perf: passing struct perf_event to function setup_aux()

[firefly-linux-kernel-4.4.55.git] / kernel / events / ring_buffer.c

diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index dcd21cae982c478a8e46a93d77fb66d0aad71962..8c60a4eb408057f9143f2d5c01c8047f145a5463 100644 (file)
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -252,6 +252,10 @@ ring_buffer_init(struct ring_buffer *rb, long watermark, int flags)
  * The ordering is similar to that of perf_output_{begin,end}, with
  * the exception of (B), which should be taken care of by the pmu
  * driver, since ordering rules will differ depending on hardware.
+ *
+ * Call this from pmu::start(); see the comment in perf_aux_output_end()
+ * about its use in pmu callbacks. Both can also be called from the PMI
+ * handler if needed.
  */
 void *perf_aux_output_begin(struct perf_output_handle *handle,
                            struct perf_event *event)
@@ -323,6 +327,7 @@ void *perf_aux_output_begin(struct perf_output_handle *handle,
        return handle->rb->aux_priv;
 
 err_put:
+       /* can't be last */
        rb_free_aux(rb);
 
 err:
@@ -337,6 +342,10 @@ err:
  * aux_head and posting a PERF_RECORD_AUX into the perf buffer. It is the
  * pmu driver's responsibility to observe ordering rules of the hardware,
  * so that all the data is externally visible before this is called.
+ *
+ * Note: this has to be called from pmu::stop() callback, as the assumption
+ * of the AUX buffer management code is that after pmu::stop(), the AUX
+ * transaction must be stopped and therefore drop the AUX reference count.
  */
 void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size,
                         bool truncated)
@@ -384,6 +393,7 @@ void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size,
        handle->event = NULL;
 
        local_set(&rb->aux_nest, 0);
+       /* can't be last */
        rb_free_aux(rb);
        ring_buffer_put(rb);
 }
@@ -552,7 +562,7 @@ int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
                        goto out;
        }
 
-       rb->aux_priv = event->pmu->setup_aux(event->cpu, rb->aux_pages, nr_pages,
+       rb->aux_priv = event->pmu->setup_aux(event, rb->aux_pages, nr_pages,
                                             overwrite);
        if (!rb->aux_priv)
                goto out;