summaryrefslogtreecommitdiffstats
path: root/kernel
diff options
context:
space:
mode:
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup.c110
-rw-r--r--kernel/fork.c4
-rw-r--r--kernel/irq/chip.c33
-rw-r--r--kernel/irq/handle.c4
-rw-r--r--kernel/irq/internals.h2
-rw-r--r--kernel/irq/irqdesc.c20
-rw-r--r--kernel/irq/irqdomain.c1
-rw-r--r--kernel/irq/manage.c12
-rw-r--r--kernel/irq/proc.c2
-rw-r--r--kernel/irq/resend.c2
-rw-r--r--kernel/locking/qspinlock.c2
-rw-r--r--kernel/sched/core.c51
-rw-r--r--kernel/sched/wait.c7
-rw-r--r--kernel/time/clockevents.c42
-rw-r--r--kernel/time/tick-common.c1
-rw-r--r--kernel/time/tick-sched.c15
-rw-r--r--kernel/time/timekeeping.c2
-rw-r--r--kernel/time/timer_list.c54
18 files changed, 206 insertions, 158 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 2cf0f79f1fc9..2c9eae6ad970 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -46,7 +46,6 @@
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/rwsem.h>
-#include <linux/percpu-rwsem.h>
#include <linux/string.h>
#include <linux/sort.h>
#include <linux/kmod.h>
@@ -104,8 +103,6 @@ static DEFINE_SPINLOCK(cgroup_idr_lock);
*/
static DEFINE_SPINLOCK(release_agent_path_lock);
-struct percpu_rw_semaphore cgroup_threadgroup_rwsem;
-
#define cgroup_assert_mutex_or_rcu_locked() \
RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \
!lockdep_is_held(&cgroup_mutex), \
@@ -874,6 +871,48 @@ static struct css_set *find_css_set(struct css_set *old_cset,
return cset;
}
+void cgroup_threadgroup_change_begin(struct task_struct *tsk)
+{
+ down_read(&tsk->signal->group_rwsem);
+}
+
+void cgroup_threadgroup_change_end(struct task_struct *tsk)
+{
+ up_read(&tsk->signal->group_rwsem);
+}
+
+/**
+ * threadgroup_lock - lock threadgroup
+ * @tsk: member task of the threadgroup to lock
+ *
+ * Lock the threadgroup @tsk belongs to. No new task is allowed to enter
+ * and member tasks aren't allowed to exit (as indicated by PF_EXITING) or
+ * change ->group_leader/pid. This is useful for cases where the threadgroup
+ * needs to stay stable across blockable operations.
+ *
+ * fork and exit explicitly call threadgroup_change_{begin|end}() for
+ * synchronization. While held, no new task will be added to threadgroup
+ * and no existing live task will have its PF_EXITING set.
+ *
+ * de_thread() does threadgroup_change_{begin|end}() when a non-leader
+ * sub-thread becomes a new leader.
+ */
+static void threadgroup_lock(struct task_struct *tsk)
+{
+ down_write(&tsk->signal->group_rwsem);
+}
+
+/**
+ * threadgroup_unlock - unlock threadgroup
+ * @tsk: member task of the threadgroup to unlock
+ *
+ * Reverse threadgroup_lock().
+ */
+static inline void threadgroup_unlock(struct task_struct *tsk)
+{
+ up_write(&tsk->signal->group_rwsem);
+}
+
static struct cgroup_root *cgroup_root_from_kf(struct kernfs_root *kf_root)
{
struct cgroup *root_cgrp = kf_root->kn->priv;
@@ -2074,9 +2113,9 @@ static void cgroup_task_migrate(struct cgroup *old_cgrp,
lockdep_assert_held(&css_set_rwsem);
/*
- * We are synchronized through cgroup_threadgroup_rwsem against
- * PF_EXITING setting such that we can't race against cgroup_exit()
- * changing the css_set to init_css_set and dropping the old one.
+ * We are synchronized through threadgroup_lock() against PF_EXITING
+ * setting such that we can't race against cgroup_exit() changing the
+ * css_set to init_css_set and dropping the old one.
*/
WARN_ON_ONCE(tsk->flags & PF_EXITING);
old_cset = task_css_set(tsk);
@@ -2133,11 +2172,10 @@ static void cgroup_migrate_finish(struct list_head *preloaded_csets)
* @src_cset and add it to @preloaded_csets, which should later be cleaned
* up by cgroup_migrate_finish().
