diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cgroup.c | 11 | ||||
| -rw-r--r-- | kernel/futex.c | 53 | ||||
| -rw-r--r-- | kernel/sched/clock.c | 4 | ||||
| -rw-r--r-- | kernel/sched/core.c | 9 | ||||
| -rw-r--r-- | kernel/stop_machine.c | 2 | ||||
| -rw-r--r-- | kernel/trace/trace_events.c | 6 | ||||
| -rw-r--r-- | kernel/trace/trace_export.c | 7 |
7 files changed, 64 insertions, 28 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 105f273b6f86..0c753ddd223b 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -4112,17 +4112,17 @@ static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss) err = percpu_ref_init(&css->refcnt, css_release); if (err) - goto err_free; + goto err_free_css; init_css(css, ss, cgrp); err = cgroup_populate_dir(cgrp, 1 << ss->subsys_id); if (err) - goto err_free; + goto err_free_percpu_ref; err = online_css(css); if (err) - goto err_free; + goto err_clear_dir; dget(cgrp->dentry); css_get(css->parent); @@ -4138,8 +4138,11 @@ static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss) return 0; -err_free: +err_clear_dir: + cgroup_clear_dir(css->cgroup, 1 << css->ss->subsys_id); +err_free_percpu_ref: percpu_ref_cancel_init(&css->refcnt); +err_free_css: ss->css_free(css); return err; } diff --git a/kernel/futex.c b/kernel/futex.c index 44a1261cb9ff..08ec814ad9d2 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -234,6 +234,7 @@ static const struct futex_q futex_q_init = { * waiting on a futex. */ struct futex_hash_bucket { + atomic_t waiters; spinlock_t lock; struct plist_head chain; } ____cacheline_aligned_in_smp; @@ -253,22 +254,37 @@ static inline void futex_get_mm(union futex_key *key) smp_mb__after_atomic_inc(); } -static inline bool hb_waiters_pending(struct futex_hash_bucket *hb) +/* + * Reflects a new waiter being added to the waitqueue. + */ +static inline void hb_waiters_inc(struct futex_hash_bucket *hb) { #ifdef CONFIG_SMP + atomic_inc(&hb->waiters); /* - * Tasks trying to enter the critical region are most likely - * potential waiters that will be added to the plist. Ensure - * that wakers won't miss to-be-slept tasks in the window between - * the wait call and the actual plist_add. + * Full barrier (A), see the ordering comment above. */ - if (spin_is_locked(&hb->lock)) - return true; - smp_rmb(); /* Make sure we check the lock state first */ + smp_mb__after_atomic_inc(); +#endif +} + +/* + * Reflects a waiter being removed from the waitqueue by wakeup + * paths. + */ +static inline void hb_waiters_dec(struct futex_hash_bucket *hb) +{ +#ifdef CONFIG_SMP + atomic_dec(&hb->waiters); +#endif +} - return !plist_head_empty(&hb->chain); +static inline int hb_waiters_pending(struct futex_hash_bucket *hb) +{ +#ifdef CONFIG_SMP + return atomic_read(&hb->waiters); #else - return true; + return 1; #endif } @@ -954,6 +970,7 @@ static void __unqueue_futex(struct futex_q *q) hb = container_of(q->lock_ptr, struct futex_hash_bucket, lock); plist_del(&q->list, &hb->chain); + hb_waiters_dec(hb); } /* @@ -1257,7 +1274,9 @@ void requeue_futex(struct futex_q *q, struct futex_hash_bucket *hb1, */ if (likely(&hb1->chain != &hb2->chain)) { plist_del(&q->list, &hb1->chain); + hb_waiters_dec(hb1); plist_add(&q->list, &hb2->chain); + hb_waiters_inc(hb2); q->lock_ptr = &hb2->lock; } get_futex_key_refs(key2); @@ -1600,6 +1619,17 @@ static inline struct futex_hash_bucket *queue_lock(struct futex_q *q) struct futex_hash_bucket *hb; hb = hash_futex(&q->key); + + /* + * Increment the counter before taking the lock so that + * a potential waker won't miss a to-be-slept task that is + * waiting for the spinlock. This is safe as all