by > Hello all,
> I have got an increasingly annoying problem with our fairly new (fall
> '02) Dual Athlon2k+ Gigabyte 7dpxdw linux system running 2.4.20.
> The only kernel patch applied is Alan Cox's ptrace patch.
is no such jumping on my system.
Try this program:
#include <stdio.h>
#include <time.h>
int main() {
time_t x,y;
(void)time(&x);
(void)time(&y);
for(;;) {
(void)time(&x);
if(x < y)
printf("Prev %ld New %ld\n", y, x);
y = x;
}
return 0;
If this shows time jumping around you have one of either:Quote:}
(1) Bad timer channel 0 chip (PIT).
(2) Some daemon trying to sync time with another system.
(3) You are traveling too close to the speed of light.
Now, your script shows time in fractional seconds.
You can modify the program to do this:Quote:> 1048608745.61 > 1048608745.60
#include <stdio.h>
#include <sys/time.h>
int main() {
struct timeval tv;
double x, y;
(void)gettimeofday(&tv, NULL);
x = (double) tv.tv_sec * 1e6;
x += (double) tv.tv_usec;
y = x;
for(;;) {
(void)gettimeofday(&tv, NULL);
x = (double) tv.tv_sec * 1e6;
x += (double) tv.tv_usec;
if(x < y)
printf("Prev %f New %f\n", y, x);
y = x;
}
return 0;
There should be no jumping around -- and there isn't onQuote:}
any system I've tested this on.
Hmmm, software should never crash. Even if the timers jump backwardsQuote:> Software crashes are regularly - naturally. No programmer expects system
> timers going back in time.
as you say, they should eventually time-out. If you have crashes, this
may point to other hardware problems as well.
Cheers,
* Johnson
Penguin : Linux version 2.4.20 on an i686 machine (797.90 BogoMips).
Why is the government concerned about the lunatic fringe? Think about it.
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