page_cache_ra_unbounded
page_cache_ra_unbounded(&ractl, len, 0);
page_cache_ra_unbounded(&ractl, nr_pages, 0);
void page_cache_ra_unbounded(struct readahead_control *,
TRACE_EVENT(page_cache_ra_unbounded,
EXPORT_SYMBOL_GPL(page_cache_ra_unbounded);
page_cache_ra_unbounded(ractl, nr_to_read, lookahead_size);