrupted, 0 if completed.
+ * Return: -ERESTARTSYS if interrupted, 0 if completed.
*/
int __sched wait_for_completion_killable(struct completion *x)
{
@@ -2903,8 +2920,8 @@ EXPORT_SYMBOL(wait_for_completion_killable);
* signaled or for a specified timeout to expire. It can be
* interrupted by a kill signal. The timeout is in jiffies.
*
- * The return value is -ERESTARTSYS if interrupted, 0 if timed out,
- * positive (at least 1, or number of jiffies left till timeout) if completed.
+ * Return: -ERESTARTSYS if interrupted, 0 if timed out, positive (at least 1,
+ * or number of jiffies left till timeout) if completed.
*/
long __sched
wait_for_completion_killable_timeout(struct completion *x,
@@ -2918,7 +2935,7 @@ EXPORT_SYMBOL(wait_for_completion_killable_timeout);
* try_wait_for_completion - try to decrement a completion without blocking
* @x: completion structure
*
- * Returns: 0 if a decrement cannot be done without blocking
+ * Return: 0 if a decrement cannot be done without blocking
* 1 if a decrement succeeded.
*
* If a completion is being used as a counting completion,
@@ -2945,7 +2962,7 @@ EXPORT_SYMBOL(try_wait_for_completion);
* completion_done - Test to see if a completion has any waiters
* @x: completion structure
*
- * Returns: 0 if there are waiters (wait_for_completion() in progress)
+ * Return: 0 if there are waiters (wait_for_completion() in progress)
* 1 if there are no waiters.
*
*/
@@ -3182,7 +3199,7 @@ SYSCALL_DEFINE1(nice, int, increment)
* task_prio - return the priority value of a given task.
* @p: the task in question.
*
- * This is the priority value as seen by users in /proc.
+ * Return: The priority value as seen by users in /proc.
* RT tasks are offset by -200. Normal tasks are centered
* around 0, value goes from -16 to +15.
*/
@@ -3194,6 +3211,8 @@ int task_prio(const struct task_struct *p)
/**
* task_nice - return the nice value of a given task.
* @p: the task in question.
+ *
+ * Return: The nice value [ -20 ... 0 ... 19 ].
*/
int task_nice(const struct task_struct *p)
{
@@ -3204,6 +3223,8 @@ EXPORT_SYMBOL(task_nice);
/**
* idle_cpu - is a given cpu idle currently?
* @cpu: the processor in question.
+ *
+ * Return: 1 if the CPU is currently idle. 0 otherwise.
*/
int idle_cpu(int cpu)
{
@@ -3226,6 +3247,8 @@ int idle_cpu(int cpu)
/**
* idle_task - return the idle task for a given cpu.
* @cpu: the processor in question.
+ *
+ * Return: The idle task for the cpu @cpu.
*/
struct task_struct *idle_task(int cpu)
{
@@ -3235,6 +3258,8 @@ struct task_struct *idle_task(int cpu)
/**
* find_process_by_pid - find a process with a matching PID value.
* @pid: the pid in question.
+ *
+ * The task of @pid, if found. %NULL otherwise.
*/
static struct task_struct *find_process_by_pid(pid_t pid)
{
@@ -3432,6 +3457,8 @@ recheck:
* @policy: new policy.
* @param: structure containing the new RT priority.
*
+ * Return: 0 on success. An error code otherwise.
+ *
* NOTE that the task may be already dead.
*/
int sched_setscheduler(struct task_struct *p, int policy,
@@ -3451,6 +3478,8 @@ EXPORT_SYMBOL_GPL(sched_setscheduler);
* current context has permission. For example, this is needed in
* stop_machine(): we create temporary high priority worker threads,
* but our caller might not have that capability.
+ *
+ * Return: 0 on success. An error code otherwise.
*/
int sched_setscheduler_nocheck(struct task_struct *p, int policy,
const struct sched_param *param)
@@ -3485,6 +3514,8 @@ do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param)
* @pid: the pid in question.
