wp_update_post creating revisions instead of updating the post

I have been trying to update a post in the posts table but for some reason, it is creating a multiple number of revisions but not updating the main post. I have been trying hard for the last one day to figure this out but so far so luck with this.

$post_meta_value = get_post_meta($unit_post_id, $post_meta_key.'_after_id', true);

                      global $wpdb;

                       $my_post = array(
                                      'ID'           => $post_meta_value,
                                      'post_content' => $meta_after_content,
                                      'post_title'  => $meta_after_title,
                                      'post_status' => 'publish'
                                  );

                      wp_update_post($my_post);

                // Update the post into the database

I have looked at the codex, but I am confused about the action mentioned in the code http://ift.tt/QUMCHt