Re: [PATCH] O3int interactivity for 2.5.74-mm2

From: Con Kolivas <kernel@kolivas.org>
To: Felipe Alfaro Solana <felipe_alfaro@linuxmail.org>
Cc: linux kernel mailing list <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@osdl.org>
Subject: Re: [PATCH] O3int interactivity for 2.5.74-mm2
Date: Mon, 7 Jul 2003 07:17:13 +1000	[thread overview]
Message-ID: <200307070717.13951.kernel@kolivas.org> (raw)
In-Reply-To: <1057516609.818.4.camel@teapot.felipe-alfaro.com>

On Mon, 7 Jul 2003 04:36, Felipe Alfaro Solana wrote:
> On Sun, 2003-07-06 at 19:16, Con Kolivas wrote:
> > -----BEGIN PGP SIGNED MESSAGE-----
> > Hash: SHA1
> >
> > Attached is an incremental patch against 2.5.74-mm2 with more
> > interactivity work. Audio should be quite resistant to skips with this,
> > and it should not induce further unfairness.
> >
> > Changes:
> > The sleep_avg buffer was not needed with the improved semantics in O2int
> > so it has been removed entirely as it created regressions in O2int.
> >
> > A small change to the idle detection code to only make tasks with enough
> > accumulated sleep_avg become idle.
> >
> > Minor cleanups and clarified code.
> >
> >
> > Other issues:
> > Jerky mouse with heavy page rendering in web browsers remains. This is a
> > different issue to the audio and will need some more thought.
> >
> > The patch is also available for download here:
> > http://kernel.kolivas.org/2.5
> >
> > Note for those who wish to get smooth X desktop feel now for their own
> > use, the granularity patch on that website will do wonders on top of
> > O3int, but a different approach will be needed for mainstream
> > consumption.
>
> I'm seeing extreme X starvation with this patch under 2.5.74-mm2 when
> starting a CPU hogger:
>
> 1. Start a KDE session.
> 2. Launch a Konsole
> 3. Launch Konqueror
> 4. Launch XMMS
> 5. Make XMMS play an MP3 file
> 6. On the Konsole terminal, run "while true; do a=2; done"
>
> When the "while..." is run, X starves completely for ~5 seconds (e.g.
> the mouse cursor doesn't respond to my input events). After those 5
> seconds, the mouse cursor goes jerky for a while (~2 seconds) and then
> the system gets responsive.

Oh one more thing if you dare. Try commenting out these lines in sched.c ~650:

	normalise_sleep(p);
	normalise_sleep(p->parent);
 	if (p->sleep_avg < p->parent->sleep_avg)
 		p->parent->sleep_avg = (p->parent->sleep_avg * EXIT_WEIGHT +
 			p->sleep_avg) / (EXIT_WEIGHT + 1);

Con