* @policy: new policy.
* @param: structure containing the new RT priority.
+ *
+ * Return: 0 on success. An error code otherwise.
*/
SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy,
struct sched_param __user *, param)
@@ -3500,6 +3531,8 @@ SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy,
* sys_sched_setparam - set/change the RT priority of a thread
* @pid: the pid in question.
* @param: structure containing the new RT priority.
+ *
+ * Return: 0 on success. An error code otherwise.
*/
SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param)
{
@@ -3509,6 +3542,9 @@ SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param)
/**
* sys_sched_getscheduler - get the policy (scheduling class) of a thread
* @pid: the pid in question.
+ *
+ * Return: On success, the policy of the thread. Otherwise, a negative error
+ * code.
*/
SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
{
@@ -3535,6 +3571,9 @@ SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
* sys_sched_getparam - get the RT priority of a thread
* @pid: the pid in question.
* @param: structure containing the RT priority.
+ *
+ * Return: On success, 0 and the RT priority is in @param. Otherwise, an error
+ * code.
*/
SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
{
@@ -3659,6 +3698,8 @@ static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len,
* @pid: pid of the process
* @len: length in bytes of the bitmask pointed to by user_mask_ptr
* @user_mask_ptr: user-space pointer to the new cpu mask
+ *
+ * Return: 0 on success. An error code otherwise.
*/
SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len,
unsigned long __user *, user_mask_ptr)
@@ -3710,6 +3751,8 @@ out_unlock:
* @pid: pid of the process
* @len: length in bytes of the bitmask pointed to by user_mask_ptr
* @user_mask_ptr: user-space pointer to hold the current cpu mask
+ *
+ * Return: 0 on success. An error code otherwise.
*/
SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
unsigned long __user *, user_mask_ptr)
@@ -3744,6 +3787,8 @@ SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
*
* This function yields the current CPU to other tasks. If there are no
* other threads running on this CPU then this function will return.
+ *
+ * Return: 0.
*/
SYSCALL_DEFINE0(sched_yield)
{
@@ -3869,7 +3914,7 @@ EXPORT_SYMBOL(yield);
* It's the caller's job to ensure that the target task struct
* can't go away on us before we can do any checks.
*
- * Returns:
+ * Return:
* true (>0) if we indeed boosted the target task.
* false (0) if we failed to boost the target.
* -ESRCH if there's no task to yield to.
@@ -3972,8 +4017,9 @@ long __sched io_schedule_timeout(long timeout)
* sys_sched_get_priority_max - return maximum RT priority.
* @policy: scheduling class.
*
- * this syscall returns the maximum rt_priority that can be used
- * by a given scheduling class.
+ * Return: On success, this syscall returns the maximum
+ * rt_priority that can be used by a given scheduling class.
+ * On failure, a negative error code is returned.
*/
SYSCALL_DEFINE1(sched_get_priority_max, int, policy)
{
@@ -3997,8 +4043,9 @@ SYSCALL_DEFINE1(sched_get_priority_max, int, policy)
* sys_sched_get_priority_min - return minimum RT priority.
* @policy: scheduling class.
*
- * this syscall returns the minimum rt_priority that can be used
- * by a given scheduling class.
+ * Return: On success, this syscall returns the minimum
+ * rt_priority that can be used by a given scheduling class.
+ * On failure, a negative error code is returned.
*/
SYSCALL_DEFINE1(sched_get_priority_min, int, policy)
{
@@ -4024,6 +4071,9 @@ SYSCALL_DEFINE1(sched_get_priority_min, int, policy)
*
* this syscall writes the default timeslice value of a given process
* into the user-space timespec buffer. A value of '0' means infinity.
+ *
+ * Return: On success, 0 and the timeslice is in @interval. Otherwise,
+ * an error code.
*/
SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
struct timespec __user *, interval)
@@ -6632,6 +6682,8 @@ void normalize_rt_tasks(void)
* @cpu: the processor in question.
