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-rw-r--r--arch/mips/kvm/mips.c4
-rw-r--r--arch/powerpc/kvm/book3s_hv.c6
-rw-r--r--arch/s390/kvm/interrupt.c2
-rw-r--r--arch/x86/kernel/kvm.c4
-rw-r--r--arch/x86/kvm/lapic.c2
-rw-r--r--include/linux/cpuhotplug.h1
-rw-r--r--include/linux/nmi.h10
-rw-r--r--include/linux/smpboot.h15
-rw-r--r--include/linux/swait.h36
-rw-r--r--kernel/cpu.c5
-rw-r--r--kernel/kthread.c6
-rw-r--r--kernel/power/suspend.c4
-rw-r--r--kernel/rcu/srcutiny.c4
-rw-r--r--kernel/rcu/tree.c8
-rw-r--r--kernel/rcu/tree_exp.h4
-rw-r--r--kernel/rcu/tree_plugin.h12
-rw-r--r--kernel/sched/debug.c31
-rw-r--r--kernel/sched/fair.c1
-rw-r--r--kernel/sched/swait.c32
-rw-r--r--kernel/smpboot.c54
-rw-r--r--kernel/watchdog.c137
-rw-r--r--virt/kvm/arm/arm.c4
-rw-r--r--virt/kvm/arm/psci.c2
-rw-r--r--virt/kvm/async_pf.c2
-rw-r--r--virt/kvm/kvm_main.c4
25 files changed, 170 insertions, 220 deletions
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 7cd76f93a438..f7ea8e21656b 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -515,7 +515,7 @@ int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
dvcpu->arch.wait = 0;
if (swq_has_sleeper(&dvcpu->wq))
- swake_up(&dvcpu->wq);
+ swake_up_one(&dvcpu->wq);
return 0;
}
@@ -1204,7 +1204,7 @@ static void kvm_mips_comparecount_func(unsigned long data)
vcpu->arch.wait = 0;
if (swq_has_sleeper(&vcpu->wq))
- swake_up(&vcpu->wq);
+ swake_up_one(&vcpu->wq);
}
/* low level hrtimer wake routine */
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index de686b340f4a..ee4a8854985e 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -216,7 +216,7 @@ static void kvmppc_fast_vcpu_kick_hv(struct kvm_vcpu *vcpu)
wqp = kvm_arch_vcpu_wq(vcpu);
if (swq_has_sleeper(wqp)) {
- swake_up(wqp);
+ swake_up_one(wqp);
++vcpu->stat.halt_wakeup;
}
@@ -3188,7 +3188,7 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
}
}
- prepare_to_swait(&vc->wq, &wait, TASK_INTERRUPTIBLE);
+ prepare_to_swait_exclusive(&vc->wq, &wait, TASK_INTERRUPTIBLE);
if (kvmppc_vcore_check_block(vc)) {
finish_swait(&vc->wq, &wait);
@@ -3311,7 +3311,7 @@ static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
kvmppc_start_thread(vcpu, vc);
trace_kvm_guest_enter(vcpu);
} else if (vc->vcore_state == VCORE_SLEEPING) {
- swake_up(&vc->wq);
+ swake_up_one(&vc->wq);
}
}
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index daa09f89ca2d..fcb55b02990e 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -1145,7 +1145,7 @@ void kvm_s390_vcpu_wakeup(struct kvm_vcpu *vcpu)
* yield-candidate.
*/
vcpu->preempted = true;
- swake_up(&vcpu->wq);
+ swake_up_one(&vcpu->wq);
vcpu->stat.halt_wakeup++;
}
/*
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 5b2300b818af..a37bda38d205 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -154,7 +154,7 @@ void kvm_async_pf_task_wait(u32 token, int interrupt_kernel)
for (;;) {
if (!n.halted)
- prepare_to_swait(&n.wq, &wait, TASK_UNINTERRUPTIBLE);
+ prepare_to_swait_exclusive(&n.wq, &wait, TASK_UNINTERRUPTIBLE);
if (hlist_unhashed(&n.link))
break;
@@ -188,7 +188,7 @@ static void apf_task_wake_one(struct kvm_task_sleep_node *n)
if (n->halted)
smp_send_reschedule(n->cpu);
else if (swq_has_sleeper(&n->wq))
- swake_up(&n->wq);
+ swake_up_one(&n->wq);
}
static void apf_task_wake_all(void)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index b5cd8465d44f..d536d457517b 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1379,7 +1379,7 @@ static void apic_timer_expired(struct kvm_lapic *apic)
* using swait_active() is safe.
