Can I influence the scheduler ?

Can I influence the scheduler ?

Post by Markus Grunwal » Sat, 14 Dec 2002 03:04:55



Hello,

I have some kind of embedded system (ARM architecture). Someone decided
NOT to install a real time linux but a "normal" one and I have to live
with it.

Now I have a routine which shold run as fast as it can, i.e. without
interruption if possible... Are there any possibilities ? Every hint is
welcome !

cu
--
Markus Grunwald

Registered Linux User Nr 101577      http://www.grunwald.2xs.de
http://counter.li.org                (hier pgp/gpg public key)

 
 
 

Can I influence the scheduler ?

Post by Lew Pitch » Sat, 14 Dec 2002 03:40:59




Quote:>Hello,

>I have some kind of embedded system (ARM architecture). Someone decided
>NOT to install a real time linux but a "normal" one and I have to live
>with it.

>Now I have a routine which shold run as fast as it can, i.e. without
>interruption if possible... Are there any possibilities ? Every hint is
>welcome !

Hint: nice(2)

Lew Pitcher
IT Consultant, Development Services
Toronto Dominion Bank Financial Group

(Opinions expressed are my own, not my employers')

 
 
 

Can I influence the scheduler ?

Post by Sundial Service » Sat, 14 Dec 2002 04:02:15



> Hello,

> I have some kind of embedded system (ARM architecture). Someone decided
> NOT to install a real time linux but a "normal" one and I have to live
> with it.

> Now I have a routine which shold run as fast as it can, i.e. without
> interruption if possible... Are there any possibilities ? Every hint is
> welcome !

Give the process a superior priority and it will probably run when the
interrupt happens.  I say "probably" because it can be pre-empted by other
still more important processes.

Handle any "at interrupt time" stuff in the interrupt handler but keep that
to a minimum.

 
 
 

Can I influence the scheduler ?

Post by Nils O. Sel?sd » Sat, 14 Dec 2002 05:10:49


Quote:> Hello,

> I have some kind of embedded system (ARM architecture). Someone decided
> NOT to install a real time linux but a "normal" one and I have to live
> with it.

> Now I have a routine which shold run as fast as it can, i.e. without
> interruption if possible... Are there any possibilities ? Every hint is
> welcome !

Man sched_setcheduler. You can use one of the "realtime"
schedulers(Round Robin or FIFO scheduler)
I wrote some tools http://www.sourceforge.net/projects/schedutils
that works pretty much like (re)nice but affect these schedulers
instead, look at the code there.

--
Vennlig hilsen/Best Regards
Nils Olav Sel?sdal
System Engineer
UtelSystems a/s

 
 
 

Can I influence the scheduler ?

Post by Nils O. Sel?sd » Sat, 14 Dec 2002 05:13:58


Quote:>> welcome !
> Man sched_setcheduler. You can use one of the "realtime"

man sched_setscheduler that is :/

--
Vennlig hilsen/Best Regards
Nils Olav Sel?sdal
System Engineer
UtelSystems a/s

 
 
 

Can I influence the scheduler ?

Post by Markus Grunwal » Sun, 15 Dec 2002 23:39:40


Hello,

Quote:> > Now I have a routine which shold run as fast as it can, i.e. without
> > interruption if possible... Are there any possibilities ? Every hint
> > is welcome !
> Man sched_setcheduler. You can use one of the "realtime"
> schedulers(Round Robin or FIFO scheduler)

That's what I wanted. Many, many thanks !

Quote:> I wrote some tools http://www.sourceforge.net/projects/schedutils
> that works pretty much like (re)nice but affect these schedulers
> instead, look at the code there.

I'll look at it (next week). But the sched_setscheduler call seems quite
straightforward to me.

Perhaps you can help me with one paragraph from the manpage:

"[...] a software developer should always keep available on the console
a shell scheduled under a higher static priority than the tested
application."

Ok, I understand this. But how can I tell my bash to do this ? IMHO I'll
have to change the source of bash  8-O ... ?

Another thing: There is one "black box" kernel mode driver which reads
data from a analog-digital-converter (ADC) on my machine. If I
understood correctly, I could block this driver if I am not carefull ?

Thanks again,
--
Markus Grunwald

Registered Linux User Nr 101577      http://www.grunwald.2xs.de
http://counter.li.org                (hier pgp/gpg public key)