ksm_use_zero_pages
if (ksm_use_zero_pages && (rmap_item->oldchecksum == zero_checksum)) {
static bool ksm_use_zero_pages __read_mostly;
return sysfs_emit(buf, "%u\n", ksm_use_zero_pages);
ksm_use_zero_pages = value;
ksm_use_zero_pages = false;
if (ksm_use_zero_pages() < 0) {
int ksm_use_zero_pages(void);