diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/core.c | 6 | ||||
| -rw-r--r-- | kernel/futex.c | 23 | ||||
| -rw-r--r-- | kernel/sched/cpufreq_schedutil.c | 6 | ||||
| -rw-r--r-- | kernel/watchdog_hld.c | 15 | ||||
| -rw-r--r-- | kernel/workqueue_internal.h | 3 |
5 files changed, 37 insertions, 16 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 9660ee65fbef..42d24bd64ea4 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -901,9 +901,11 @@ list_update_cgroup_event(struct perf_event *event, cpuctx_entry = &cpuctx->cgrp_cpuctx_entry; /* cpuctx->cgrp is NULL unless a cgroup event is active in this CPU .*/ if (add) { + struct perf_cgroup *cgrp = perf_cgroup_from_task(current, ctx); + list_add(cpuctx_entry, this_cpu_ptr(&cgrp_cpuctx_list)); - if (perf_cgroup_from_task(current, ctx) == event->cgrp) - cpuctx->cgrp = event->cgrp; + if (cgroup_is_descendant(cgrp->css.cgroup, event->cgrp->css.cgroup)) + cpuctx->cgrp = cgrp; } else { list_del(cpuctx_entry); cpuctx->cgrp = NULL; diff --git a/kernel/futex.c b/kernel/futex.c index 0d638f008bb1..76ed5921117a 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -903,11 +903,27 @@ void exit_pi_state_list(struct task_struct *curr) */ raw_spin_lock_irq(&curr->pi_lock); while (!list_empty(head)) { - next = head->next; pi_state = list_entry(next, struct futex_pi_state, list); key = pi_state->key; hb = hash_futex(&key); + + /* + * We can race against put_pi_state() removing itself from the + * list (a waiter going away). put_pi_state() will first + * decrement the reference count and then modify the list, so + * its possible to see the list entry but fail this reference + * acquire. + * + * In that case; drop the locks to let put_pi_state() make + * progress and retry the loop. + */ + if (!atomic_inc_not_zero(&pi_state->refcount)) { + raw_spin_unlock_irq(&curr->pi_lock); + cpu_relax(); + raw_spin_lock_irq(&curr->pi_lock); + continue; + } raw_spin_unlock_irq(&curr->pi_lock); spin_lock(&hb->lock); @@ -918,8 +934,10 @@ void exit_pi_state_list(struct task_struct *curr) * task still owns the PI-state: */ if (head->next != next) { + /* retain curr->pi_lock for the loop invariant */ raw_spin_unlock(&pi_state->pi_mutex.wait_lock); spin_unlock(&hb->lock); + put_pi_state(pi_state); continue; } @@ -927,9 +945,8 @@ void exit_pi_state_list(struct task_struct *curr) WARN_ON(list_empty(&pi_state->list)); list_del_init(&pi_state->list); pi_state->owner = NULL; - raw_spin_unlock(&curr->pi_lock); - get_pi_state(pi_state); + raw_spin_unlock(&curr->pi_lock); raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock); spin_unlock(&hb->lock); diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 9209d83ecdcf..ba0da243fdd8 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -649,6 +649,7 @@ static int sugov_start(struct cpufreq_policy *policy) struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu); memset(sg_cpu, 0, sizeof(*sg_cpu)); + sg_cpu->cpu = cpu; sg_cpu->sg_policy = sg_policy; sg_cpu->flags = SCHED_CPUFREQ_RT; sg_cpu->iowait_boost_max = policy->cpuinfo.max_freq; @@ -714,11 +715,6 @@ struct cpufreq_governor *cpufreq_default_governor(void) static int __init sugov_register(void) { - int cpu; - - for_each_possible_cpu(cpu) - per_cpu(sugov_cpu, cpu).cpu = cpu; - return cpufreq_register_governor(&schedutil_gov); } fs_initcall(sugov_register); diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c index 4583feb66393..e449a23e9d59 100644 --- a/kernel/watchdog_hld.c +++ b/kernel/watchdog_hld.c @@ -13,6 +13,7 @@ #define pr_fmt(fmt) "NMI watchdog: " fmt #include <linux/nmi.h> +#include <linux/atomic.h> #include <linux/module.h> #include <linux/sched/debug.h> @@ -22,10 +23,11 @@ static DEFINE_PER_CPU(bool, hard_watchdog_warn); static DEFINE_PER_CPU(bool, watchdog_nmi_touch); static DEFINE_PER_CPU(struct perf_event *, watchdog_ev); +static DEFINE_PER_CPU(struct perf_event *, dead_event); static struct cpumask dead_events_mask; static unsigned long hardlockup_allcpu_dumped; -static unsigned int watchdog_cpus; +static atomic_t watchdog_cpus = ATOMIC_INIT(0); void arch_touch_nmi_watchdog(void) { @@ -189,7 +191,8 @@ void hardlockup_detector_perf_enable(void) if (hardlockup_detector_event_create()) return; - if (!watchdog_cpus++) + /* use original value for check */ + if (!atomic_fetch_inc(&watchdog_cpus)) pr_info("Enabled. Permanently consumes one hw-PMU counter.\n"); perf_event_enable(this_cpu_read(watchdog_ev)); @@ -204,8 +207,10 @@ void hardlockup_detector_perf_disable(void) if (event) { perf_event_disable(event); + this_cpu_write(watchdog_ev, NULL); + this_cpu_write(dead_event, event); cpumask_set_cpu(smp_processor_id(), &dead_events_mask); - watchdog_cpus--; + atomic_dec(&watchdog_cpus); } } @@ -219,7 +224,7 @@ void hardlockup_detector_perf_cleanup(void) int cpu; for_each_cpu(cpu, &dead_events_mask) { - struct perf_event *event = per_cpu(watchdog_ev, cpu); + struct perf_event *event = per_cpu(dead_event, cpu); /* * Required because for_each_cpu() reports unconditionally @@ -227,7 +232,7 @@ void hardlockup_detector_perf_cleanup(void) */ if (event) perf_event_release_kernel(event); - per_cpu(watchdog_ev, cpu) = NULL; + per_cpu(dead_event, cpu) = NULL; } cpumask_clear(&dead_events_mask); } diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h index efdd72e15794..d390d1be3748 100644 --- a/kernel/workqueue_internal.h +++ b/kernel/workqueue_internal.h @@ -10,6 +10,7 @@ #include <linux/workqueue.h> #include <linux/kthread.h> +#include <linux/preempt.h> struct worker_pool; @@ -60,7 +61,7 @@ struct worker { */ static inline struct worker *current_wq_worker(void) { - if (current->flags & PF_WQ_WORKER) + if (in_task() && (current->flags & PF_WQ_WORKER)) return kthread_data(current); return NULL; } |