Re: [PATCH] Nick's scheduler policy

From: Nick Piggin
Date: Sun Aug 24 2003 - 22:07:04 EST




Felipe Alfaro Solana wrote:

On Sun, 2003-08-24 at 14:35, Nick Piggin wrote:

Hi,
Patch against 2.6.0-test4. It fixes a lot of problems here vs
previous versions. There aren't really any open issues for me, so
testers would be welcome.

The big change is more dynamic timeslices, which allows "interactive"
tasks to get very small timeslices while more compute intensive loads
can be given bigger timeslices than usual. This works properly with
nice (niced processes will tend to get bigger timeslices).

I think I have cured test-starve too.


I haven't still found any starvation cases, but forking time when the
system is under heavy load has increased considerable with respect to
vanilla or Con's O18.1int:

1. On a Konsole session, run "while true; do a=2; done"
2. Now, try forming a new Konsole session and you'll see it takes
approximately twice the time it takes when the system is under no load.


Yeah, it probably penalises parents and children too much on fork, and
doesn't penalise parents of exiting cpu hogs enough. I have noticed
this too.


Also, renicing X to -20 helps X interactivity, while with Con's patches,
renicing X to -20 makes it feel worse.


renicing IMO is a lot more sane in my patches, although others might
disagree. In Con's patches, when you make X -20, it gets huge timeslices.
In my version, it will get lots of smaller timeslices.

Thanks again for testing.

Nick

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/