Re: Dosemu and clipper applications eating all CPU

[Maurilio Longo <maurilio.longo@libero.it>]

Stas,


> > it probably depends on the linker used to create the clipper app, here
> > we use blinker to create a protect mode application
> Yes, the prog I now have, also uses
> blinker.
> Btw, in both dosemu-1.2.1 and 1.3.0
> it works only in real mode since the
> proper Blinker support was added only
> in 1.3.1. Does your prog work in real
> or protected mode for you?
>

it is in protect mode, I don't know if it could run at all in real mode.


> > In 1.1.3 (which is the dosemu we use)
> 1.1.3 is too old and buggy. Why are you
> still using it? 1.3.0 or 1.3.1 should
> be much better.
>

I've switched to 1.2.1 the other day and set hog_threshold to 45, but it uses
nearly 60% of cpu while completely idle (lower values make serial transmission
stop working) and 99% of cpu while inside dos prompt.

>
> > I had to make the changes I told you, and I
> > use hog_threshold(0) to have the clipper app to give back all the time
> > it doesn't use.
> OK, but not everything is clear.
> You said you call usleep() every 50th
> call and set $_hogthreshold=(0).
> But then, if you set $_hogthreshold=(1)
> with an unmodified dosemu, it should
> call usleep() on *every* call of int21/ah=2c,
> so it must release much more CPU time!
> How it happens that it doesn't?
> (please see int.c line 1201, where 0x2c
> is trapped).
> -

Yes, it _does_ and this makes our clipper program unresponsive to user
commands, so I changed INT2F_ to INT28_IDLE_SEC and it was better but not
enough, so I put the 50 calls per usleep() hack, and this way it is responsive
and cpu is around 1, 2%.

But the problem, in my opinion is that usleep() sleeps a fixed amount of time
(either INT2F_IDLE_SEC or INT28_IDLE_SEC) while it should simply (if at all
possible on linux) give back the rest of current time slice, this way if it
has someting to do for, let's say,  1/10th of its time slice, it does it and
then gives 9/10th back to linux instead of sleeping for a certain _fixed_
amount of time.

regards.


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