*/
if (swait_active(q))
- swake_up(q);
+ swake_up_one(q);
if (apic_lvtt_tscdeadline(apic))
ktimer->expired_tscdeadline = ktimer->tscdeadline;
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 8796ba387152..4cf06a64bc02 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -164,6 +164,7 @@ enum cpuhp_state {
CPUHP_AP_PERF_POWERPC_NEST_IMC_ONLINE,
CPUHP_AP_PERF_POWERPC_CORE_IMC_ONLINE,
CPUHP_AP_PERF_POWERPC_THREAD_IMC_ONLINE,
+ CPUHP_AP_WATCHDOG_ONLINE,
CPUHP_AP_WORKQUEUE_ONLINE,
CPUHP_AP_RCUTREE_ONLINE,
CPUHP_AP_ONLINE_DYN,
diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index b8d868d23e79..08f9247e9827 100644
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -45,12 +45,18 @@ extern void touch_softlockup_watchdog(void);
extern void touch_softlockup_watchdog_sync(void);
extern void touch_all_softlockup_watchdogs(void);
extern unsigned int softlockup_panic;
-#else
+
+extern int lockup_detector_online_cpu(unsigned int cpu);
+extern int lockup_detector_offline_cpu(unsigned int cpu);
+#else /* CONFIG_SOFTLOCKUP_DETECTOR */
static inline void touch_softlockup_watchdog_sched(void) { }
static inline void touch_softlockup_watchdog(void) { }
static inline void touch_softlockup_watchdog_sync(void) { }
static inline void touch_all_softlockup_watchdogs(void) { }
-#endif
+
+#define lockup_detector_online_cpu NULL
+#define lockup_detector_offline_cpu NULL
+#endif /* CONFIG_SOFTLOCKUP_DETECTOR */
#ifdef CONFIG_DETECT_HUNG_TASK
void reset_hung_task_detector(void);
diff --git a/include/linux/smpboot.h b/include/linux/smpboot.h
index c174844cf663..d0884b525001 100644
--- a/include/linux/smpboot.h
+++ b/include/linux/smpboot.h
@@ -25,8 +25,6 @@ struct smpboot_thread_data;
* parked (cpu offline)
* @unpark: Optional unpark function, called when the thread is
* unparked (cpu online)
- * @cpumask: Internal state. To update which threads are unparked,
- * call smpboot_update_cpumask_percpu_thread().
* @selfparking: Thread is not parked by the park function.
* @thread_comm: The base name of the thread
*/
@@ -40,23 +38,12 @@ struct smp_hotplug_thread {
void (*cleanup)(unsigned int cpu, bool online);
void (*park)(unsigned int cpu);
void (*unpark)(unsigned int cpu);
- cpumask_var_t cpumask;
bool selfparking;
const char *thread_comm;
};
-int smpboot_register_percpu_thread_cpumask(struct smp_hotplug_thread *plug_thread,
- const struct cpumask *cpumask);
-
-static inline int
-smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread)
-{
- return smpboot_register_percpu_thread_cpumask(plug_thread,
- cpu_possible_mask);
-}
+int smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread);
void smpboot_unregister_percpu_thread(struct smp_hotplug_thread *plug_thread);
-void smpboot_update_cpumask_percpu_thread(struct smp_hotplug_thread *plug_thread,
- const struct cpumask *);
#endif
diff --git a/include/linux/swait.h b/include/linux/swait.h
index bf8cb0dee23c..73e06e9986d4 100644
--- a/include/linux/swait.h
+++ b/include/linux/swait.h
@@ -16,7 +16,7 @@
* wait-queues, but the semantics are actually completely different, and
* every single user we have ever had has been buggy (or pointless).
*
- * A "swake_up()" only wakes up _one_ waiter, which is not at all what
+ * A "swake_up_one()" only wakes up _one_ waiter, which is not at all what
* "wake_up()" does, and has led to problems. In other cases, it has
* been fine, because there's only ever one waiter (kvm), but in that
* case gthe whole "simple" wait-queue is just pointless to begin with,
@@ -38,8 +38,8 @@
* all wakeups are TASK_NORMAL in order to avoid O(n) lookups for the right
* sleeper state.
*
- * - the exclusive mode; because this requires preserving the list order
- * and this is hard.
+ * - the !exclusive mode; because that leads to O(n) wakeups, everything is
+ * exclusive.
*
* - custom wake callback functions; because you cannot give any guarantees
* about random code. This also allows swait to be used in RT, such that
@@ -115,7 +115,7 @@ extern void __init_swait_queue_head(struct swait_queue_head *q, const char *name
* CPU0 - waker CPU1 - waiter
*
* for (;;) {
- * @cond = true; prepare_to_swait(&wq_head, &wait, state);
+ * @cond = true; prepare_to_swait_exclusive(&wq_head, &wait, state);
* smp_mb(); // smp_mb() from set_current_state()
* if (swait_active(wq_head)) if (@cond)
* wake_up(wq_head); break;
@@ -157,20 +157,20 @@ static inline bool swq_has_sleeper(struct swait_queue_head *wq)
return swait_active(wq);
}
-extern void swake_up(struct swait_queue_head *q);
+extern void swake_up_one(struct swait_queue_head *q);
extern void swake_up_all(struct swait_queue_head *q);
extern void swake_up_locked(struct swait_queue_head *q);