*
* ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
+ *
+ * Return: The current task for @cpu.
*/
struct task_struct *curr_task(int cpu)
{
diff --git a/kernel/sched/cpupri.c b/kernel/sched/cpupri.c
index 1095e878a46..8b836b376d9 100644
--- a/kernel/sched/cpupri.c
+++ b/kernel/sched/cpupri.c
@@ -62,7 +62,7 @@ static int convert_prio(int prio)
* any discrepancies created by racing against the uncertainty of the current
* priority configuration.
*
- * Returns: (int)bool - CPUs were found
+ * Return: (int)bool - CPUs were found
*/
int cpupri_find(struct cpupri *cp, struct task_struct *p,
struct cpumask *lowest_mask)
@@ -203,7 +203,7 @@ void cpupri_set(struct cpupri *cp, int cpu, int newpri)
* cpupri_init - initialize the cpupri structure
* @cp: The cpupri context
*
- * Returns: -ENOMEM if memory fails.
+ * Return: -ENOMEM on memory allocation failure.
*/
int cpupri_init(struct cpupri *cp)
{
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 9565645e320..68f1609ca14 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2032,6 +2032,7 @@ entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued)
*/
update_entity_load_avg(curr, 1);
update_cfs_rq_blocked_load(cfs_rq, 1);
+ update_cfs_shares(cfs_rq);
#ifdef CONFIG_SCHED_HRTICK
/*
@@ -4280,6 +4281,8 @@ struct sg_lb_stats {
* get_sd_load_idx - Obtain the load index for a given sched domain.
* @sd: The sched_domain whose load_idx is to be obtained.
* @idle: The Idle status of the CPU for whose sd load_icx is obtained.
+ *
+ * Return: The load index.
*/
static inline int get_sd_load_idx(struct sched_domain *sd,
enum cpu_idle_type idle)
@@ -4574,6 +4577,9 @@ static inline void update_sg_lb_stats(struct lb_env *env,
*
* Determine if @sg is a busier group than the previously selected
* busiest group.
+ *
+ * Return: %true if @sg is a busier group than the previously selected
+ * busiest group. %false otherwise.
*/
static bool update_sd_pick_busiest(struct lb_env *env,
struct sd_lb_stats *sds,
@@ -4691,7 +4697,7 @@ static inline void update_sd_lb_stats(struct lb_env *env,
* assuming lower CPU number will be equivalent to lower a SMT thread
* number.
*
- * Returns 1 when packing is required and a task should be moved to
+ * Return: 1 when packing is required and a task should be moved to
* this CPU. The amount of the imbalance is returned in *imbalance.
*
* @env: The load balancing environment.
@@ -4869,7 +4875,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
* @balance: Pointer to a variable indicating if this_cpu
* is the appropriate cpu to perform load balancing at this_level.
*
- * Returns: - the busiest group if imbalance exists.
+ * Return: - The busiest group if imbalance exists.
* - If no imbalance and user has opted for power-savings balance,
* return the least loaded group whose CPUs can be
* put to idle by rebalancing its tasks onto our group.
diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c
index a326f27d7f0..0b479a6a22b 100644
--- a/kernel/time/sched_clock.c
+++ b/kernel/time/sched_clock.c
@@ -121,7 +121,7 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate)
BUG_ON(bits > 32);
WARN_ON(!irqs_disabled());
read_sched_clock = read;
- sched_clock_mask = (1 << bits) - 1;
+ sched_clock_mask = (1ULL << bits) - 1;
cd.rate = rate;
/* calculate the mult/shift to convert counter ticks to ns. */
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index e77edc97e03..e8a1516cc0a 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -182,7 +182,8 @@ static bool can_stop_full_tick(void)
* Don't allow the user to think they can get
* full NO_HZ with this machine.
