Re: [PATCH]O14int

[Con Kolivas]

On Mon, 11 Aug 2003 19:15, Nick Piggin wrote:
> Con Kolivas wrote:
> >On Mon, 11 Aug 2003 15:44, Martin Schlemmer wrote:
> >>On Sat, 2003-08-09 at 11:04, Con Kolivas wrote:
> >>>On Sat, 9 Aug 2003 01:49, Con Kolivas wrote:
> >>>>More duck tape interactivity tweaks
> >>>
> >>>s/duck/duct
> >>>
> >>>>Wli pointed out an error in the nanosecond to jiffy conversion which
> >>>>may have been causing too easy to migrate tasks on smp (? performance
> >>>>change).
> >>>
> >>>Looks like I broke SMP build with this. Will fix soon; don't bother
> >>>trying this on SMP yet.
> >>
> >>Not to be nasty or such, but all these patches have taken
> >>a very responsive HT box to one that have issues with multiple
> >>make -j10's running and random jerkyness.
> >
> >A UP HT box you mean? That shouldn't be capable of running multiple make
> > -j10s without some noticable effect. Apart from looking impressive, there
> > is no point in having 30 cpu heavy things running with only 1 and a bit
> > processor and the machine being smooth as silk; the cpu heavy things will
> > just be unfairly starved in the interest of appearance (I can do that
> > easily enough). Please give details if there is a specific issue you
> > think I've broken or else I wont know about it.
>
> Yeah make -j10s won't be without impact, but I think for a lot of
> interactive stuff they don't need a lot of CPU, just to get it
> in a timely manner. And Martin did say it had been responsive.
> Sounds like in this case your changes are causing the interactive
> stuff to get less CPU or higher scheduling latency?

Sigh..,

No, it sounds to me like things are expiring faster than on default. He didn't 
say make -j10, it was multiple -j10s. This is one where you simply cannot let 
the scheduler keep starving the make -j10s indefinitely for X; on a server or 
multiuser box X will simply cause unfair starvation. I'm trying to find a 
workaround for this without rewriting whole sections of the scheduler code, 
but I'm just not sure I should be trying to optimise for a desktop that runs 
loads >16 per cpu. (I'll keep trying though, but if there is no workaround 
that remains fair it wont happen)

Con

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