write_to_memfd
write_to_memfd(addr1, size, 'a');
write_to_memfd(addr1, size, 'a');
write_to_memfd(addr1, size, 'b');
write_to_memfd(addr1, size, 'a');
write_to_memfd(addr1, size, 'b');
write_to_memfd(addr1, size, 'a');
write_to_memfd(addr1, size, 'b');