-extern void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait);
-extern void prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait, int state);
+extern void prepare_to_swait_exclusive(struct swait_queue_head *q, struct swait_queue *wait, int state);
extern long prepare_to_swait_event(struct swait_queue_head *q, struct swait_queue *wait, int state);
extern void __finish_swait(struct swait_queue_head *q, struct swait_queue *wait);
extern void finish_swait(struct swait_queue_head *q, struct swait_queue *wait);
-/* as per ___wait_event() but for swait, therefore "exclusive == 0" */
+/* as per ___wait_event() but for swait, therefore "exclusive == 1" */
#define ___swait_event(wq, condition, state, ret, cmd) \
({ \
+ __label__ __out; \
struct swait_queue __wait; \
long __ret = ret; \
\
@@ -183,20 +183,20 @@ extern void finish_swait(struct swait_queue_head *q, struct swait_queue *wait);
\
if (___wait_is_interruptible(state) && __int) { \
__ret = __int; \
- break; \
+ goto __out; \
} \
\
cmd; \
} \
finish_swait(&wq, &__wait); \
- __ret; \
+__out: __ret; \
})
#define __swait_event(wq, condition) \
(void)___swait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, \
schedule())
-#define swait_event(wq, condition) \
+#define swait_event_exclusive(wq, condition) \
do { \
if (condition) \
break; \
@@ -208,7 +208,7 @@ do { \
TASK_UNINTERRUPTIBLE, timeout, \
__ret = schedule_timeout(__ret))
-#define swait_event_timeout(wq, condition, timeout) \
+#define swait_event_timeout_exclusive(wq, condition, timeout) \
({ \
long __ret = timeout; \
if (!___wait_cond_timeout(condition)) \
@@ -220,7 +220,7 @@ do { \
___swait_event(wq, condition, TASK_INTERRUPTIBLE, 0, \
schedule())
-#define swait_event_interruptible(wq, condition) \
+#define swait_event_interruptible_exclusive(wq, condition) \
({ \
int __ret = 0; \
if (!(condition)) \
@@ -233,7 +233,7 @@ do { \
TASK_INTERRUPTIBLE, timeout, \
__ret = schedule_timeout(__ret))
-#define swait_event_interruptible_timeout(wq, condition, timeout) \
+#define swait_event_interruptible_timeout_exclusive(wq, condition, timeout)\
({ \
long __ret = timeout; \
if (!___wait_cond_timeout(condition)) \
@@ -246,7 +246,7 @@ do { \
(void)___swait_event(wq, condition, TASK_IDLE, 0, schedule())
/**
- * swait_event_idle - wait without system load contribution
+ * swait_event_idle_exclusive - wait without system load contribution
* @wq: the waitqueue to wait on
* @condition: a C expression for the event to wait for
*
@@ -257,7 +257,7 @@ do { \
* condition and doesn't want to contribute to system load. Signals are
* ignored.
*/
-#define swait_event_idle(wq, condition) \
+#define swait_event_idle_exclusive(wq, condition) \
do { \
if (condition) \
break; \
@@ -270,7 +270,7 @@ do { \
__ret = schedule_timeout(__ret))
/**
- * swait_event_idle_timeout - wait up to timeout without load contribution
+ * swait_event_idle_timeout_exclusive - wait up to timeout without load contribution
* @wq: the waitqueue to wait on
* @condition: a C expression for the event to wait for
* @timeout: timeout at which we'll give up in jiffies
@@ -288,7 +288,7 @@ do { \
* or the remaining jiffies (at least 1) if the @condition evaluated
* to %true before the @timeout elapsed.
*/
-#define swait_event_idle_timeout(wq, condition, timeout) \
+#define swait_event_idle_timeout_exclusive(wq, condition, timeout) \
({ \
long __ret = timeout; \
if (!___wait_cond_timeout(condition)) \
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 0db8938fbb23..191097c45fb1 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1344,6 +1344,11 @@ static struct cpuhp_step cpuhp_hp_states[] = {
.startup.single = perf_event_init_cpu,
.teardown.single = perf_event_exit_cpu,
},
+ [CPUHP_AP_WATCHDOG_ONLINE] = {
+ .name = "lockup_detector:online",
+ .startup.single = lockup_detector_online_cpu,
+ .teardown.single = lockup_detector_offline_cpu,
+ },
[CPUHP_AP_WORKQUEUE_ONLINE] = {
.name = "workqueue:online",
.startup.single = workqueue_online_cpu,
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 750cb8082694..11b591ee51ab 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -190,7 +190,7 @@ static void __kthread_parkme(struct kthread *self)
if (!test_bit(KTHREAD_SHOULD_PARK, &self->flags))
break;
- complete_all(&self->parked);
+ complete(&self->parked);
schedule();
}
__set_current_state(TASK_RUNNING);
@@ -465,7 +465,6 @@ void kthread_unpark(struct task_struct *k)
if (test_bit(KTHREAD_IS_PER_CPU, &kthread->flags))
__kthread_bind(k, kthread->cpu, TASK_PARKED);
- reinit_completion(&kthread->parked);
clear_bit(KTHREAD_SHOULD_PARK, &kthread->flags);
/*
* __kthread_parkme() will either see !SHOULD_PARK or get the wakeup.
