MAP_FILE
head = mmap(NULL, (size_t)st.st_size, PROT_READ, MAP_FILE|MAP_PRIVATE,
MAP_FILE | MAP_SHARED, 0, 0);
MAP_FILE | MAP_SHARED, 0, 0);
p = mmap(NULL, map_size, PROT_READ, MAP_FILE | MAP_SHARED, m_test_fd,
MAP_FILE | MAP_SHARED, m_test_fd, offs - pg_offset);
#ifndef MAP_FILE
if ((p = (char *)mmap(0, map_size, PROT_READ, MAP_FILE | MAP_SHARED, fd,
MAP_FILE | MAP_SHARED, fd,
MAP_FILE | MAP_SHARED, fd, 0)) == MAP_FAILED) {
if ((dat = mmap(0, nsize, PROT_READ, MAP_FILE | MAP_PRIVATE, fd, 0))