time(7) Miscellaneous Information Manual time(7) time - ( ) ( ) ( ). (CPU) . . CPU . CPU ( ). time(1) CPU . CPU times(2) getrusage(2) clock(3). ( ) . rtc(4) hwclock(8). HZ jiffies ( select(2) sigtimedwait(2)) CPU ( getrusage(2)) jiffies. jiffy HZ. HZ . i386 : Linux 2.4.x HZ 100 jiffy 0.01 Linux 2.6.0 HZ 1000 jiffy 0.001 . Linux 2.6.13 HZ 100 250 () 1000 jiffies 0.01 0.004 0.001 . Linux 2.6.20 : 300 (PAL 25 NTSC 30 ). times(2) . USER_HZ. sysconf(_SC_CLK_TCK). ( CPU ). clock_gettime(2). clock_settime(2). time_namespaces(7). Linux 2.6.21 ( ) jiffy. Linux 2.6.21 Linux (HRTs) CONFIG_HIGH_RES_TIMERS. HRTs jiffy ( ). clock_getres(2) "resolution" /proc/timer_list. HRTs . ( x86 ARM PowerPC .) UNIX 1970-01-01 00:00:00 +0000 (UTC). clock_gettime(2) CLOCK_REALTIME ( ) time(2) . clock_settime(2). tm ( ). tm(3type) . ctime(3) strftime(3) strptime(3). ( ) nanosleep(2) clock_nanosleep(2) sleep(3). alarm(2) getitimer(2) timerfd_create(2) timer_create(2). 2.6.28 " " (timer slack) . . . PR_SET_TIMERSLACK prctl(2). date(1) time(1) timeout(1) adjtimex(2) alarm(2) clock_gettime(2) clock_nanosleep(2) getitimer(2) getrlimit(2) getrusage(2) gettimeofday(2) nanosleep(2) stat(2) time(2) timer_create(2) timerfd_create(2) times(2) utime(2) adjtime(3) clock(3) clock_getcpuclockid(3) ctime(3) ntp_adjtime(3) ntp_gettime(3) pthread_getcpuclockid(3) sleep(3) strftime(3) strptime(3) timeradd(3) usleep(3) rtc(4) time_namespaces(7) hwclock(8) 3 . . : . 6.18 8 2026 time(7)