george anzinger <george@mvista.com> wrote:
>
> Andrew Morton wrote:
> > This should fix up the various mysterious application failures which people
> > have been seeing (xmms, mplayer, DB2 at least).
> >
> > A couple of things:
> >
> > - if (rq_time <= get_jiffies_64())
> > - return 0;
> >
> > That was unsafe against wrapping.
>
> Uh, I don't think so. They are both 64 bits. It that wraps we will
> both be long gone ...
Well, someome may decide to set INTIAL_JIFFIES to -300HZ. It is more
correct.
> > Also I think this calculation:
> >
> > - if (abs || !rq_time){
> > - adjust_abs_time(&posix_clocks[which_clock], &t, abs);
> >
> > - tstojiffie(&t, posix_clocks[which_clock].res, &rq_time);
> > - }
> >
> > should be outside the loop, yes?
>
> No. If abs is set we need to redue the conversion just in case the
> clock was set (and setting the clock will wake us up early). If abs
> is not set, we just do the conversion once, after which rq_time will
> be non-zero and we will use the old expire time.
OK. Here's an updated patch.
kernel/posix-timers.c | 44 ++++++++++++++++++++------------------------
1 files changed, 20 insertions(+), 24 deletions(-)
diff -puN kernel/posix-timers.c~posix-timers-fixes kernel/posix-timers.c
--- 25/kernel/posix-timers.c~posix-timers-fixes 2003-03-19 22:56:25.000000000 -0800
+++ 25-akpm/kernel/posix-timers.c 2003-03-20 00:15:17.000000000 -0800
@@ -182,8 +182,7 @@ init_posix_timers(void)
__initcall(init_posix_timers);
-static inline int
-tstojiffie(struct timespec *tp, int res, u64 *jiff)
+static void tstojiffie(struct timespec *tp, int res, u64 *jiff)
{
unsigned long sec = tp->tv_sec;
long nsec = tp->tv_nsec + res - 1;
@@ -212,17 +211,14 @@ tstojiffie(struct timespec *tp, int res,
* Split to jiffie and sub jiffie
*/
*jiff += nsec / (NSEC_PER_SEC / HZ);
- /*
- * We trust that the optimizer will use the remainder from the
- * above div in the following operation as long as they are close.
- */
- return 0;
}
+
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, &result);
timer->it_timer.expires = (unsigned long)result;
tstojiffie(&time->it_interval, res, &result);
@@ -1195,6 +1191,7 @@ sys_clock_nanosleep(clockid_t which_cloc
return ret;
}
+
long
do_clock_nanosleep(clockid_t which_clock, int flags, struct timespec *tsave)
{
@@ -1225,41 +1222,40 @@ do_clock_nanosleep(clockid_t which_clock
rq_time = (rq_time << 32) + restart_block->arg2;
if (!rq_time)
return -EINTR;
- if (rq_time <= get_jiffies_64())
- return 0;
+ left = rq_time - get_jiffies_64();
+ if (left <= 0LL)
+ return 0; /* Already passed */
}
if (abs && (posix_clocks[which_clock].clock_get !=
posix_clocks[CLOCK_MONOTONIC].clock_get)) {
add_wait_queue(&nanosleep_abs_wqueue, &abs_wqueue);
}
+
do {
t = *tsave;
- if (abs || !rq_time){
+ if (abs || !rq_time) {
adjust_abs_time(&posix_clocks[which_clock], &t, abs);
-
tstojiffie(&t, posix_clocks[which_clock].res, &rq_time);
}
-#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;
- }
- current->state = TASK_INTERRUPTIBLE;
+
+ left = rq_time - get_jiffies_64();
+ if (left >= MAX_JIFFY_OFFSET)
+ left = MAX_JIFFY_OFFSET;
+ if (left < 0)
+ break;
+
+ new_timer.expires = jiffies + left;
+ __set_current_state(TASK_INTERRUPTIBLE);
add_timer(&new_timer);
schedule();
del_timer_sync(&new_timer);
left = rq_time - get_jiffies_64();
- }
- while ( (left > 0) &&
- !test_thread_flag(TIF_SIGPENDING));
+ } while (left > 0 && !test_thread_flag(TIF_SIGPENDING));
- if( abs_wqueue.task_list.next)
+ if (abs_wqueue.task_list.next)
finish_wait(&nanosleep_abs_wqueue, &abs_wqueue);
if (left > 0) {
_
-
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This archive was generated by hypermail 2b29 : Sun Mar 23 2003 - 22:00:30 EST