si_mem_available
num_pages_avail = si_mem_available();
avail_pages = si_mem_available();
available = si_mem_available();
n_pages = min(-credit, si_mem_available());
if (si_mem_available() < nr_pages)
available = si_mem_available();
extern long si_mem_available(void);
mem_during = mem_begin = si_mem_available();
mem_during = (mem_during + si_mem_available()) / 2;
i = si_mem_available();
(si_mem_available() == 0) && !list_empty(&folio_list)) {
EXPORT_SYMBOL_GPL(si_mem_available);