Re: Can and should the kernel HZ value be changed?

Andrea Arcangeli (andrea@e-mind.com)
Mon, 4 Jan 1999 14:33:14 +0100 (CET)


On Sat, 2 Jan 1999, Steve Bergman wrote:

> The default value of HZ is 100hz. Since the DEF_PRIORITY in sched.h is 20, that

*snip*

> I'd like to find out more about it. Can anyone point me to more information or
> perhaps a previous discussion of this subject?

I know one point for which it's not good to leave the timer irq "slow" on
32bit machines. All linux timeout (starting from select, nanosleep, poll,
add_timer()) can be at most (~0UL>>1)-1 jiffies. If you increase the jiffy
speed the final result is that you'll be able to handle a very little
maximal timeout everywhere (if I remeber well going from 100 to 1000 you
goes from month to days).

Andrea Arcangeli

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/