*
- * This function may be called without holding cgroup_threadgroup_rwsem
- * even if the target is a process. Threads may be created and destroyed
- * but as long as cgroup_mutex is not dropped, no new css_set can be put
- * into play and the preloaded css_sets are guaranteed to cover all
- * migrations.
+ * This function may be called without holding threadgroup_lock even if the
+ * target is a process. Threads may be created and destroyed but as long
+ * as cgroup_mutex is not dropped, no new css_set can be put into play and
+ * the preloaded css_sets are guaranteed to cover all migrations.
*/
static void cgroup_migrate_add_src(struct css_set *src_cset,
struct cgroup *dst_cgrp,
@@ -2240,7 +2278,7 @@ err:
* @threadgroup: whether @leader points to the whole process or a single task
*
* Migrate a process or task denoted by @leader to @cgrp. If migrating a
- * process, the caller must be holding cgroup_threadgroup_rwsem. The
+ * process, the caller must be holding threadgroup_lock of @leader. The
* caller is also responsible for invoking cgroup_migrate_add_src() and
* cgroup_migrate_prepare_dst() on the targets before invoking this
* function and following up with cgroup_migrate_finish().
@@ -2368,7 +2406,7 @@ out_release_tset:
* @leader: the task or the leader of the threadgroup to be attached
* @threadgroup: attach the whole threadgroup?
*
- * Call holding cgroup_mutex and cgroup_threadgroup_rwsem.
+ * Call holding cgroup_mutex and threadgroup_lock of @leader.
*/
static int cgroup_attach_task(struct cgroup *dst_cgrp,
struct task_struct *leader, bool threadgroup)
@@ -2460,13 +2498,14 @@ static ssize_t __cgroup_procs_write(struct kernfs_open_file *of, char *buf,
if (!cgrp)
return -ENODEV;
- percpu_down_write(&cgroup_threadgroup_rwsem);
+retry_find_task:
rcu_read_lock();
if (pid) {
tsk = find_task_by_vpid(pid);
if (!tsk) {
+ rcu_read_unlock();
ret = -ESRCH;
- goto out_unlock_rcu;
+ goto out_unlock_cgroup;
}
} else {
tsk = current;
@@ -2482,23 +2521,37 @@ static ssize_t __cgroup_procs_write(struct kernfs_open_file *of, char *buf,
*/
if (tsk == kthreadd_task || (tsk->flags & PF_NO_SETAFFINITY)) {
ret = -EINVAL;
- goto out_unlock_rcu;
+ rcu_read_unlock();
+ goto out_unlock_cgroup;
}
get_task_struct(tsk);
rcu_read_unlock();
+ threadgroup_lock(tsk);
+ if (threadgroup) {
+ if (!thread_group_leader(tsk)) {
+ /*
+ * a race with de_thread from another thread's exec()
+ * may strip us of our leadership, if this happens,
+ * there is no choice but to throw this task away and
+ * try again; this is
+ * "double-double-toil-and-trouble-check locking".
+ */
+ threadgroup_unlock(tsk);
+ put_task_struct(tsk);
+ goto retry_find_task;
+ }
+ }
+
ret = cgroup_procs_write_permission(tsk, cgrp, of);
if (!ret)
ret = cgroup_attach_task(cgrp, tsk, threadgroup);
- put_task_struct(tsk);
- goto out_unlock_threadgroup;
+ threadgroup_unlock(tsk);
-out_unlock_rcu:
- rcu_read_unlock();
-out_unlock_threadgroup:
- percpu_up_write(&cgroup_threadgroup_rwsem);
+ put_task_struct(tsk);
+out_unlock_cgroup:
cgroup_kn_unlock(of->kn);
return ret ?: nbytes;
}
@@ -2643,8 +2696,6 @@ static int cgroup_update_dfl_csses(struct cgroup *cgrp)
lockdep_assert_held(&cgroup_mutex);
- percpu_down_write(&cgroup_threadgroup_rwsem);
-
/* look up all csses currently attached to @cgrp's subtree */
down_read(&css_set_rwsem);
css_for_each_descendant_pre(css, cgroup_css(cgrp, NULL)) {
@@ -2700,8 +2751,17 @@ static int cgroup_update_dfl_csses(struct cgroup *cgrp)
goto out_finish;
last_task = task;
+ threadgroup_lock(task);
+ /* raced against de_thread() from another thread? */
