kernel compile error

kernel/hrtimer.c: In function ‘hrtimer_nanosleep’:
kernel/hrtimer.c:1353: error: ‘rem’ undeclared (first use in this function)
kernel/hrtimer.c:1353: error: (Each undeclared identifier is reported only once
kernel/hrtimer.c:1353: error: for each function it appears in.)
make[1]: *** [kernel/hrtimer.o] Error 1
make: *** [kernel] Error 2