Andrew Morton wrote:
> george anzinger <george@mvista.com> wrote:
>
>>Ok, here is what I have. I changed nano sleep to use a local 64-bit
>>value for the target expire time in jiffies. As much as MAX-INT/2-1
>>will be put in the timer at any one time. It loops till the target
>>time is met or exceeded. The changes affect (clock)nanosleep only and
>>not timers (they still error out for large values).
>
>
> Seem sane.
>
>
>>I now use the simple u64=(long long) a * b for the mpy so I have
>>dropped the sc_math.h stuff (I will bring that round again :).
>
>
> Resistance shall be unflagging!
>
>
>>What do you think?
>
>
> Sorry, but this little bit:
>
> while ((active = del_timer_sync(&new_timer) ||
> rq_time > get_jiffies_64()) &&
> !test_thread_flag(TIF_SIGPENDING));
>
>
> if (abs_struct.list.next) {
> spin_lock_irq(&nanosleep_abs_list_lock);
> list_del(&abs_struct.list);
> spin_unlock_irq(&nanosleep_abs_list_lock);
> }
> if (active) {
>
> should be dragged out and mercifully shot. Is it possible to make that while
> loop a little clearer?
I hung it! It was less of a mess to clean up :)
>
> The abs_list exactly duplicates the kernel's existing waitqueue
> functionality. You can use prepare_to_wait()/finish_wait() there.
Well, almost. Wants to mess with the state, but, try the attached.
>
> posix_timers_id, posix_clocks[], nanosleep_abs_list_lock and
> nanosleep_abs_list should be static to posix-timers.c.
And a few more :)
-- 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-2.5.64-kb/include/linux/thread_info.h linux/include/linux/thread_info.h --- linux-2.5.64-kb/include/linux/thread_info.h 2002-12-11 06:25:32.000000000 -0800 +++ linux/include/linux/thread_info.h 2003-03-10 16:39:52.000000000 -0800 @@ -12,7 +12,7 @@ */ struct restart_block { long (*fn)(struct restart_block *); - unsigned long arg0, arg1, arg2; + unsigned long arg0, arg1, arg2, arg3; }; extern long do_no_restart_syscall(struct restart_block *parm); diff -urP -I '\$Id:.*Exp \$' -X /usr/src/patch.exclude linux-2.5.64-kb/kernel/posix-timers.c linux/kernel/posix-timers.c --- linux-2.5.64-kb/kernel/posix-timers.c 2003-03-12 01:57:56.000000000 -0800 +++ linux/kernel/posix-timers.c 2003-03-12 02:04:31.000000000 -0800 @@ -9,7 +9,6 @@ /* These are all the functions necessary to implement * POSIX clocks & timers */ - #include <linux/mm.h> #include <linux/smp_lock.h> #include <linux/interrupt.h> @@ -23,6 +22,7 @@ #include <linux/compiler.h> #include <linux/idr.h> #include <linux/posix-timers.h> +#include <linux/wait.h> #ifndef div_long_long_rem #include <asm/div64.h> @@ -56,8 +56,8 @@ * Lets keep our timers in a slab cache :-) */ static kmem_cache_t *posix_timers_cache; -struct idr posix_timers_id; -spinlock_t idr_lock = SPIN_LOCK_UNLOCKED; +static struct idr posix_timers_id; +static spinlock_t idr_lock = SPIN_LOCK_UNLOCKED; /* * Just because the timer is not in the timer list does NOT mean it is @@ -130,7 +130,7 @@ * which we beg off on and pass to do_sys_settimeofday(). */ -struct k_clock posix_clocks[MAX_CLOCKS]; +static struct k_clock posix_clocks[MAX_CLOCKS]; #define if_clock_do(clock_fun, alt_fun,parms) (! clock_fun)? alt_fun parms :\ clock_fun parms @@ -183,7 +183,7 @@ __initcall(init_posix_timers); static inline int -tstojiffie(struct timespec *tp, int res, unsigned long *jiff) +tstojiffie(struct timespec *tp, int res, u64 *jiff) { unsigned long sec = tp->tv_sec; long nsec = tp->tv_nsec + res - 1; @@ -203,7 +203,7 @@ * below. Here it is enough to just discard the high order * bits. */ - *jiff = HZ * sec; + *jiff = (u64)sec * HZ; /* * Do the res thing. (Don't forget the add in the declaration of nsec) */ @@ -221,9 +221,12 @@ static void tstotimer(struct itimerspec *time, struct k_itimer *timer) { + u64 result; int res = posix_clocks[timer->it_clock].res; - tstojiffie(&time->it_value, res, &timer->it_timer.expires); - tstojiffie(&time->it_interval, res, &timer->it_incr); + tstojiffie(&time->it_value, res, &result); + timer->it_timer.expires = (unsigned long)result; + tstojiffie(&time->it_interval, res, &result); + timer->it_incr = (unsigned long)result; } static void @@ -1020,6 +1023,9 @@ * Note also that the while loop assures that the sub_jiff_offset * will be less than a jiffie, thus no need to normalize the result. * Well, not really, if called with ints off :( + + * HELP, this code should make an attempt at resolution beyond the + * jiffie. Trouble is this is "arch" dependent... */ int @@ -1127,26 +1133,14 @@ * holds (or has held for it) a write_lock_irq( xtime_lock) and is * called from the timer bh code. Thus we need the irq save locks. */ -spinlock_t nanosleep_abs_list_lock = SPIN_LOCK_UNLOCKED; -struct list_head nanosleep_abs_list = LIST_HEAD_INIT(nanosleep_abs_list); +static DECLARE_WAIT_QUEUE_HEAD(nanosleep_abs_wqueue); -struct abs_struct { - struct list_head list; - struct task_struct *t; -}; void clock_was_set(void) { - struct list_head *pos; - unsigned long flags; - - spin_lock_irqsave(&nanosleep_abs_list_lock, flags); - list_for_each(pos, &nanosleep_abs_list) { - wake_up_process(list_entry(pos, struct abs_struct, list)->t); - } - spin_unlock_irqrestore(&nanosleep_abs_list_lock, flags); + wake_up_all(&nanosleep_abs_wqueue); } long clock_nanosleep_restart(struct restart_block *restart_block); @@ -1201,19 +1195,19 @@ return ret; } - long do_clock_nanosleep(clockid_t which_clock, int flags, struct timespec *tsave) { struct timespec t; struct timer_list new_timer; - struct abs_struct abs_struct = { .list = { .next = 0 } }; + DECLARE_WAITQUEUE(abs_wqueue, current); + u64 rq_time = 0; + s64 left; int abs; - int rtn = 0; - int active; struct restart_block *restart_block = ¤t_thread_info()->restart_block; + abs_wqueue.flags = 0; init_timer(&new_timer); new_timer.expires = 0; new_timer.data = (unsigned long) current; @@ -1226,54 +1220,50 @@ * time and continue. */ restart_block->fn = do_no_restart_syscall; - if (!restart_block->arg2) - return -EINTR; - new_timer.expires = restart_block->arg2; - if (time_before(new_timer.expires, jiffies)) + rq_time = restart_block->arg3; + rq_time = (rq_time << 32) + restart_block->arg2; + if (!rq_time) + return -EINTR; + if (rq_time <= get_jiffies_64()) return 0; } if (abs && (posix_clocks[which_clock].clock_get != posix_clocks[CLOCK_MONOTONIC].clock_get)) { - spin_lock_irq(&nanosleep_abs_list_lock); - list_add(&abs_struct.list, &nanosleep_abs_list); - abs_struct.t = current; - spin_unlock_irq(&nanosleep_abs_list_lock); + add_wait_queue(&nanosleep_abs_wqueue, &abs_wqueue); } do { t = *tsave; - if ((abs || !new_timer.expires) && - !(rtn = adjust_abs_time(&posix_clocks[which_clock], - &t, abs))) { - /* - * On error, we don't set up the timer so - * we don't arm the timer so - * del_timer_sync() will return 0, thus - * active is zero... and so it goes. - */ + if (abs || !rq_time){ + adjust_abs_time(&posix_clocks[which_clock], &t, abs); - tstojiffie(&t, - posix_clocks[which_clock].res, - &new_timer.expires); + tstojiffie(&t, posix_clocks[which_clock].res, &rq_time); } - if (new_timer.expires) { - current->state = TASK_INTERRUPTIBLE; - add_timer(&new_timer); - - schedule(); +#if (BITS_PER_LONG < 64) + if ((rq_time - get_jiffies_64()) > MAX_JIFFY_OFFSET){ + new_timer.expires = MAX_JIFFY_OFFSET; + }else +#endif + { + new_timer.expires = (long)rq_time; } - } - while ((active = del_timer_sync(&new_timer)) && - !test_thread_flag(TIF_SIGPENDING)); + current->state = TASK_INTERRUPTIBLE; + add_timer(&new_timer); + + schedule(); - if (abs_struct.list.next) { - spin_lock_irq(&nanosleep_abs_list_lock); - list_del(&abs_struct.list); - spin_unlock_irq(&nanosleep_abs_list_lock); + del_timer_sync(&new_timer); + left = rq_time - get_jiffies_64(); } - if (active) { - long jiffies_left; + while ( (left > 0) && + !test_thread_flag(TIF_SIGPENDING)); + + if( abs_wqueue.task_list.next) + finish_wait(&nanosleep_abs_wqueue, &abs_wqueue); + + if (left > 0) { + unsigned long rmd; /* * Always restart abs calls from scratch to pick up any @@ -1282,29 +1272,19 @@ if (abs) return -ERESTARTNOHAND; - jiffies_left = new_timer.expires - jiffies; - - if (jiffies_left < 0) - return 0; - - jiffies_to_timespec(jiffies_left, tsave); + tsave->tv_sec = div_long_long_rem(left, HZ, &rmd); + tsave->tv_nsec = rmd * (NSEC_PER_SEC / HZ); - while (tsave->tv_nsec < 0) { - tsave->tv_nsec += NSEC_PER_SEC; - tsave->tv_sec--; - } - if (tsave->tv_sec < 0) { - tsave->tv_sec = 0; - tsave->tv_nsec = 1; - } restart_block->fn = clock_nanosleep_restart; restart_block->arg0 = which_clock; restart_block->arg1 = (unsigned long)tsave; - restart_block->arg2 = new_timer.expires; + restart_block->arg2 = rq_time & 0xffffffffLL; + restart_block->arg3 = rq_time >> 32; + return -ERESTART_RESTARTBLOCK; } - return rtn; + return 0; } /* * This will restart either clock_nanosleep or clock_nanosleep
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This archive was generated by hypermail 2b29 : Sat Mar 15 2003 - 22:00:30 EST