+ if (!thread_group_leader(task)) {
+ threadgroup_unlock(task);
+ put_task_struct(task);
+ continue;
+ }
+
ret = cgroup_migrate(src_cset->dfl_cgrp, task, true);
+ threadgroup_unlock(task);
put_task_struct(task);
if (WARN(ret, "cgroup: failed to update controllers for the default hierarchy (%d), further operations may crash or hang\n", ret))
@@ -2711,7 +2771,6 @@ static int cgroup_update_dfl_csses(struct cgroup *cgrp)
out_finish:
cgroup_migrate_finish(&preloaded_csets);
- percpu_up_write(&cgroup_threadgroup_rwsem);
return ret;
}
@@ -5024,7 +5083,6 @@ int __init cgroup_init(void)
unsigned long key;
int ssid, err;
- BUG_ON(percpu_init_rwsem(&cgroup_threadgroup_rwsem));
BUG_ON(cgroup_init_cftypes(NULL, cgroup_dfl_base_files));
BUG_ON(cgroup_init_cftypes(NULL, cgroup_legacy_base_files));
diff --git a/kernel/fork.c b/kernel/fork.c
index 7d5f0f118a63..2845623fb582 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1149,6 +1149,10 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
tty_audit_fork(sig);
sched_autogroup_fork(sig);
+#ifdef CONFIG_CGROUPS
+ init_rwsem(&sig->group_rwsem);
+#endif
+
sig->oom_score_adj = current->signal->oom_score_adj;
sig->oom_score_adj_min = current->signal->oom_score_adj_min;
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 6e40a9539763..e28169dd1c36 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -83,7 +83,7 @@ int irq_set_handler_data(unsigned int irq, void *data)
if (!desc)
return -EINVAL;
- desc->irq_data.handler_data = data;
+ desc->irq_common_data.handler_data = data;
irq_put_desc_unlock(desc, flags);
return 0;
}
@@ -105,7 +105,7 @@ int irq_set_msi_desc_off(unsigned int irq_base, unsigned int irq_offset,
if (!desc)
return -EINVAL;
- desc->irq_data.msi_desc = entry;
+ desc->irq_common_data.msi_desc = entry;
if (entry && !irq_offset)
entry->irq = irq_base;
irq_put_desc_unlock(desc, flags);
@@ -372,7 +372,6 @@ static bool irq_may_run(struct irq_desc *desc)
/**
* handle_simple_irq - Simple and software-decoded IRQs.
- * @irq: the interrupt number
* @desc: the interrupt description structure for this irq
*
* Simple interrupts are either sent from a demultiplexing interrupt
@@ -382,8 +381,7 @@ static bool irq_may_run(struct irq_desc *desc)
* Note: The caller is expected to handle the ack, clear, mask and
* unmask issues if necessary.
*/
-void
-handle_simple_irq(unsigned int irq, struct irq_desc *desc)
+void handle_simple_irq(struct irq_desc *desc)
{
raw_spin_lock(&desc->lock);
@@ -425,7 +423,6 @@ static void cond_unmask_irq(struct irq_desc *desc)
/**
* handle_level_irq - Level type irq handler
- * @irq: the interrupt number
* @desc: the interrupt description structure for this irq
*
* Level type interrupts are active as long as the hardware line has
@@ -433,8 +430,7 @@ static void cond_unmask_irq(struct irq_desc *desc)
* it after the associated handler has acknowledged the device, so the
* interrupt line is back to inactive.
*/
-void
-handle_level_irq(unsigned int irq, struct irq_desc *desc)
+void handle_level_irq(struct irq_desc *desc)
{
raw_spin_lock(&desc->lock);
mask_ack_irq(desc);
@@ -496,7 +492,6 @@ static void cond_unmask_eoi_irq(struct irq_desc *desc, struct irq_chip *chip)
/**
* handle_fasteoi_irq - irq handler for transparent controllers
- * @irq: the interrupt number
* @desc: the interrupt description structure for this irq
*
* Only a single callback will be issued to the chip: an ->eoi()
@@ -504,8 +499,7 @@ static void cond_unmask_eoi_irq(struct irq_desc *desc, struct irq_chip *chip)
* for modern forms of interrupt handlers, which handle the flow
* details in hardware, transparently.