*/
- WARN_ONCE(1, "NO_HZ FULL will not work with unstable sched clock");
+ WARN_ONCE(have_nohz_full_mask,
+ "NO_HZ FULL will not work with unstable sched clock");
return false;
}
#endif
@@ -343,8 +344,6 @@ static int tick_nohz_init_all(void)
void __init tick_nohz_init(void)
{
- int cpu;
-
if (!have_nohz_full_mask) {
if (tick_nohz_init_all() < 0)
return;
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index 3bdf2832301..61ed862cdd3 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -265,10 +265,9 @@ static inline void timer_list_header(struct seq_file *m, u64 now)
static int timer_list_show(struct seq_file *m, void *v)
{
struct timer_list_iter *iter = v;
- u64 now = ktime_to_ns(ktime_get());
if (iter->cpu == -1 && !iter->second_pass)
- timer_list_header(m, now);
+ timer_list_header(m, iter->now);
else if (!iter->second_pass)
print_cpu(m, iter->cpu, iter->now);
#ifdef CONFIG_GENERIC_CLOCKEVENTS
@@ -298,33 +297,41 @@ void sysrq_timer_list_show(void)
return;
}
-static void *timer_list_start(struct seq_file *file, loff_t *offset)
+static void *move_iter(struct timer_list_iter *iter, loff_t offset)
{
- struct timer_list_iter *iter = file->private;
-
- if (!*offset) {
- iter->cpu = -1;
- iter->now = ktime_to_ns(ktime_get());
- } else if (iter->cpu >= nr_cpu_ids) {
+ for (; offset; offset--) {
+ iter->cpu = cpumask_next(iter->cpu, cpu_online_mask);
+ if (iter->cpu >= nr_cpu_ids) {
#ifdef CONFIG_GENERIC_CLOCKEVENTS
- if (!iter->second_pass) {
- iter->cpu = -1;
- iter->second_pass = true;
- } else
- return NULL;
+ if (!iter->second_pass) {
+ iter->cpu = -1;
+ iter->second_pass = true;
+ } else
+ return NULL;
#else
- return NULL;
+ return NULL;
#endif
+ }
}
return iter;
}
+static void *timer_list_start(struct seq_file *file, loff_t *offset)
+{
+ struct timer_list_iter *iter = file->private;
+
+ if (!*offset)
+ iter->now = ktime_to_ns(ktime_get());
+ iter->cpu = -1;
+ iter->second_pass = false;
+ return move_iter(iter, *offset);
+}
+
static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset)
{
struct timer_list_iter *iter = file->private;
- iter->cpu = cpumask_next(iter->cpu, cpu_online_mask);
++*offset;
- return timer_list_start(file, offset);
+ return move_iter(iter, 1);
}
static void timer_list_stop(struct seq_file *seq, void *v)
diff --git a/kernel/wait.c b/kernel/wait.c
index dec68bd4e9d..d550920e040 100644
--- a/kernel/wait.c
+++ b/kernel/wait.c
@@ -363,8 +363,7 @@ EXPORT_SYMBOL(out_of_line_wait_on_atomic_t);
/**
* wake_up_atomic_t - Wake up a waiter on a atomic_t
- * @word: The word being waited on, a kernel virtual address
- * @bit: The bit of the word being waited on
+ * @p: The atomic_t being waited on, a kernel virtual address
*
* Wake up anyone waiting for the atomic_t to go to zero.
*
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 7f5d4be2203..e93f7b9067d 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2201,6 +2201,15 @@ __acquires(&pool->lock)
dump_stack();
}
+ /*
+ * The following prevents a kworker from hogging CPU on !PREEMPT
+ * kernels, where a requeueing work item waiting for something to
+ * happen could deadlock with stop_machine as such work item could
+ * indefinitely requeue itself while all other CPUs are trapped in
+ * stop_machine.
+ */
+ cond_resched();
+
spin_lock_irq(&pool->lock);
/* clear cpu intensive status */
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-11-25 22:12:47 +0000