@@ -493,6 +492,9 @@ int kthread_park(struct task_struct *k)
if (WARN_ON(k->flags & PF_EXITING))
return -ENOSYS;
+ if (WARN_ON_ONCE(test_bit(KTHREAD_SHOULD_PARK, &kthread->flags)))
+ return -EBUSY;
+
set_bit(KTHREAD_SHOULD_PARK, &kthread->flags);
if (k != current) {
wake_up_process(k);
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 87331565e505..70178f6ffdc4 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -92,7 +92,7 @@ static void s2idle_enter(void)
/* Push all the CPUs into the idle loop. */
wake_up_all_idle_cpus();
/* Make the current CPU wait so it can enter the idle loop too. */
- swait_event(s2idle_wait_head,
+ swait_event_exclusive(s2idle_wait_head,
s2idle_state == S2IDLE_STATE_WAKE);
cpuidle_pause();
@@ -160,7 +160,7 @@ void s2idle_wake(void)
raw_spin_lock_irqsave(&s2idle_lock, flags);
if (s2idle_state > S2IDLE_STATE_NONE) {
s2idle_state = S2IDLE_STATE_WAKE;
- swake_up(&s2idle_wait_head);
+ swake_up_one(&s2idle_wait_head);
}
raw_spin_unlock_irqrestore(&s2idle_lock, flags);
}
diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c
index 622792abe41a..04fc2ed71af8 100644
--- a/kernel/rcu/srcutiny.c
+++ b/kernel/rcu/srcutiny.c
@@ -110,7 +110,7 @@ void __srcu_read_unlock(struct srcu_struct *sp, int idx)
WRITE_ONCE(sp->srcu_lock_nesting[idx], newval);
if (!newval && READ_ONCE(sp->srcu_gp_waiting))
- swake_up(&sp->srcu_wq);
+ swake_up_one(&sp->srcu_wq);
}
EXPORT_SYMBOL_GPL(__srcu_read_unlock);
@@ -140,7 +140,7 @@ void srcu_drive_gp(struct work_struct *wp)
idx = sp->srcu_idx;
WRITE_ONCE(sp->srcu_idx, !sp->srcu_idx);
WRITE_ONCE(sp->srcu_gp_waiting, true); /* srcu_read_unlock() wakes! */
- swait_event(sp->srcu_wq, !READ_ONCE(sp->srcu_lock_nesting[idx]));
+ swait_event_exclusive(sp->srcu_wq, !READ_ONCE(sp->srcu_lock_nesting[idx]));
WRITE_ONCE(sp->srcu_gp_waiting, false); /* srcu_read_unlock() cheap. */
/* Invoke the callbacks we removed above. */
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index aa7cade1b9f3..91f888d3b23a 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1727,7 +1727,7 @@ static void rcu_gp_kthread_wake(struct rcu_state *rsp)
!READ_ONCE(rsp->gp_flags) ||
!rsp->gp_kthread)
return;
- swake_up(&rsp->gp_wq);
+ swake_up_one(&rsp->gp_wq);
}
/*
@@ -2002,7 +2002,7 @@ static bool rcu_gp_init(struct rcu_state *rsp)
}
/*
- * Helper function for swait_event_idle() wakeup at force-quiescent-state
+ * Helper function for swait_event_idle_exclusive() wakeup at force-quiescent-state
* time.
*/
static bool rcu_gp_fqs_check_wake(struct rcu_state *rsp, int *gfp)
@@ -2144,7 +2144,7 @@ static int __noreturn rcu_gp_kthread(void *arg)
READ_ONCE(rsp->gpnum),
TPS("reqwait"));
rsp->gp_state = RCU_GP_WAIT_GPS;
- swait_event_idle(rsp->gp_wq, READ_ONCE(rsp->gp_flags) &
+ swait_event_idle_exclusive(rsp->gp_wq, READ_ONCE(rsp->gp_flags) &
RCU_GP_FLAG_INIT);
rsp->gp_state = RCU_GP_DONE_GPS;
/* Locking provides needed memory barrier. */
@@ -2176,7 +2176,7 @@ static int __noreturn rcu_gp_kthread(void *arg)
READ_ONCE(rsp->gpnum),
TPS("fqswait"));
rsp->gp_state = RCU_GP_WAIT_FQS;
- ret = swait_event_idle_timeout(rsp->gp_wq,
+ ret = swait_event_idle_timeout_exclusive(rsp->gp_wq,
rcu_gp_fqs_check_wake(rsp, &gf), j);
rsp->gp_state = RCU_GP_DOING_FQS;
/* Locking provides needed memory barriers. */
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index d40708e8c5d6..d428cc1064c8 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -212,7 +212,7 @@ static void __rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp,
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
if (wake) {
smp_mb(); /* EGP done before wake_up(). */
- swake_up(&rsp->expedited_wq);
+ swake_up_one(&rsp->expedited_wq);
}
break;
}
@@ -518,7 +518,7 @@ static void synchronize_sched_expedited_wait(struct rcu_state *rsp)
jiffies_start = jiffies;
for (;;) {
- ret = swait_event_timeout(
+ ret = swait_event_timeout_exclusive(
rsp->expedited_wq,
sync_rcu_preempt_exp_done_unlocked(rnp_root),
jiffies_stall);
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 7fd12039e512..ad53d133f709 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -1854,8 +1854,8 @@ static void __wake_nocb_leader(struct rcu_data *rdp, bool force,
WRITE_ONCE(rdp_leader->nocb_leader_sleep, false);
del_timer(&rdp->nocb_timer);
raw_spin_unlock_irqrestore(&rdp->nocb_lock, flags);
- smp_mb(); /* ->nocb_leader_sleep before swake_up(). */
- swake_up(&rdp_leader->nocb_wq);
+ smp_mb(); /* ->nocb_leader_sleep before swake_up_one(). */
+ swake_up_one(&rdp_leader->nocb_wq);
} else {
raw_spin_unlock_irqrestore(&rdp->nocb_lock, flags);
}
@@ -2082,7 +2082,7 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp)
*/
trace_rcu_this_gp(rnp, rdp, c, TPS("StartWait"));
for (;;) {
- swait_event_interruptible(
