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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
commite5fd91f1ef340da553f7a79da9540c3db711c937 (patch)
treeb11842027dc6641da63f4bcc524f8678263304a3 /kernel/events/ring_buffer.c
parent2a9b0348e685a63d97486f6749622b61e9e3292f (diff)
Linux-libre 4.2-gnu
Diffstat (limited to 'kernel/events/ring_buffer.c')
-rw-r--r--kernel/events/ring_buffer.c39
1 files changed, 32 insertions, 7 deletions
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 725c41608..c8aa3f75b 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -141,7 +141,7 @@ int perf_output_begin(struct perf_output_handle *handle,
perf_output_get_handle(handle);
do {
- tail = ACCESS_ONCE(rb->user_page->data_tail);
+ tail = READ_ONCE_CTRL(rb->user_page->data_tail);
offset = head = local_read(&rb->head);
if (!rb->overwrite &&
unlikely(CIRC_SPACE(head, tail, perf_data_size(rb)) < size))
@@ -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);
}
/*
@@ -547,17 +559,30 @@ static void __rb_free_aux(struct ring_buffer *rb)
rb->aux_priv = NULL;
}
- for (pg = 0; pg < rb->aux_nr_pages; pg++)
- rb_free_aux_page(rb, pg);
+ if (rb->aux_nr_pages) {
+ for (pg = 0; pg < rb->aux_nr_pages; pg++)
+ rb_free_aux_page(rb, pg);
- kfree(rb->aux_pages);
- rb->aux_nr_pages = 0;
+ kfree(rb->aux_pages);
+ rb->aux_nr_pages = 0;
+ }
}
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