Re: 2.5.47 scheduler problems?

Mike Galbraith
2002-11-18T07:28:21Z

----- Original Message -----
From: "Tim Connors" <tconnors@astro.swin.edu.au>
To: <linux-kernel@vger.kernel.org>; "Mike Galbraith" <efault@gmx.de>
Sent: Monday, November 18, 2002 7:51 AM
Subject: Re: 2.5.47 scheduler problems?

> In linux.kernel, you wrote:
> > Greetings,
> >
> > For testing swap throughput, I like to run make -j30 bzImage on my
500Mhz
> > PIII w. 128Mb ram. For testing interactivity, I fire up KDE, start
a
> > smaller make -j, grab a window, and wave it around.
> >
> > With 2.4.20rc2+rc1aa1, running a -j10 build (not swapping) is very
very
> > bad. However, if I set all tasks in the system to SCHED_FIFO or
SCHED_RR
> > prior to this light make -j, I have a ~pretty smooth system.
> >
> > If I do the same in 2.5.47, I have no control of my box. Setting
all tasks
> > to SCHED_FIFO or SCHED_RR prior to starting make -j10 bzImage, I can
regain
> > control, but interactivity under load is basically not present.
>
> Funny that.
>
> > I used to be able to wave a window poorly at make -j25 (swapping
heftily),
> > fairly smoothly at make -j20, and smoothly at make -j15 or below.
This
> > with no SCHED_RR/SCHED_FIFO. (I haven't done much testing like this
in
> > quite a while though)
>
> Perhaps you should consider buying an extra 29 CPU's for you desktop?

I have neither the need for 30 CPUs, nor the cash to pay for such a
beast :)

I gather you think my test is silly?

-Mike