+ swait_event_interruptible_exclusive(
rnp->nocb_gp_wq[c & 0x1],
(d = ULONG_CMP_GE(READ_ONCE(rnp->completed), c)));
if (likely(d))
@@ -2111,7 +2111,7 @@ wait_again:
/* Wait for callbacks to appear. */
if (!rcu_nocb_poll) {
trace_rcu_nocb_wake(my_rdp->rsp->name, my_rdp->cpu, TPS("Sleep"));
- swait_event_interruptible(my_rdp->nocb_wq,
+ swait_event_interruptible_exclusive(my_rdp->nocb_wq,
!READ_ONCE(my_rdp->nocb_leader_sleep));
raw_spin_lock_irqsave(&my_rdp->nocb_lock, flags);
my_rdp->nocb_leader_sleep = true;
@@ -2176,7 +2176,7 @@ wait_again:
raw_spin_unlock_irqrestore(&rdp->nocb_lock, flags);
if (rdp != my_rdp && tail == &rdp->nocb_follower_head) {
/* List was empty, so wake up the follower. */
- swake_up(&rdp->nocb_wq);
+ swake_up_one(&rdp->nocb_wq);
}
}
@@ -2193,7 +2193,7 @@ static void nocb_follower_wait(struct rcu_data *rdp)
{
for (;;) {
trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu, TPS("FollowerSleep"));
- swait_event_interruptible(rdp->nocb_wq,
+ swait_event_interruptible_exclusive(rdp->nocb_wq,
READ_ONCE(rdp->nocb_follower_head));
if (smp_load_acquire(&rdp->nocb_follower_head)) {
/* ^^^ Ensure CB invocation follows _head test. */
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index e593b4118578..c96e89cc4bc7 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -111,20 +111,19 @@ static int sched_feat_set(char *cmp)
cmp += 3;
}
- for (i = 0; i < __SCHED_FEAT_NR; i++) {
- if (strcmp(cmp, sched_feat_names[i]) == 0) {
- if (neg) {
- sysctl_sched_features &= ~(1UL << i);
- sched_feat_disable(i);
- } else {
- sysctl_sched_features |= (1UL << i);
- sched_feat_enable(i);
- }
- break;
- }
+ i = match_string(sched_feat_names, __SCHED_FEAT_NR, cmp);
+ if (i < 0)
+ return i;
+
+ if (neg) {
+ sysctl_sched_features &= ~(1UL << i);
+ sched_feat_disable(i);
+ } else {
+ sysctl_sched_features |= (1UL << i);
+ sched_feat_enable(i);
}
- return i;
+ return 0;
}
static ssize_t
@@ -133,7 +132,7 @@ sched_feat_write(struct file *filp, const char __user *ubuf,
{
char buf[64];
char *cmp;
- int i;
+ int ret;
struct inode *inode;
if (cnt > 63)
@@ -148,10 +147,10 @@ sched_feat_write(struct file *filp, const char __user *ubuf,
/* Ensure the static_key remains in a consistent state */
inode = file_inode(filp);
inode_lock(inode);
- i = sched_feat_set(cmp);
+ ret = sched_feat_set(cmp);
inode_unlock(inode);
- if (i == __SCHED_FEAT_NR)
- return -EINVAL;
+ if (ret < 0)
+ return ret;
*ppos += cnt;
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 2f0a0be4d344..321cd5dcf2e8 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4726,7 +4726,6 @@ static inline int throttled_lb_pair(struct task_group *tg,
throttled_hierarchy(dest_cfs_rq);
}
-/* updated child weight may affect parent so we have to do this bottom up */
static int tg_unthrottle_up(struct task_group *tg, void *data)
{
struct rq *rq = data;
diff --git a/kernel/sched/swait.c b/kernel/sched/swait.c
index b6fb2c3b3ff7..66b59ac77c22 100644
--- a/kernel/sched/swait.c
+++ b/kernel/sched/swait.c
@@ -32,7 +32,7 @@ void swake_up_locked(struct swait_queue_head *q)
}
EXPORT_SYMBOL(swake_up_locked);
-void swake_up(struct swait_queue_head *q)
+void swake_up_one(struct swait_queue_head *q)
{
unsigned long flags;
@@ -40,7 +40,7 @@ void swake_up(struct swait_queue_head *q)
swake_up_locked(q);
raw_spin_unlock_irqrestore(&q->lock, flags);
}
-EXPORT_SYMBOL(swake_up);
+EXPORT_SYMBOL(swake_up_one);
/*
* Does not allow usage from IRQ disabled, since we must be able to
@@ -69,14 +69,14 @@ void swake_up_all(struct swait_queue_head *q)
}
EXPORT_SYMBOL(swake_up_all);
-void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait)
+static void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait)
{
wait->task = current;
if (list_empty(&wait->task_list))
- list_add(&wait->task_list, &q->task_list);
+ list_add_tail(&wait->task_list, &q->task_list);
}
-void prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait, int state)
+void prepare_to_swait_exclusive(struct swait_queue_head *q, struct swait_queue *wait, int state)
{
unsigned long flags;
@@ -85,16 +85,28 @@ void prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait, int
set_current_state(state);
raw_spin_unlock_irqrestore(&q->lock, flags);
}
-EXPORT_SYMBOL(prepare_to_swait);
+EXPORT_SYMBOL(prepare_to_swait_exclusive);
long prepare_to_swait_event(struct swait_queue_head *q, struct swait_queue *wait, int state)
{
- if (signal_pending_state(state, current))
- return -ERESTARTSYS;
+ unsigned long flags;
+ long ret = 0;
- prepare_to_swait(q, wait, state);
+ raw_spin_lock_irqsave(&q->lock, flags);
+ if (unlikely(signal_pending_state(state, current))) {
+ /*
+ * See prepare_to_wait_event(). TL;DR, subsequent swake_up_one()
+ * must not see us.