*/
-void
-handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
+void handle_fasteoi_irq(struct irq_desc *desc)
{
struct irq_chip *chip = desc->irq_data.chip;
@@ -546,7 +540,6 @@ EXPORT_SYMBOL_GPL(handle_fasteoi_irq);
/**
* handle_edge_irq - edge type IRQ handler
- * @irq: the interrupt number
* @desc: the interrupt description structure for this irq
*
* Interrupt occures on the falling and/or rising edge of a hardware
@@ -560,8 +553,7 @@ EXPORT_SYMBOL_GPL(handle_fasteoi_irq);
* the handler was running. If all pending interrupts are handled, the
* loop is left.
*/
-void
-handle_edge_irq(unsigned int irq, struct irq_desc *desc)
+void handle_edge_irq(struct irq_desc *desc)
{
raw_spin_lock(&desc->lock);
@@ -618,13 +610,12 @@ EXPORT_SYMBOL(handle_edge_irq);
#ifdef CONFIG_IRQ_EDGE_EOI_HANDLER
/**
* handle_edge_eoi_irq - edge eoi type IRQ handler
- * @irq: the interrupt number
* @desc: the interrupt description structure for this irq
*
* Similar as the above handle_edge_irq, but using eoi and w/o the
* mask/unmask logic.
*/
-void handle_edge_eoi_irq(unsigned int irq, struct irq_desc *desc)
+void handle_edge_eoi_irq(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
@@ -665,13 +656,11 @@ out_eoi:
/**
* handle_percpu_irq - Per CPU local irq handler
- * @irq: the interrupt number
* @desc: the interrupt description structure for this irq
*
* Per CPU interrupts on SMP machines without locking requirements
*/
-void
-handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
+void handle_percpu_irq(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
@@ -688,7 +677,6 @@ handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
/**
* handle_percpu_devid_irq - Per CPU local irq handler with per cpu dev ids
- * @irq: the interrupt number
* @desc: the interrupt description structure for this irq
*
* Per CPU interrupts on SMP machines without locking requirements. Same as
@@ -698,11 +686,12 @@ handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
* contain the real device id for the cpu on which this handler is
* called
*/
-void handle_percpu_devid_irq(unsigned int irq, struct irq_desc *desc)
+void handle_percpu_devid_irq(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
struct irqaction *action = desc->action;
void *dev_id = raw_cpu_ptr(action->percpu_dev_id);
+ unsigned int irq = irq_desc_get_irq(desc);
irqreturn_t res;
kstat_incr_irqs_this_cpu(desc);
@@ -796,7 +785,7 @@ irq_set_chained_handler_and_data(unsigned int irq, irq_flow_handler_t handle,
return;
__irq_do_set_handler(desc, handle, 1, NULL);
- desc->irq_data.handler_data = data;
+ desc->irq_common_data.handler_data = data;
irq_put_desc_busunlock(desc, flags);
}
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index b6eeea8a80c5..de41a68fc038 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -27,8 +27,10 @@
*
* Handles spurious and unhandled IRQ's. It also prints a debugmessage.
*/
-void handle_bad_irq(unsigned int irq, struct irq_desc *desc)
+void handle_bad_irq(struct irq_desc *desc)
{
+ unsigned int irq = irq_desc_get_irq(desc);
+
print_irq_desc(irq, desc);
kstat_incr_irqs_this_cpu(desc);
ack_bad_irq(irq);
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index eee4b385cffb..5ef0c2dbe930 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -194,7 +194,7 @@ static inline void kstat_incr_irqs_this_cpu(struct irq_desc *desc)
static inline int irq_desc_get_node(struct irq_desc *desc)
{
- return irq_data_get_node(&desc->irq_data);
+ return irq_common_data_get_node(&desc->irq_common_data);
}
#ifdef CONFIG_PM_SLEEP
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 0a2a4b697bcb..239e2ae2c947 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -38,12 +38,13 @@ static void __init init_irq_default_affinity(void)
#ifdef CONFIG_SMP
