Re: Kern.hz= +1 hertz at anything 2500 and above.

I haven't done much messing with scheduling. It is set at the default ULE
for this machine.



On Thu, Jul 25, 2013 at 12:11 PM, Adrian Chadd <adrian_at_freebsd.org> wrote:

> On 25 July 2013 02:51, Wojciech Puchar <wojtek_at_wojtek.tensor.gdynia.pl>
> wrote:
> >> improved with a higher kern.hz rating. Unless the future holds an
> emu20k2,
> >> there will be RAM used from the motherboard.
> >> 1. I will need a real-time or a faster kernel- hence the high rate
> wanted-
> >> because the devices to be built will be used in an active environment:
> >> art,
> >> music, audio control.
> >> 2. Any system with limited memory and a low CPU hertz rate benefits from
> >> the higher kern.hz setting.
>
> > rather opposite. more kern.hz=more interrupts.
>
> Right.
>
> More hz == more interrupts and less ability for a CPU-bound process to
> chew all the CPU.
>
> So is it a scheduling issue, where you have multiple CPU bound
> userland processes that aren't being fair and consuming all the CPU?
> Is it that your device driver(s) aren't interrupting correctly,
> relying on the hz tick to make up the slack, etc.
>
> Is it a busted halt loop, which is being papered over with hz ticks?
>
> Have you tried -10 on that kit, with the more aggressive clock/timer
> code that won't interrupt unless it needs to? Has that changed things?
>
>
>
> -adrian
>