+ */
+ list_del_init(&wait->task_list);
+ ret = -ERESTARTSYS;
+ } else {
+ __prepare_to_swait(q, wait);
+ set_current_state(state);
+ }
+ raw_spin_unlock_irqrestore(&q->lock, flags);
- return 0;
+ return ret;
}
EXPORT_SYMBOL(prepare_to_swait_event);
diff --git a/kernel/smpboot.c b/kernel/smpboot.c
index 5043e7433f4b..c230c2dd48e1 100644
--- a/kernel/smpboot.c
+++ b/kernel/smpboot.c
@@ -238,8 +238,7 @@ int smpboot_unpark_threads(unsigned int cpu)
mutex_lock(&smpboot_threads_lock);
list_for_each_entry(cur, &hotplug_threads, list)
- if (cpumask_test_cpu(cpu, cur->cpumask))
- smpboot_unpark_thread(cur, cpu);
+ smpboot_unpark_thread(cur, cpu);
mutex_unlock(&smpboot_threads_lock);
return 0;
}
@@ -280,34 +279,26 @@ static void smpboot_destroy_threads(struct smp_hotplug_thread *ht)
}
/**
- * smpboot_register_percpu_thread_cpumask - Register a per_cpu thread related
+ * smpboot_register_percpu_thread - Register a per_cpu thread related
* to hotplug
* @plug_thread: Hotplug thread descriptor
- * @cpumask: The cpumask where threads run
*
* Creates and starts the threads on all online cpus.
*/
-int smpboot_register_percpu_thread_cpumask(struct smp_hotplug_thread *plug_thread,
- const struct cpumask *cpumask)
+int smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread)
{
unsigned int cpu;
int ret = 0;
- if (!alloc_cpumask_var(&plug_thread->cpumask, GFP_KERNEL))
- return -ENOMEM;
- cpumask_copy(plug_thread->cpumask, cpumask);
-
get_online_cpus();
mutex_lock(&smpboot_threads_lock);
for_each_online_cpu(cpu) {
ret = __smpboot_create_thread(plug_thread, cpu);
if (ret) {
smpboot_destroy_threads(plug_thread);
- free_cpumask_var(plug_thread->cpumask);
goto out;
}
- if (cpumask_test_cpu(cpu, cpumask))
- smpboot_unpark_thread(plug_thread, cpu);
+ smpboot_unpark_thread(plug_thread, cpu);
}
list_add(&plug_thread->list, &hotplug_threads);
out:
@@ -315,7 +306,7 @@ out:
put_online_cpus();
return ret;
}
-EXPORT_SYMBOL_GPL(smpboot_register_percpu_thread_cpumask);
+EXPORT_SYMBOL_GPL(smpboot_register_percpu_thread);
/**
* smpboot_unregister_percpu_thread - Unregister a per_cpu thread related to hotplug
@@ -331,44 +322,9 @@ void smpboot_unregister_percpu_thread(struct smp_hotplug_thread *plug_thread)
smpboot_destroy_threads(plug_thread);
mutex_unlock(&smpboot_threads_lock);
put_online_cpus();
- free_cpumask_var(plug_thread->cpumask);
}
EXPORT_SYMBOL_GPL(smpboot_unregister_percpu_thread);
-/**
- * smpboot_update_cpumask_percpu_thread - Adjust which per_cpu hotplug threads stay parked
- * @plug_thread: Hotplug thread descriptor
- * @new: Revised mask to use
- *
- * The cpumask field in the smp_hotplug_thread must not be updated directly
- * by the client, but only by calling this function.
- * This function can only be called on a registered smp_hotplug_thread.
- */
-void smpboot_update_cpumask_percpu_thread(struct smp_hotplug_thread *plug_thread,
- const struct cpumask *new)
-{
- struct cpumask *old = plug_thread->cpumask;
- static struct cpumask tmp;
- unsigned int cpu;
-
- lockdep_assert_cpus_held();
- mutex_lock(&smpboot_threads_lock);
-
- /* Park threads that were exclusively enabled on the old mask. */
- cpumask_andnot(&tmp, old, new);
- for_each_cpu_and(cpu, &tmp, cpu_online_mask)
- smpboot_park_thread(plug_thread, cpu);
-
- /* Unpark threads that are exclusively enabled on the new mask. */
- cpumask_andnot(&tmp, new, old);
- for_each_cpu_and(cpu, &tmp, cpu_online_mask)
- smpboot_unpark_thread(plug_thread, cpu);
-
- cpumask_copy(old, new);
-
- mutex_unlock(&smpboot_threads_lock);
-}
-
static DEFINE_PER_CPU(atomic_t, cpu_hotplug_state) = ATOMIC_INIT(CPU_POST_DEAD);
/*
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 576d18045811..b81f777838d5 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -18,18 +18,14 @@
#include <linux/init.h>
#include <linux/module.h>
#include <linux/sysctl.h>
-#include <linux/smpboot.h>
-#include <linux/sched/rt.h>
-#include <uapi/linux/sched/types.h>
#include <linux/tick.h>
-#include <linux/workqueue.h>
#include <linux/sched/clock.h>
#include <linux/sched/debug.h>
#include <linux/sched/isolation.h>
+#include <linux/stop_machine.h>
#include <asm/irq_regs.h>
#include <linux/kvm_para.h>
-#include <linux/kthread.h>
static DEFINE_MUTEX(watchdog_mutex);
@@ -169,11 +165,10 @@ static void lockup_detector_update_enable(void)
unsigned int __read_mostly softlockup_panic =
CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE;
-static bool softlockup_threads_initialized __read_mostly;
+static bool softlockup_initialized __read_mostly;
static u64 __read_mostly sample_period;
static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts);
-static DEFINE_PER_CPU(struct task_struct *, softlockup_watchdog);
static DEFINE_PER_CPU(struct hrtimer, watchdog_hrtimer);
static DEFINE_PER_CPU(bool, softlockup_touch_sync);
static DEFINE_PER_CPU(bool, soft_watchdog_warn);
@@ -335,6 +330,25 @@ static void watchdog_interrupt_count(void)
__this_cpu_inc(hrtimer_interrupts);
}
+/*
+ * The watchdog thread function - touches the timestamp.