static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
{
- if (!zalloc_cpumask_var_node(&desc->irq_data.affinity, gfp, node))
+ if (!zalloc_cpumask_var_node(&desc->irq_common_data.affinity,
+ gfp, node))
return -ENOMEM;
#ifdef CONFIG_GENERIC_PENDING_IRQ
if (!zalloc_cpumask_var_node(&desc->pending_mask, gfp, node)) {
- free_cpumask_var(desc->irq_data.affinity);
+ free_cpumask_var(desc->irq_common_data.affinity);
return -ENOMEM;
}
#endif
@@ -52,11 +53,13 @@ static int alloc_masks(struct irq_desc *desc, gfp_t gfp, int node)
static void desc_smp_init(struct irq_desc *desc, int node)
{
- desc->irq_data.node = node;
- cpumask_copy(desc->irq_data.affinity, irq_default_affinity);
+ cpumask_copy(desc->irq_common_data.affinity, irq_default_affinity);
#ifdef CONFIG_GENERIC_PENDING_IRQ
cpumask_clear(desc->pending_mask);
#endif
+#ifdef CONFIG_NUMA
+ desc->irq_common_data.node = node;
+#endif
}
#else
@@ -70,12 +73,13 @@ static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node,
{
int cpu;
+ desc->irq_common_data.handler_data = NULL;
+ desc->irq_common_data.msi_desc = NULL;
+
desc->irq_data.common = &desc->irq_common_data;
desc->irq_data.irq = irq;
desc->irq_data.chip = &no_irq_chip;
desc->irq_data.chip_data = NULL;
- desc->irq_data.handler_data = NULL;
- desc->irq_data.msi_desc = NULL;
irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
irqd_set(&desc->irq_data, IRQD_IRQ_DISABLED);
desc->handle_irq = handle_bad_irq;
@@ -121,7 +125,7 @@ static void free_masks(struct irq_desc *desc)
#ifdef CONFIG_GENERIC_PENDING_IRQ
free_cpumask_var(desc->pending_mask);
#endif
- free_cpumask_var(desc->irq_data.affinity);
+ free_cpumask_var(desc->irq_common_data.affinity);
}
#else
static inline void free_masks(struct irq_desc *desc) { }
@@ -343,7 +347,7 @@ int generic_handle_irq(unsigned int irq)
if (!desc)
return -EINVAL;
- generic_handle_irq_desc(irq, desc);
+ generic_handle_irq_desc(desc);
return 0;
}
EXPORT_SYMBOL_GPL(generic_handle_irq);
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 79baaf8a7813..dc9d27c0c158 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -844,7 +844,6 @@ static struct irq_data *irq_domain_insert_irq_data(struct irq_domain *domain,
child->parent_data = irq_data;
irq_data->irq = child->irq;
irq_data->common = child->common;
- irq_data->node = child->node;
irq_data->domain = domain;
}
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index ad1b064f94fe..f9a59f6cabd2 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -192,7 +192,7 @@ int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask,
switch (ret) {
case IRQ_SET_MASK_OK:
case IRQ_SET_MASK_OK_DONE:
- cpumask_copy(data->affinity, mask);
+ cpumask_copy(desc->irq_common_data.affinity, mask);
case IRQ_SET_MASK_OK_NOCOPY:
irq_set_thread_affinity(desc);
ret = 0;
@@ -304,7 +304,7 @@ static void irq_affinity_notify(struct work_struct *work)
if (irq_move_pending(&desc->irq_data))
irq_get_pending(cpumask, desc);
else
- cpumask_copy(cpumask, desc->irq_data.affinity);
+ cpumask_copy(cpumask, desc->irq_common_data.affinity);
raw_spin_unlock_irqrestore(&desc->lock, flags);
notify->notify(notify, cpumask);
@@ -375,9 +375,9 @@ static int setup_affinity(struct irq_desc *desc, struct cpumask *mask)
* one of the targets is online.
*/
if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) {
- if (cpumask_intersects(desc->irq_data.affinity,
+ if (cpumask_intersects(desc->irq_common_data.affinity,
cpu_online_mask))
- set = desc->irq_data.affinity;
+ set = desc->irq_common_data.affinity;
else
irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
}
@@ -829,8 +829,8 @@ irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action)
* This code is triggered unconditionally. Check the affinity
* mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out.
