The 'tick_usec' is USER_HZ period in usec. do_gettimeofday() should use kernel HZ value. Here is a patch for MIPS. It seems m32r, m68k and sparc have same problem though their HZ and USER_HZ are same for now. Signed-off-by: Atsushi Nemoto <anemo@xxxxxxxxxxxxx> diff --git a/arch/mips/kernel/time.c b/arch/mips/kernel/time.c index 7050b4f..42c94c7 100644 --- a/arch/mips/kernel/time.c +++ b/arch/mips/kernel/time.c @@ -163,7 +163,7 @@ void do_gettimeofday(struct timeval *tv) unsigned long seq; unsigned long lost; unsigned long usec, sec; - unsigned long max_ntp_tick = tick_usec - tickadj; + unsigned long max_ntp_tick; do { seq = read_seqbegin(&xtime_lock); @@ -178,12 +178,13 @@ void do_gettimeofday(struct timeval *tv) * Better to lose some accuracy than have time go backwards.. */ if (unlikely(time_adjust < 0)) { + max_ntp_tick = (USEC_PER_SEC / HZ) - tickadj; usec = min(usec, max_ntp_tick); if (lost) usec += lost * max_ntp_tick; } else if (unlikely(lost)) - usec += lost * tick_usec; + usec += lost * (USEC_PER_SEC / HZ); sec = xtime.tv_sec; usec += (xtime.tv_nsec / 1000);