+ *
+ * It only runs once every sample_period seconds (4 seconds by
+ * default) to reset the softlockup timestamp. If this gets delayed
+ * for more than 2*watchdog_thresh seconds then the debug-printout
+ * triggers in watchdog_timer_fn().
+ */
+static int softlockup_fn(void *data)
+{
+ __this_cpu_write(soft_lockup_hrtimer_cnt,
+ __this_cpu_read(hrtimer_interrupts));
+ __touch_watchdog();
+
+ return 0;
+}
+
+static DEFINE_PER_CPU(struct cpu_stop_work, softlockup_stop_work);
+
/* watchdog kicker functions */
static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
{
@@ -350,7 +364,9 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
watchdog_interrupt_count();
/* kick the softlockup detector */
- wake_up_process(__this_cpu_read(softlockup_watchdog));
+ stop_one_cpu_nowait(smp_processor_id(),
+ softlockup_fn, NULL,
+ this_cpu_ptr(&softlockup_stop_work));
/* .. and repeat */
hrtimer_forward_now(hrtimer, ns_to_ktime(sample_period));
@@ -448,17 +464,12 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
return HRTIMER_RESTART;
}
-static void watchdog_set_prio(unsigned int policy, unsigned int prio)
-{
- struct sched_param param = { .sched_priority = prio };
-
- sched_setscheduler(current, policy, &param);
-}
-
static void watchdog_enable(unsigned int cpu)
{
struct hrtimer *hrtimer = this_cpu_ptr(&watchdog_hrtimer);
+ WARN_ON_ONCE(cpu != smp_processor_id());
+
/*
* Start the timer first to prevent the NMI watchdog triggering
* before the timer has a chance to fire.
@@ -473,15 +484,14 @@ static void watchdog_enable(unsigned int cpu)
/* Enable the perf event */
if (watchdog_enabled & NMI_WATCHDOG_ENABLED)
watchdog_nmi_enable(cpu);
-
- watchdog_set_prio(SCHED_FIFO, MAX_RT_PRIO - 1);
}
static void watchdog_disable(unsigned int cpu)
{
struct hrtimer *hrtimer = this_cpu_ptr(&watchdog_hrtimer);
- watchdog_set_prio(SCHED_NORMAL, 0);
+ WARN_ON_ONCE(cpu != smp_processor_id());
+
/*
* Disable the perf event first. That prevents that a large delay
* between disabling the timer and disabling the perf event causes
@@ -491,77 +501,63 @@ static void watchdog_disable(unsigned int cpu)
hrtimer_cancel(hrtimer);
}
-static void watchdog_cleanup(unsigned int cpu, bool online)
+static int softlockup_stop_fn(void *data)
{
- watchdog_disable(cpu);
+ watchdog_disable(smp_processor_id());
+ return 0;
}
-static int watchdog_should_run(unsigned int cpu)
+static void softlockup_stop_all(void)
{
- return __this_cpu_read(hrtimer_interrupts) !=
- __this_cpu_read(soft_lockup_hrtimer_cnt);
+ int cpu;
+
+ if (!softlockup_initialized)
+ return;
+
+ for_each_cpu(cpu, &watchdog_allowed_mask)
+ smp_call_on_cpu(cpu, softlockup_stop_fn, NULL, false);
+
+ cpumask_clear(&watchdog_allowed_mask);
}
-/*
- * The watchdog thread function - touches the timestamp.
- *
- * It only runs once every sample_period seconds (4 seconds by
- * default) to reset the softlockup timestamp. If this gets delayed
- * for more than 2*watchdog_thresh seconds then the debug-printout
- * triggers in watchdog_timer_fn().
