Re: [AD] proposal: al_sleep()

[aj <aj@xxxxxxxxxx>]

At 10:42 AM 2/01/2004 +0100, you wrote:
> On Fri, 2004-01-02 at 10:20, aj wrote:
>
> >
> > >So if I want 100% CPU, I don't call yield_timeslice.
> >
> >
> > correct.
> >
> >
> > >  If I have an idle
> > >loop,
> >
> >
> > yes,   and if you know you probably will not need CPU for X milliseconds,
> > then you should call  Sleep(X)  but be aware that X's minimum value is OS
> > dependant.
> > and you will have to consult the OS's documentation on its minimum 
> sleep time.
> >
> >
>
> Yes, so it would make sense for yield_timeslice to release CPU under
> windows and linux - even though it means, a complete timeslice is given
> up. All the patch does is replace Sleep(0) with Sleep(1) - and it
> achieves just that - CPU drops from 100% to 0%. If I'm in a loop where I
> need all the CPU power, I wouldn't call yield_timeslice - therefore the
> 10 ms I effectively lose don't matter. If I'm in an idle loop, and call
> yield_timeslice, I don't want the CPU to run with 100% - therefore
> giving up the timeslice with Sleep(1) makes more sense than keeping to
> run with 100% CPU with Sleep(0).


is sleep(1)  really 1 ms ?       on which system ?
sleep(1) can actually be more harmful than yield, due to thrashing.


if you know how much sleep you need then call sleep(>0) dont go trying to 
change the meaning of yield.




> And in Linux, my experience is that releasing CPU improves
> responsiveness of my programs compared to running on 100% CPU. (I can't
> explain why this would be the case though. Probably the linux scheduler
> penalties apps being 100% busy, and the sched_yield doesn't change
> anything in that.)



which linux scheduler ?    i dont know that much about the world of linux, 
but aren't there different schedulers out there ?
also, how can you say you get more responsiveness when its using less CPU.. 
thats a complete contradiction.