*/
- if (desc->irq_data.affinity)
- cpumask_copy(mask, desc->irq_data.affinity);
+ if (desc->irq_common_data.affinity)
+ cpumask_copy(mask, desc->irq_common_data.affinity);
else
valid = false;
raw_spin_unlock_irq(&desc->lock);
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index 0e97c142ce40..e3a8c9577ba6 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -39,7 +39,7 @@ static struct proc_dir_entry *root_irq_dir;
static int show_irq_affinity(int type, struct seq_file *m, void *v)
{
struct irq_desc *desc = irq_to_desc((long)m->private);
- const struct cpumask *mask = desc->irq_data.affinity;
+ const struct cpumask *mask = desc->irq_common_data.affinity;
#ifdef CONFIG_GENERIC_PENDING_IRQ
if (irqd_is_setaffinity_pending(&desc->irq_data))
diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c
index dd95f44f99b2..b86886beee4f 100644
--- a/kernel/irq/resend.c
+++ b/kernel/irq/resend.c
@@ -38,7 +38,7 @@ static void resend_irqs(unsigned long arg)
clear_bit(irq, irqs_resend);
desc = irq_to_desc(irq);
local_irq_disable();
- desc->handle_irq(irq, desc);
+ desc->handle_irq(desc);
local_irq_enable();
}
}
diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c
index 337c8818541d..87e9ce6a63c5 100644
--- a/kernel/locking/qspinlock.c
+++ b/kernel/locking/qspinlock.c
@@ -289,7 +289,7 @@ void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
if (pv_enabled())
goto queue;
- if (virt_queued_spin_lock(lock))
+ if (virt_spin_lock(lock))
return;
/*
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 3595403921bd..2f9c92884817 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -621,18 +621,21 @@ int get_nohz_timer_target(void)
int i, cpu = smp_processor_id();
struct sched_domain *sd;
- if (!idle_cpu(cpu))
+ if (!idle_cpu(cpu) && is_housekeeping_cpu(cpu))
return cpu;
rcu_read_lock();
for_each_domain(cpu, sd) {
for_each_cpu(i, sched_domain_span(sd)) {
- if (!idle_cpu(i)) {
+ if (!idle_cpu(i) && is_housekeeping_cpu(cpu)) {
cpu = i;
goto unlock;
}
}
}
+
+ if (!is_housekeeping_cpu(cpu))
+ cpu = housekeeping_any_cpu();
unlock:
rcu_read_unlock();
return cpu;
@@ -2666,13 +2669,20 @@ unsigned long nr_running(void)
/*
* Check if only the current task is running on the cpu.
+ *
+ * Caution: this function does not check that the caller has disabled
+ * preemption, thus the result might have a time-of-check-to-time-of-use
+ * race. The caller is responsible to use it correctly, for example:
+ *
+ * - from a non-preemptable section (of course)
+ *
+ * - from a thread that is bound to a single CPU
+ *
+ * - in a loop with very short iterations (e.g. a polling loop)
*/
bool single_task_running(void)
{
- if (cpu_rq(smp_processor_id())->nr_running == 1)
- return true;
- else
- return false;
+ return raw_rq()->nr_running == 1;
}
EXPORT_SYMBOL(single_task_running);
@@ -5178,24 +5188,47 @@ static void migrate_tasks(struct rq *dead_rq)
break;
/*
- * Ensure rq->lock covers the entire task selection
- * until the migration.
+ * pick_next_task assumes pinned rq->lock.
*/
lockdep_pin_lock(&rq->lock);
next = pick_next_task(rq, &fake_task);
BUG_ON(!next);
next->sched_class->put_prev_task(rq, next);
+ /*
+ * Rules for changing task_struct::cpus_allowed are holding
+ * both pi_lock and rq->lock, such that holding either
+ * stabilizes the mask.
+ *
+ * Drop rq->lock is not quite as disastrous as it usually is
+ * because !cpu_active at this point, which means load-balance
+ * will not interfere. Also, stop-machine.
+ */
+ lockdep_unpin_lock(&rq->lock);
+ raw_spin_unlock(&rq->lock);
+ raw_spin_lock(&next->pi_lock);
+ raw_spin_lock(&rq->lock);
+
+ /*
+ * Since we're inside stop-machine, _nothing_ should have
+ * changed the task, WARN if weird stuff happened, because in
+ * that case the above rq->lock drop is a fail too.
