> > I've just noticed a bug with having my scheduler set to 1000Hz (by editing
> > /usr/src/linux/include/asm/param.h, of course). Although scheduling does,
> > in fact, seem smoother, ps returns that a process has been running longer
> > than it really has; in fact, it's by exactly a factor of 10, go figure.
> > Just to prove this, I ran the following simple script (PID 1097 is,
> > obviously, rc5des):
>
> That is elementary. The running time counts are in JIFFIES,
> which are in the HZ units. The 'ps' has 'HZ' compiled in
> when it was made. In fact the system does not tell the internal
> HZ value out in any easy to use way. So sad.
Ah, I see... is there any way for the ps/top/etc. utilities to get at the
HZ rate so this behaviour can be fixed?
> $ cat /proc/interrupts |grep timer;sleep 1;cat /proc/interrupts |grep timer
> 8: 75924461 timer
> 8: 75925508 timer
>
> The delta is 1047 interrupts; HZ at the machine is 1024...
Yeah, this makes sense, definitely. I suppose a ps binary could try to
work out the jiffy rate from that, but it'd be inaccurate at best (mine at
1000 returns 1013 interrupts).
I guess I can just deal with it and remember to divide by 10.
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