"page allocation failure" 메세지는 어떻게 나오는건가요??

joyins의 이미지

loop0: page allocation failure. order:0, mode:0x20
loop0: page allocation failure. order:0, mode:0x20
loop0: page allocation failure. order:0, mode:0x20
loop0: page allocation failure. order:0, mode:0x20
loop0: page allocation failure. order:0, mode:0x20
loop0: page allocation failure. order:0, mode:0x20
loop0: page allocation failure. order:0, mode:0x20
loop0: page allocation failure. order:0, mode:0x20
loop0: page allocation failure. order:0, mode:0x20
loop0: page allocation failure. order:0, mode:0x20

프로그램을 실행하면 위와 같이 출력이 되는데요..;

스왑 오류일까요??? <스왑 메모리 추가후에 위 메세지가 출력되었음.. 임베디드 리눅스>