+ */
+ if (WARN_ON(task_rq(next) != rq || !task_on_rq_queued(next))) {
+ raw_spin_unlock(&next->pi_lock);
+ continue;
+ }
+
/* Find suitable destination for @next, with force if needed. */
dest_cpu = select_fallback_rq(dead_rq->cpu, next);
- lockdep_unpin_lock(&rq->lock);
rq = __migrate_task(rq, next, dest_cpu);
if (rq != dead_rq) {
raw_spin_unlock(&rq->lock);
rq = dead_rq;
raw_spin_lock(&rq->lock);
}
+ raw_spin_unlock(&next->pi_lock);
}
rq->stop = stop;
diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c
index 272d9322bc5d..052e02672d12 100644
--- a/kernel/sched/wait.c
+++ b/kernel/sched/wait.c
@@ -106,10 +106,9 @@ void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr)
}
EXPORT_SYMBOL_GPL(__wake_up_locked);
-void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, int nr,
- void *key)
+void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key)
{
- __wake_up_common(q, mode, nr, 0, key);
+ __wake_up_common(q, mode, 1, 0, key);
}
EXPORT_SYMBOL_GPL(__wake_up_locked_key);
@@ -284,7 +283,7 @@ void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait,
if (!list_empty(&wait->task_list))
list_del_init(&wait->task_list);
else if (waitqueue_active(q))
- __wake_up_locked_key(q, mode, 1, key);
+ __wake_up_locked_key(q, mode, key);
spin_unlock_irqrestore(&q->lock, flags);
}
EXPORT_SYMBOL(abort_exclusive_wait);
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 50eb107f1198..a9b76a40319e 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -97,20 +97,6 @@ EXPORT_SYMBOL_GPL(clockevent_delta2ns);
static int __clockevents_switch_state(struct clock_event_device *dev,
enum clock_event_state state)
{
- /* Transition with legacy set_mode() callback */
- if (dev->set_mode) {
- /* Legacy callback doesn't support new modes */
- if (state > CLOCK_EVT_STATE_ONESHOT)
- return -ENOSYS;
- /*
- * 'clock_event_state' and 'clock_event_mode' have 1-to-1
- * mapping until *_ONESHOT, and so a simple cast will work.
- */
- dev->set_mode((enum clock_event_mode)state, dev);
- dev->mode = (enum clock_event_mode)state;
- return 0;
- }
-
if (dev->features & CLOCK_EVT_FEAT_DUMMY)
return 0;
@@ -204,12 +190,8 @@ int clockevents_tick_resume(struct clock_event_device *dev)
{
int ret = 0;
- if (dev->set_mode) {
- dev->set_mode(CLOCK_EVT_MODE_RESUME, dev);
- dev->mode = CLOCK_EVT_MODE_RESUME;
- } else if (dev->tick_resume) {
+ if (dev->tick_resume)
ret = dev->tick_resume(dev);
- }
return ret;
}
@@ -460,26 +442,6 @@ int clockevents_unbind_device(struct clock_event_device *ced, int cpu)
}
EXPORT_SYMBOL_GPL(clockevents_unbind_device);
-/* Sanity check of state transition callbacks */
-static int clockevents_sanity_check(struct clock_event_device *dev)
-{
- /* Legacy set_mode() callback */
- if (dev->set_mode) {
- /* We shouldn't be supporting new modes now */
- WARN_ON(dev->set_state_periodic || dev->set_state_oneshot ||
- dev->set_state_shutdown || dev->tick_resume ||
- dev->set_state_oneshot_stopped);
-
- BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
- return 0;
- }
-
- if (dev->features & CLOCK_EVT_FEAT_DUMMY)
- return 0;
-
- return 0;
-}
-
/**
* clockevents_register_device - register a clock event device
* @dev: device to register
@@ -488,8 +450,6 @@ void clockevents_register_device(struct clock_event_device *dev)
{
unsigned long flags;
- BUG_ON(clockevents_sanity_check(dev));
-
/* Initialize state to DETACHED */
clockevent_set_state(dev, CLOCK_EVT_STATE_DETACHED);
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index d11c55b6ab7d..4fcd99e12aa0 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -398,7 +398,6 @@ void tick_shutdown(unsigned int cpu)
* the set mode function!
*/
clockevent_set_state(dev, CLOCK_EVT_STATE_DETACHED);
- dev->mode = CLOCK_EVT_MODE_UNUSED;
clockevents_exchange_device(dev, NULL);
dev->event_handler = clockevents_handle_noop;
td->evtdev = NULL;
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 3319e16f31e5..7c7ec4515983 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -290,16 +290,17 @@ static int __init tick_nohz_full_setup(char *str)
__setup("nohz_full=", tick_nohz_full_setup);
static int tick_nohz_cpu_down_callback(struct notifier_block *nfb,
- unsigned long action,
- void *hcpu)
+ unsigned long action,
+ void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_DOWN_PREPARE:
/*
- * If we handle the timekeeping duty for full dynticks CPUs,
- * we can't safely shutdown that CPU.
