[PATCH] Some clean up of the time code.

From: george anzinger (george@mvista.com)
Date: Mon Jun 09 2003 - 17:57:43 EST


This is an update of a patch I sent some time ago. You could not
apply it then because of some other stuff... Let me know if I need to
use a different base system...

I will send Eric's patch soon...

This patch does the following:

Pushs down the change from timeval to timespec in the settime routines.

Fixes two places where time was set without updating the monotonic
clock offset. (Changes sys_stime() to call do_settimeofday() and
changes clock_warp to do the update directly.) These were bugs!

Changes the uptime code to use the posix_clock_monotonic notion of
uptime instead of the jiffies. This time will track NTP changes and
so should be better than your standard wristwatch (if your using ntp).

Changes posix_clock_monotonic to start at 0 on boot (was set to start
at initial jiffies).

Fixes a bug (never experienced) in timer_create() in posix-timers.c
where we "could" have released timer_id 0 if "id resources" were low.

Adds a test in do_settimeofday() to error out (EINVAL) attempts to use
unnormalized times. This is passed back up to both settimeofday and
posix_setclock().

Warning: Requires changes in .../arch/???/kernel/time.c to change
do_settimeofday() to return an error if time is not normalized and to
use a timespec instead of timeval for its input.

-- 
George Anzinger   george@mvista.com
High-res-timers:  http://sourceforge.net/projects/high-res-timers/
Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml

diff -urP -I '\$Id:.*Exp \$' -X /usr/src/patch.exclude linux-2.5.70-kb/arch/i386/kernel/time.c linux/arch/i386/kernel/time.c --- linux-2.5.70-kb/arch/i386/kernel/time.c 2003-05-05 15:33:31.000000000 -0700 +++ linux/arch/i386/kernel/time.c 2003-05-30 01:29:48.000000000 -0700 @@ -114,8 +114,11 @@ tv->tv_usec = usec; } -void do_settimeofday(struct timeval *tv) +int do_settimeofday(struct timespec *tv) { + if ((unsigned long)tv->tv_nsec > NSEC_PER_SEC) + return -EINVAL; + write_seqlock_irq(&xtime_lock); /* * This is revolting. We need to set "xtime" correctly. However, the @@ -123,17 +126,16 @@ * wall time. Discover what correction gettimeofday() would have * made, and then undo it! */ - tv->tv_usec -= timer->get_offset(); - tv->tv_usec -= (jiffies - wall_jiffies) * (USEC_PER_SEC / HZ); + tv->tv_nsec -= timer->get_offset() * NSEC_PER_USEC; + tv->tv_nsec -= (jiffies - wall_jiffies) * TICK_NSEC(TICK_USEC); - while (tv->tv_usec < 0) { - tv->tv_usec += USEC_PER_SEC; + while (tv->tv_nsec < 0) { + tv->tv_nsec += NSEC_PER_SEC; tv->tv_sec--; } - tv->tv_usec *= NSEC_PER_USEC; wall_to_monotonic.tv_sec += xtime.tv_sec - tv->tv_sec; - wall_to_monotonic.tv_nsec += xtime.tv_nsec - tv->tv_usec; + wall_to_monotonic.tv_nsec += xtime.tv_nsec - tv->tv_nsec; if (wall_to_monotonic.tv_nsec > NSEC_PER_SEC) { wall_to_monotonic.tv_nsec -= NSEC_PER_SEC; @@ -145,13 +147,14 @@ } xtime.tv_sec = tv->tv_sec; - xtime.tv_nsec = tv->tv_usec; + xtime.tv_nsec = tv->tv_nsec; time_adjust = 0; /* stop active adjtime() */ time_status |= STA_UNSYNC; time_maxerror = NTP_PHASE_LIMIT; time_esterror = NTP_PHASE_LIMIT; write_sequnlock_irq(&xtime_lock); clock_was_set(); + return 0; } static int set_rtc_mmss(unsigned long nowtime) @@ -299,9 +302,9 @@ { xtime.tv_sec = get_cmos_time(); - wall_to_monotonic.tv_sec = -xtime.tv_sec + INITIAL_JIFFIES / HZ; + wall_to_monotonic.tv_sec = -xtime.tv_sec; xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ); - wall_to_monotonic.tv_nsec = 0; + wall_to_monotonic.tv_nsec = -xtime.tv_nsec; timer = select_timer(); diff -urP -I '\$Id:.*Exp \$' -X /usr/src/patch.exclude linux-2.5.70-kb/fs/proc/proc_misc.c linux/fs/proc/proc_misc.c --- linux-2.5.70-kb/fs/proc/proc_misc.c 2003-05-30 01:18:10.000000000 -0700 +++ linux/fs/proc/proc_misc.c 2003-05-30 01:29:48.000000000 -0700 @@ -137,36 +137,19 @@ static int uptime_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data) { - u64 uptime; - unsigned long uptime_remainder; + struct timespec uptime; + struct timespec idle; int len; + u64 idle_jiffies = init_task.utime + init_task.stime; - uptime = get_jiffies_64() - INITIAL_JIFFIES; - uptime_remainder = (unsigned long) do_div(uptime, HZ); + do_posix_clock_monotonic_gettime(&uptime); + jiffies_to_timespec(idle_jiffies, &idle); + len = sprintf(page,"%lu.%02lu %lu.%02lu\n", + (unsigned long) uptime.tv_sec, + (uptime.tv_nsec / (NSEC_PER_SEC / 100)), + (unsigned long) idle.tv_sec, + (idle.tv_nsec / (NSEC_PER_SEC / 100))); -#if HZ!=100 - { - u64 idle = init_task.utime + init_task.stime; - unsigned long idle_remainder; - - idle_remainder = (unsigned long) do_div(idle, HZ); - len = sprintf(page,"%lu.%02lu %lu.%02lu\n", - (unsigned long) uptime, - (uptime_remainder * 100) / HZ, - (unsigned long) idle, - (idle_remainder * 100) / HZ); - } -#else - { - unsigned long idle = init_task.utime + init_task.stime; - - len = sprintf(page,"%lu.%02lu %lu.%02lu\n", - (unsigned long) uptime, - uptime_remainder, - idle / HZ, - idle % HZ); - } -#endif return proc_calc_metrics(page, start, off, count, eof, len); } diff -urP -I '\$Id:.*Exp \$' -X /usr/src/patch.exclude linux-2.5.70-kb/include/linux/time.h linux/include/linux/time.h --- linux-2.5.70-kb/include/linux/time.h 2003-05-30 01:18:18.000000000 -0700 +++ linux/include/linux/time.h 2003-05-30 01:29:48.000000000 -0700 @@ -200,9 +200,10 @@ #ifdef __KERNEL__ extern void do_gettimeofday(struct timeval *tv); -extern void do_settimeofday(struct timeval *tv); -extern int do_sys_settimeofday(struct timeval *tv, struct timezone *tz); +extern int do_settimeofday(struct timespec *tv); +extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz); extern void clock_was_set(void); // call when ever the clock is set +extern int do_posix_clock_monotonic_gettime(struct timespec *tp); extern long do_nanosleep(struct timespec *t); extern long do_utimes(char __user * filename, struct timeval * times); #endif diff -urP -I '\$Id:.