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SubjectRe: [PATCH] scheduler fixups ...
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Davide Libenzi <davidel@xmailserver.org> writes:

> On 2 Jan 2002, Peter Osterlund wrote:
>
> > Davide Libenzi <davidel@xmailserver.org> writes:
> >
> > > a still lower ts
> >
> > This also lowers the effectiveness of nice values. In 2.5.2-pre6, if I
> > run two cpu hogs at nice values 0 and 19 respectively, the niced task
> > will get approximately 20% cpu time (on x86 with HZ=100) and this
> > patch will give even more cpu time to the niced task. Isn't 20% too
> > much?
>
> The problem is that with HZ == 100 you don't have enough granularity to
> correctly scale down nice time slices. Shorter time slices helps the
> interactive feel that's why i'm pushing for this.

OK, but even architectures with bigger HZ values will suffer. Isn't it
better to set MIN_NICE_TSLICE to a smaller value (such as 1000) and
fix the calculation in fill_tslice_map to make sure ts_table[i] is
always non-zero. The current formula will break anyway if

HZ < 1000000 / MIN_NICE_TSLICE = 100,

but maybe HZ >= 100 is true for all architectures?

--
Peter Osterlund - petero2@telia.com
http://w1.894.telia.com/~u89404340
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