+ * The boot CPU handles housekeeping duty (unbound timers,
+ * workqueues, timekeeping, ...) on behalf of full dynticks
+ * CPUs. It must remain online when nohz full is enabled.
*/
if (tick_nohz_full_running && tick_do_timer_cpu == cpu)
return NOTIFY_BAD;
@@ -370,6 +371,12 @@ void __init tick_nohz_init(void)
cpu_notifier(tick_nohz_cpu_down_callback, 0);
pr_info("NO_HZ: Full dynticks CPUs: %*pbl.\n",
cpumask_pr_args(tick_nohz_full_mask));
+
+ /*
+ * We need at least one CPU to handle housekeeping work such
+ * as timekeeping, unbound timers, workqueues, ...
+ */
+ WARN_ON_ONCE(cpumask_empty(housekeeping_mask));
}
#endif
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index f6ee2e6b6f5d..3739ac6aa473 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1614,7 +1614,7 @@ static __always_inline void timekeeping_freqadjust(struct timekeeper *tk,
negative = (tick_error < 0);
/* Sort out the magnitude of the correction */
- tick_error = abs(tick_error);
+ tick_error = abs64(tick_error);
for (adj = 0; tick_error > interval; adj++)
tick_error >>= 1;
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index 129c96033e46..f75e35b60149 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -225,7 +225,7 @@ print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
(unsigned long long) dev->min_delta_ns);
SEQ_printf(m, " mult: %u\n", dev->mult);
SEQ_printf(m, " shift: %u\n", dev->shift);
- SEQ_printf(m, " mode: %d\n", dev->mode);
+ SEQ_printf(m, " mode: %d\n", clockevent_get_state(dev));
SEQ_printf(m, " next_event: %Ld nsecs\n",
(unsigned long long) ktime_to_ns(dev->next_event));
@@ -233,40 +233,34 @@ print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
print_name_offset(m, dev->set_next_event);
SEQ_printf(m, "\n");
- if (dev->set_mode) {
- SEQ_printf(m, " set_mode: ");
- print_name_offset(m, dev->set_mode);
+ if (dev->set_state_shutdown) {
+ SEQ_printf(m, " shutdown: ");
+ print_name_offset(m, dev->set_state_shutdown);
SEQ_printf(m, "\n");
- } else {
- if (dev->set_state_shutdown) {
- SEQ_printf(m, " shutdown: ");
- print_name_offset(m, dev->set_state_shutdown);
- SEQ_printf(m, "\n");
- }
+ }
- if (dev->set_state_periodic) {
- SEQ_printf(m, " periodic: ");
- print_name_offset(m, dev->set_state_periodic);
- SEQ_printf(m, "\n");
- }
+ if (dev->set_state_periodic) {
+ SEQ_printf(m, " periodic: ");
+ print_name_offset(m, dev->set_state_periodic);
+ SEQ_printf(m, "\n");
+ }
- if (dev->set_state_oneshot) {
- SEQ_printf(m, " oneshot: ");
- print_name_offset(m, dev->set_state_oneshot);
- SEQ_printf(m, "\n");
- }
+ if (dev->set_state_oneshot) {
+ SEQ_printf(m, " oneshot: ");
+ print_name_offset(m, dev->set_state_oneshot);
+ SEQ_printf(m, "\n");
+ }
- if (dev->set_state_oneshot_stopped) {
- SEQ_printf(m, " oneshot stopped: ");
- print_name_offset(m, dev->set_state_oneshot_stopped);
- SEQ_printf(m, "\n");
- }
+ if (dev->set_state_oneshot_stopped) {
+ SEQ_printf(m, " oneshot stopped: ");
+ print_name_offset(m, dev->set_state_oneshot_stopped);
+ SEQ_printf(m, "\n");
+ }
- if (dev->tick_resume) {
- SEQ_printf(m, " resume: ");
- print_name_offset(m, dev->tick_resume);
- SEQ_printf(m, "\n");
- }
+ if (dev->tick_resume) {
+ SEQ_printf(m, " resume: ");
+ print_name_offset(m, dev->tick_resume);
+ SEQ_printf(m, "\n");
}
SEQ_printf(m, " event_handler: ");
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-05-19 02:55:50 +0000