Re: this_slice in kernel/sched.c?

From: Rik van Riel (riel@conectiva.com.br)
Date: Wed Oct 25 2000 - 09:34:48 EST


On Tue, 24 Oct 2000, Rasmus Andersen wrote:

> Reading through kernel/sched.c I came across this block (on line 597):
>
> {
> cycles_t t, this_slice;
>
> t = get_cycles();
> this_slice = t - sched_data->last_schedule;
> sched_data->last_schedule = t;
> }
>
> It seems to me that this_slice is somewhat unused in its scope and
> therefore I propose that the block is replaced by

> The fact that the scheduler probably have been examined many
> times by people far more knowledgeable that me makes the
> probability that this is wrong pretty big. In that case I would
> like to know what use this_slice has, if somebody would care to
> share.

this_slice was used in reschedule_idle(), to determine
whether it was worth it to interrupt the currently running
task or if it is better to wait a while until the currently
running task voluntarily reschedules.

The performance report by the Fujitsu guy (that was posted
here today) suggests that we really want to use the per-task
average time slice again to prevent cache thrashing...

regards,

Rik

--
"What you're running that piece of shit Gnome?!?!"
       -- Miguel de Icaza, UKUUG 2000

http://www.conectiva.com/ http://www.surriel.com/

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