Re: HZ, preferably as small as possible

Lincoln Dale
2002-07-11T00:26:57Z

At 02:28 PM 10/07/2002 -0700, Andrew Morton wrote:
> > But on the other hand, increasing HZ has perf/latency benefits, yes? Have
> > these been quantified?
>
>Not that I'm aware of. And I'd regard any such claims with some
>scepticism.

for one, i'm using a modified version of the network FIFO queue discipline
to inject "delay" and "drop", similar to what ippipe can do on FreeBSD.
given i'm using a kernel timer for this, HZ >= 1000 is essential for <1.5
millisecond accuracy.

perhaps we really need a high-speed timer mechanism for parts of the kernel
that require it (or a highly-accurate single-fire timer)?

cheers,

lincoln.