lkml.org 
[lkml]   [1998]   [Jan]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Scheduler latency
On Wed, 21 Jan 1998, Linus Torvalds wrote:

>
>
> On Wed, 21 Jan 1998, Jauder Ho wrote:
> >
> > benchsrv%jauderho% uname -a ; ./a.out
> > Linux benchsrv.transmeta.com 2.1.62 #5 Mon Nov 3 15:36:46 PST 1997 i686
> > Timing 1000 iterations of sched_yield(2) in class SCHED_OTHER
> > Total time: 42874 us iteration time: 42 us
>
> The above is a dual SMP..

AFAIK I remember it being a single. And I remember setting it up :)

>
> As is sw130..

it is SMP

> But "marvin" is a single, right?

it is a single, but so is my home machine. which gives

turtle%jauderho% ./a.out
Timing 1000 iterations of sched_yield(2) in class SCHED_OTHER
Total time: 45862 us iteration time: 45 us

however it seems to isolated to marvin only which is kinda strange..,
coz sodium which is another single running 2.1.80 returns

calcium%i386-linux% rsh na ./a.out
Timing 1000 iterations of sched_yield(2) in class SCHED_OTHER
Total time: 39899 us iteration time: 39 us

marvin and turtle are compiled as UP, right. I have had problems with SMP
kernels not liking the fact that i have a SMP board with only one cpu.

--Jauder

> No, there should be almost no difference between what you run on marvin
> and what runs on sw130 (apart from the SMP irq stuff, but the fact that
> you can run at all on marvin means that you compiled marvin as UP,
> right?). BUT sw130 is a dual, which allows us to schedule one process on
> one CPU and run another on the other - they can actually partly overlap.
> That would certainly explain the difference in times..
>

ADVISORY: There Is an Extremely Small but Nonzero Chance That, Through a
Process Known as 'Tunneling,' This Message May Spontaneously Disappear
from Its Present Location and Reappear at Any Random Place in the
Universe, Including Your Neighbour's Kitchen. The Author Will Not Be
Responsible for Any Damages or Inconveniences That May Result.


\
 
 \ /
  Last update: 2005-03-22 13:41    [from the cache]
©2003-2011 Jasper Spaans