Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

[karo-tx-linux.git] / kernel / events / ring_buffer.c

diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 96472824a752f76fe651ec1bfb7ab7a52411a12c..b2be01b1aa9dcb7a70792fa381c264b229a106d0 100644 (file)
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -221,6 +221,8 @@ void perf_output_end(struct perf_output_handle *handle)
        rcu_read_unlock();
 }
 
+static void rb_irq_work(struct irq_work *work);
+
 static void
 ring_buffer_init(struct ring_buffer *rb, long watermark, int flags)
 {
@@ -241,6 +243,16 @@ ring_buffer_init(struct ring_buffer *rb, long watermark, int flags)
 
        INIT_LIST_HEAD(&rb->event_list);
        spin_lock_init(&rb->event_lock);
+       init_irq_work(&rb->irq_work, rb_irq_work);
+}
+
+static void ring_buffer_put_async(struct ring_buffer *rb)
+{
+       if (!atomic_dec_and_test(&rb->refcount))
+               return;
+
+       rb->rcu_head.next = (void *)rb;
+       irq_work_queue(&rb->irq_work);
 }
 
 /*
@@ -319,7 +331,7 @@ err_put:
        rb_free_aux(rb);
 
 err:
-       ring_buffer_put(rb);
+       ring_buffer_put_async(rb);
        handle->event = NULL;
 
        return NULL;
@@ -370,7 +382,7 @@ void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size,
 
        local_set(&rb->aux_nest, 0);
        rb_free_aux(rb);
-       ring_buffer_put(rb);
+       ring_buffer_put_async(rb);
 }
 
 /*
@@ -557,7 +569,18 @@ static void __rb_free_aux(struct ring_buffer *rb)
 void rb_free_aux(struct ring_buffer *rb)
 {
        if (atomic_dec_and_test(&rb->aux_refcount))
+               irq_work_queue(&rb->irq_work);
+}
+
+static void rb_irq_work(struct irq_work *work)
+{
+       struct ring_buffer *rb = container_of(work, struct ring_buffer, irq_work);
+
+       if (!atomic_read(&rb->aux_refcount))
                __rb_free_aux(rb);
+
+       if (rb->rcu_head.next == (void *)rb)
+               call_rcu(&rb->rcu_head, rb_free_rcu);
 }
 
 #ifndef CONFIG_PERF_USE_VMALLOC