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-rw-r--r--kernel/perf_event.c104
1 files changed, 5 insertions, 99 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 634f86a4..99b9700 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -2206,12 +2206,11 @@ static void free_event_rcu(struct rcu_head *head)
kfree(event);
}
-static void perf_pending_sync(struct perf_event *event);
static void perf_buffer_put(struct perf_buffer *buffer);
static void free_event(struct perf_event *event)
{
- perf_pending_sync(event);
+ irq_work_sync(&event->pending);
if (!event->parent) {
atomic_dec(&nr_events);
@@ -3162,16 +3161,7 @@ void perf_event_wakeup(struct perf_event *event)
}
}
-/*
- * Pending wakeups
- *
- * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
- *
- * The NMI bit means we cannot possibly take locks. Therefore, maintain a
- * single linked list and use cmpxchg() to add entries lockless.
- */
-
-static void perf_pending_event(struct perf_pending_entry *entry)
+static void perf_pending_event(struct irq_work *entry)
{
struct perf_event *event = container_of(entry,
struct perf_event, pending);
@@ -3187,89 +3177,6 @@ static void perf_pending_event(struct perf_pending_entry *entry)
}
}
-#define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
-
-static DEFINE_PER_CPU(struct perf_pending_entry *, perf_pending_head) = {
- PENDING_TAIL,
-};
-
-static void perf_pending_queue(struct perf_pending_entry *entry,
- void (*func)(struct perf_pending_entry *))
-{
- struct perf_pending_entry **head;
-
- if (cmpxchg(&entry->next, NULL, PENDING_TAIL) != NULL)
- return;
-
- entry->func = func;
-
- head = &get_cpu_var(perf_pending_head);
-
- do {
- entry->next = *head;
- } while (cmpxchg(head, entry->next, entry) != entry->next);
-
- set_perf_event_pending();
-
- put_cpu_var(perf_pending_head);
-}
-
-static int __perf_pending_run(void)
-{
- struct perf_pending_entry *list;
- int nr = 0;
-
- list = xchg(&__get_cpu_var(perf_pending_head), PENDING_TAIL);
- while (list != PENDING_TAIL) {
- void (*func)(struct perf_pending_entry *);
- struct perf_pending_entry *entry = list;
-
- list = list->next;
-
- func = entry->func;
- entry->next = NULL;
- /*
- * Ensure we observe the unqueue before we issue the wakeup,
- * so that we won't be waiting forever.
- * -- see perf_not_pending().
- */
- smp_wmb();
-
- func(entry);
- nr++;
- }
-
- return nr;
-}
-
-static inline int perf_not_pending(struct perf_event *event)
-{
- /*
- * If we flush on whatever cpu we run, there is a chance we don't
- * need to wait.
- */
- get_cpu();
- __perf_pending_run();
- put_cpu();
-
- /*
- * Ensure we see the proper queue state before going to sleep
- * so that we do not miss the wakeup. -- see perf_pending_handle()
- */
- smp_rmb();
- return event->pending.next == NULL;
-}
-
-static void perf_pending_sync(struct perf_event *event)
-{
- wait_event(event->waitq, perf_not_pending(event));
-}
-
-void perf_event_do_pending(void)
-{
- __perf_pending_run();
-}
-
/*
* We assume there is only KVM supporting the callbacks.
* Later on, we might change it to a list if there is
@@ -3319,8 +3226,7 @@ static void perf_output_wakeup(struct perf_output_handle *handle)
if (handle->nmi) {
handle->event->pending_wakeup = 1;
- perf_pending_queue(&handle->event->pending,
- perf_pending_event);
+ irq_work_queue(&handle->event->pending);
} else
perf_event_wakeup(handle->event);
}
@@ -4356,8 +4262,7 @@ static int __perf_event_overflow(struct perf_event *event, int nmi,
event->pending_kill = POLL_HUP;
if (nmi) {
event->pending_disable = 1;
- perf_pending_queue(&event->pending,
- perf_pending_event);
+ irq_work_queue(&event->pending);
} else
perf_event_disable(event);
}
@@ -5374,6 +5279,7 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
INIT_LIST_HEAD(&event->event_entry);
INIT_LIST_HEAD(&event->sibling_list);
init_waitqueue_head(&event->waitq);
+ init_irq_work(&event->pending, perf_pending_event);
mutex_init(&event->mmap_mutex);