*Exp \$' -X /usr/src/patch.exclude linux-2.5.70-kb/kernel/posix-timers.c linux/kernel/posix-timers.c --- linux-2.5.70-kb/kernel/posix-timers.c 2003-05-30 01:18:19.000000000 -0700 +++ linux/kernel/posix-timers.c 2003-06-09 13:26:30.000000000 -0700 @@ -418,7 +418,7 @@ do { if (unlikely(!idr_pre_get(&posix_timers_id))) { error = -EAGAIN; - new_timer_id = (timer_t)-1; + new_timer->it_id = (timer_t)-1; goto out; } spin_lock_irq(&idr_lock); @@ -1035,8 +1035,7 @@ if (posix_clocks[which_clock].clock_set) return posix_clocks[which_clock].clock_set(&new_tp); - new_tp.tv_nsec /= NSEC_PER_USEC; - return do_sys_settimeofday((struct timeval *) &new_tp, NULL); + return do_sys_settimeofday(&new_tp, NULL); } asmlinkage long @@ -1202,6 +1201,7 @@ if (abs || !rq_time) { adjust_abs_time(&posix_clocks[which_clock], &t, abs, &rq_time); + // rq_time += (t.tv_sec || t.tv_nsec); } left = rq_time - get_jiffies_64(); diff -urP -I '\$Id:.*Exp \$' -X /usr/src/patch.exclude linux-2.5.70-kb/kernel/time.c linux/kernel/time.c --- linux-2.5.70-kb/kernel/time.c 2003-05-05 15:32:33.000000000 -0700 +++ linux/kernel/time.c 2003-05-30 01:29:48.000000000 -0700 @@ -63,28 +63,22 @@ /* * sys_stime() can be implemented in user-level using - * sys_settimeofday(). Is this for backwards compatibility? If so, + * sys_settimeofday(). Is this for backwards compatibility? If so, * why not move it into the appropriate arch directory (for those * architectures that need it). */ asmlinkage long sys_stime(int * tptr) { - int value; + struct timespec tv; if (!capable(CAP_SYS_TIME)) return -EPERM; - if (get_user(value, tptr)) + if (get_user(tv.tv_sec, tptr)) return -EFAULT; - write_seqlock_irq(&xtime_lock); - xtime.tv_sec = value; - xtime.tv_nsec = 0; - last_time_offset = 0; - time_adjust = 0; /* stop active adjtime() */ - time_status |= STA_UNSYNC; - time_maxerror = NTP_PHASE_LIMIT; - time_esterror = NTP_PHASE_LIMIT; - write_sequnlock_irq(&xtime_lock); + + tv.tv_nsec = 0; + do_settimeofday(&tv); return 0; } @@ -124,9 +118,11 @@ inline static void warp_clock(void) { write_seqlock_irq(&xtime_lock); + wall_to_monotonic.tv_sec -= sys_tz.tz_minuteswest * 60; xtime.tv_sec += sys_tz.tz_minuteswest * 60; last_time_offset = 0; write_sequnlock_irq(&xtime_lock); + clock_was_set(); } /* @@ -140,7 +136,7 @@ * various programs will get confused when the clock gets warped. */ -int do_sys_settimeofday(struct timeval *tv, struct timezone *tz) +int do_sys_settimeofday(struct timespec *tv, struct timezone *tz) { static int firsttime = 1; @@ -161,14 +157,14 @@ /* SMP safe, again the code in arch/foo/time.c should * globally block out interrupts when it runs. */ - do_settimeofday(tv); + return do_settimeofday(tv); } return 0; } asmlinkage long sys_settimeofday(struct timeval __user *tv, struct timezone __user *tz) { - struct timeval new_tv; + struct timespec new_tv; struct timezone new_tz; if (tv) { @@ -178,6 +174,7 @@ if (tz) { if (copy_from_user(&new_tz, tz, sizeof(*tz))) return -EFAULT; + new_tv.tv_nsec *= NSEC_PER_USEC; } return do_sys_settimeofday(tv ? &new_tv : NULL, tz ? &new_tz : NULL); diff -urP -I '\$Id:.*Exp \$' -X /usr/src/patch.exclude linux-2.5.70-kb/kernel/timer.c linux/kernel/timer.c --- linux-2.5.70-kb/kernel/timer.c 2003-05-30 01:18:19.000000000 -0700 +++ linux/kernel/timer.c 2003-05-30 01:29:48.000000000 -0700 @@ -1105,7 +1105,6 @@ asmlinkage long sys_sysinfo(struct sysinfo __user *info) { struct sysinfo val; - u64 uptime; unsigned long mem_total, sav_total; unsigned int mem_unit, bitcount; unsigned long seq; @@ -1113,11 +1112,25 @@ memset((char *)&val, 0, sizeof(struct sysinfo)); do { + struct timespec tp; seq = read_seqbegin(&xtime_lock); - uptime = jiffies_64 - INITIAL_JIFFIES; - do_div(uptime, HZ); - val.uptime = (unsigned long) uptime; + /* + * This is annoying. The below is the same thing + * posix_get_clock_monotonic() does, but it wants to + * take the lock which we want to cover the loads stuff + * too. + */ + + do_gettimeofday((struct timeval *)&tp); + tp.tv_nsec *= NSEC_PER_USEC; + tp.tv_sec += wall_to_monotonic.tv_sec; + tp.tv_nsec += wall_to_monotonic.tv_nsec; + if (tp.tv_nsec - NSEC_PER_SEC >= 0) { + tp.tv_nsec = tp.tv_nsec - NSEC_PER_SEC; + tp.tv_sec++; + } + val.uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); val.loads[0] = avenrun[0] << (SI_LOAD_SHIFT - FSHIFT); val.loads[1] = avenrun[1] << (SI_LOAD_SHIFT - FSHIFT);

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