Re: HZ, preferably as small as possible

[Martin Dalecki <dalecki@evision-ventures.com>]

Użytkownik Thunder from the hill napisał:
> Hi,
> 
> On Thu, 11 Jul 2002, Hannu Savolainen wrote:
> 
>>This is not a problem at all. Just define HZ as:
>>
>>extern int system_hz;
>>#define HZ system_hz
>>
>>After that all code will use variable HZ. Changing HZ on fly will be
>>dangerous. However HZ can be made a boot time (LILO) parameter.
> 
> 
> OK, that's probably a start. As the next step, I'd recommend that the 
> maintainers and their supporters try to replace the static HZ with 
> possibly-dynamic system_hz. The third step would be to have guys like Ingo 
> to tune system_hz to be really dynamic.
> 
> Cool idea, anyway.

Just remember plase to map it to /proc/sys/kernel/xxx
So we could implement the following properly:

_SC_CLK_TCK            CLK_TCK       Ticks per second          (clock_t)

(Taken from Solaris pecs.)

Unless of course we stick to the fact that HZ exposed
to user land remains an arch specific constant as in 2.5.25 which
I think is the more prefferable solution.

Pitty is RedHat beta does mess with this! The 2.5.25 solutoin from
Linus is far better.