Merge branch 'drm-intel-fixes' of git://people.freedesktop.org/~danvet/drm-intel...

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

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index f765465bffe47968752e272308d7fb5b63093a65..49491fa7daa2d35546a6e5ba46d73103594c384e 100644 (file)
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -3239,6 +3239,10 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
        if (cpu_buffer->commit_page == cpu_buffer->reader_page)
                goto out;
 
+       /* Don't bother swapping if the ring buffer is empty */
+       if (rb_num_of_entries(cpu_buffer) == 0)
+               goto out;
+
        /*
         * Reset the reader page to size zero.
         */