queue_lock() + * users end up calling queue_me(). Similarly, for housekeeping, + * decrement the counter at queue_unlock() when some error has + * occurred and we don't end up adding the task to the list. + */ + hb_waiters_inc(hb); + q->lock_ptr = &hb->lock; spin_lock(&hb->lock); /* implies MB (A) */ @@ -1611,6 +1641,7 @@ queue_unlock(struct futex_hash_bucket *hb) __releases(&hb->lock) { spin_unlock(&hb->lock); + hb_waiters_dec(hb); } /** @@ -2342,6 +2373,7 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb, * Unqueue the futex_q and determine which it was. */ plist_del(&q->list, &hb->chain); + hb_waiters_dec(hb); /* Handle spurious wakeups gracefully */ ret = -EWOULDBLOCK; @@ -2875,6 +2907,7 @@ static int __init futex_init(void) futex_cmpxchg_enabled = 1; for (i = 0; i < futex_hashsize; i++) { + atomic_set(&futex_queues[i].waiters, 0); plist_head_init(&futex_queues[i].chain); spin_lock_init(&futex_queues[i].lock); } diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c index 43c2bcc35761..b30a2924ef14 100644 --- a/kernel/sched/clock.c +++ b/kernel/sched/clock.c @@ -301,14 +301,14 @@ u64 sched_clock_cpu(int cpu) if (unlikely(!sched_clock_running)) return 0ull; - preempt_disable(); + preempt_disable_notrace(); scd = cpu_sdc(cpu); if (cpu != smp_processor_id()) clock = sched_clock_remote(scd); else clock = sched_clock_local(scd); - preempt_enable(); + preempt_enable_notrace(); return clock; } diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 6edbef296ece..f5c6635b806c 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3338,6 +3338,15 @@ recheck: return -EPERM; } + /* + * Can't set/change SCHED_DEADLINE policy at all for now + * (safest behavior); in the future we would like to allow + * unprivileged DL tasks to increase their relative deadline + * or reduce their runtime (both ways reducing utilization) + */ + if (dl_policy(policy)) + return -EPERM; + /* * Treat SCHED_IDLE as nice 20. Only allow a switch to * SCHED_NORMAL if the RLIMIT_NICE would normally permit it. diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 84571e09c907..01fbae5b97b7 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -293,7 +293,7 @@ int stop_two_cpus(unsigned int cpu1, unsigned int cpu2, cpu_stop_fn_t fn, void * */ smp_call_function_single(min(cpu1, cpu2), &irq_cpu_stop_queue_work, - &call_args, 0); + &call_args, 1); lg_local_unlock(&stop_cpus_lock); preempt_enable(); diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index f3989ceb5cd5..7b16d40bd64d 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -27,12 +27,6 @@ DEFINE_MUTEX(event_mutex); -DEFINE_MUTEX(event_storage_mutex); -EXPORT_SYMBOL_GPL(event_storage_mutex); - -char event_storage[EVENT_STORAGE_SIZE]; -EXPORT_SYMBOL_GPL(event_storage); - LIST_HEAD(ftrace_events); static LIST_HEAD(ftrace_common_fields); diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c index 7c3e3e72e2b6..ee0a5098ac43 100644 --- a/kernel/trace/trace_export.c +++ b/kernel/trace/trace_export.c @@ -95,15 +95,12 @@ static void __always_unused ____ftrace_check_##name(void) \ #undef __array #define __array(type, item, len) \ do { \ + char *type_str = #type"["__stringify(len)"]"; \ BUILD_BUG_ON(len > MAX_FILTER_STR_VAL); \ - mutex_lock(&event_storage_mutex); \ - snprintf(event_storage, sizeof(event_storage), \ - "%s[%d]", #type, len); \ - ret = trace_define_field(event_call, event_storage, #item, \ + ret = trace_define_field(event_call, type_str, #item, \ offsetof(typeof(field), item), \ sizeof(field.item), \ is_signed_type(type), filter_type); \ - mutex_unlock(&event_storage_mutex); \ if (ret) \ return ret; \ } while (0); |