- */
-static void watchdog(unsigned int cpu)
+static int softlockup_start_fn(void *data)
{
- __this_cpu_write(soft_lockup_hrtimer_cnt,
- __this_cpu_read(hrtimer_interrupts));
- __touch_watchdog();
+ watchdog_enable(smp_processor_id());
+ return 0;
}
-static struct smp_hotplug_thread watchdog_threads = {
- .store = &softlockup_watchdog,
- .thread_should_run = watchdog_should_run,
- .thread_fn = watchdog,
- .thread_comm = "watchdog/%u",
- .setup = watchdog_enable,
- .cleanup = watchdog_cleanup,
- .park = watchdog_disable,
- .unpark = watchdog_enable,
-};
-
-static void softlockup_update_smpboot_threads(void)
+static void softlockup_start_all(void)
{
- lockdep_assert_held(&watchdog_mutex);
-
- if (!softlockup_threads_initialized)
- return;
+ int cpu;
- smpboot_update_cpumask_percpu_thread(&watchdog_threads,
- &watchdog_allowed_mask);
+ cpumask_copy(&watchdog_allowed_mask, &watchdog_cpumask);
+ for_each_cpu(cpu, &watchdog_allowed_mask)
+ smp_call_on_cpu(cpu, softlockup_start_fn, NULL, false);
}
-/* Temporarily park all watchdog threads */
-static void softlockup_park_all_threads(void)
+int lockup_detector_online_cpu(unsigned int cpu)
{
- cpumask_clear(&watchdog_allowed_mask);
- softlockup_update_smpboot_threads();
+ watchdog_enable(cpu);
+ return 0;
}
-/* Unpark enabled threads */
-static void softlockup_unpark_threads(void)
+int lockup_detector_offline_cpu(unsigned int cpu)
{
- cpumask_copy(&watchdog_allowed_mask, &watchdog_cpumask);
- softlockup_update_smpboot_threads();
+ watchdog_disable(cpu);
+ return 0;
}
static void lockup_detector_reconfigure(void)
{
cpus_read_lock();
watchdog_nmi_stop();
- softlockup_park_all_threads();
+
+ softlockup_stop_all();
set_sample_period();
lockup_detector_update_enable();
if (watchdog_enabled && watchdog_thresh)
- softlockup_unpark_threads();
+ softlockup_start_all();
+
watchdog_nmi_start();
cpus_read_unlock();
/*
@@ -580,8 +576,6 @@ static void lockup_detector_reconfigure(void)
*/
static __init void lockup_detector_setup(void)
{
- int ret;
-
/*
* If sysctl is off and watchdog got disabled on the command line,
* nothing to do here.
@@ -592,24 +586,13 @@ static __init void lockup_detector_setup(void)
!(watchdog_enabled && watchdog_thresh))
return;
- ret = smpboot_register_percpu_thread_cpumask(&watchdog_threads,
- &watchdog_allowed_mask);
- if (ret) {
- pr_err("Failed to initialize soft lockup detector threads\n");
- return;
- }
-
mutex_lock(&watchdog_mutex);
- softlockup_threads_initialized = true;
lockup_detector_reconfigure();
+ softlockup_initialized = true;
mutex_unlock(&watchdog_mutex);
}
#else /* CONFIG_SOFTLOCKUP_DETECTOR */
-static inline int watchdog_park_threads(void) { return 0; }
-static inline void watchdog_unpark_threads(void) { }
-static inline int watchdog_enable_all_cpus(void) { return 0; }
-static inline void watchdog_disable_all_cpus(void) { }
static void lockup_detector_reconfigure(void)
{
cpus_read_lock();
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 04e554cae3a2..108250e4d376 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -604,7 +604,7 @@ void kvm_arm_resume_guest(struct kvm *kvm)
kvm_for_each_vcpu(i, vcpu, kvm) {
vcpu->arch.pause = false;
- swake_up(kvm_arch_vcpu_wq(vcpu));
+ swake_up_one(kvm_arch_vcpu_wq(vcpu));
}
}
@@ -612,7 +612,7 @@ static void vcpu_req_sleep(struct kvm_vcpu *vcpu)
{
struct swait_queue_head *wq = kvm_arch_vcpu_wq(vcpu);
- swait_event_interruptible(*wq, ((!vcpu->arch.power_off) &&
+ swait_event_interruptible_exclusive(*wq, ((!vcpu->arch.power_off) &&
(!vcpu->arch.pause)));
if (vcpu->arch.power_off || vcpu->arch.pause) {
diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c
index c95ab4c5a475..9b73d3ad918a 100644
--- a/virt/kvm/arm/psci.c
+++ b/virt/kvm/arm/psci.c
@@ -155,7 +155,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
smp_mb(); /* Make sure the above is visible */
wq = kvm_arch_vcpu_wq(vcpu);
- swake_up(wq);
+ swake_up_one(wq);
return PSCI_RET_SUCCESS;
}
diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c
index 57bcb27dcf30..23c2519c5b32 100644
--- a/virt/kvm/async_pf.c
+++ b/virt/kvm/async_pf.c
@@ -107,7 +107,7 @@ static void async_pf_execute(struct work_struct *work)
trace_kvm_async_pf_completed(addr, gva);
if (swq_has_sleeper(&vcpu->wq))
- swake_up(&vcpu->wq);
+ swake_up_one(&vcpu->wq);
mmput(mm);
kvm_put_kvm(vcpu->kvm);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 8b47507faab5..3d233ebfbee9 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2172,7 +2172,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
kvm_arch_vcpu_blocking(vcpu);
for (;;) {
- prepare_to_swait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
+ prepare_to_swait_exclusive(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
if (kvm_vcpu_check_block(vcpu) < 0)
break;
@@ -2214,7 +2214,7 @@ bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu)
wqp = kvm_arch_vcpu_wq(vcpu);
if (swq_has_sleeper(wqp)) {
- swake_up(wqp);
+ swake_up_one(wqp);
++vcpu->stat.halt_wakeup;
return true;
}
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-01 15:58:54 +0000