Bug#16249505 INNODB REPORTS THAT IT'S GOING TO WAIT FOR I/O BUT THE

I/O IS ASYNC

rb://1934
approved by: Mikael Ronstrom (over email)
    
When submitting AIO read request don't signal that the thread is
about to wait on DISKIO

storage/innobase/buf/buf0rea.c

@@ -177,7 +177,10 @@ buf_read_page_low(
 
 	ut_ad(buf_page_in_file(bpage));
 
-	thd_wait_begin(NULL, THD_WAIT_DISKIO);
+	if (sync) {
+		thd_wait_begin(NULL, THD_WAIT_DISKIO);
+	}
+
 	if (zip_size) {
 		*err = fil_io(OS_FILE_READ | wake_later,
 			      sync, space, zip_size, offset, 0, zip_size,
@@ -189,7 +192,10 @@ buf_read_page_low(
 			      sync, space, 0, offset, 0, UNIV_PAGE_SIZE,
 			      ((buf_block_t*) bpage)->frame, bpage);
 	}
-	thd_wait_end(NULL);
+
+	if (sync) {
+		thd_wait_end(NULL);
+	}
 
 	if (*err == DB_TABLESPACE_DELETED) {
 		buf_read_page_handle_error(bpage);