Merge tag '5.14-rc5-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6

[linux-2.6-microblaze.git] / kernel / trace / ring_buffer.c

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index d1463ea..e592d1d 100644 (file)
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -3880,10 +3880,30 @@ static bool rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer)
        if (unlikely(!head))
                return true;
 
-       return reader->read == rb_page_commit(reader) &&
-               (commit == reader ||
-                (commit == head &&
-                 head->read == rb_page_commit(commit)));
+       /* Reader should exhaust content in reader page */
+       if (reader->read != rb_page_commit(reader))
+               return false;
+
+       /*
+        * If writers are committing on the reader page, knowing all
+        * committed content has been read, the ring buffer is empty.
+        */
+       if (commit == reader)
+               return true;
+
+       /*
+        * If writers are committing on a page other than reader page
+        * and head page, there should always be content to read.
+        */
+       if (commit != head)
+               return false;
+
+       /*
+        * Writers are committing on the head page, we just need
+        * to care about there're committed data, and the reader will
+        * swap reader page with head page when it is to read data.
+        */
+       return rb_page_commit(commit) == 0;
 }
 
 /**