2002-01-18 03:06:58

by Ed Tomlinson

[permalink] [raw]
Subject: o(1) to the rescue

Try this with and without the o(1) scheduler (J0).

Create a dir full of 1 meg or so jpegs. Fire up kde. Try using the Tools/Create image gallery.
With the standard scheduler linux is unusable - it stalls for most of the processing time for
each image. With o(1) its just a little jerky - still usable though (a gallery is building as I
type this).

Xmms playing to a arts server running with real time priority experienced no dropouts during
the process.

This is on 2.4.17 no preempt or low latency patches applied.

Real improvement - nice work,

Ed Tomlinson


2002-01-18 10:07:06

by Nero

[permalink] [raw]
Subject: Re: o(1) to the rescue

Ed Tomlinson wrote:

>Try this with and without the o(1) scheduler (J0).
>
>Create a dir full of 1 meg or so jpegs. Fire up kde. Try using the Tools/Create image gallery.
>With the standard scheduler linux is unusable - it stalls for most of the processing time for
>each image. With o(1) its just a little jerky - still usable though (a gallery is building as I
>type this).
>
>Xmms playing to a arts server running with real time priority experienced no dropouts during
>the process.
>
>This is on 2.4.17 no preempt or low latency patches applied.
>
>Real improvement - nice work,
>
>Ed Tomlinson
>-
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2002-01-18 10:21:47

by Helge Hafting

[permalink] [raw]
Subject: Re: o(1) to the rescue

Ed Tomlinson wrote:
>
> Try this with and without the o(1) scheduler (J0).
>
> Create a dir full of 1 meg or so jpegs. Fire up kde. Try using the
> Tools/Create image gallery.
> With the standard scheduler linux is unusable - it stalls for most of the
> processing time for
> each image. With o(1) its just a little jerky - still usable though (a
> gallery is building as I
> type this).

I guess this thing starts a thread per image? That would
give a lot of _running_ processes, which is exactly what
the O(1) scheduler improves.

Helge Hafting

2002-01-18 12:32:04

by Ed Tomlinson

[permalink] [raw]
Subject: Re: o(1) to the rescue

On January 18, 2002 05:21 am, Helge Hafting wrote:
> Ed Tomlinson wrote:
> > Try this with and without the o(1) scheduler (J0).
> >
> > Create a dir full of 1 meg or so jpegs. Fire up kde. Try using the
> > Tools/Create image gallery.
> > With the standard scheduler linux is unusable - it stalls for most of the
> > processing time for
> > each image. With o(1) its just a little jerky - still usable though (a
> > gallery is building as I
> > type this).
>
> I guess this thing starts a thread per image? That would
> give a lot of _running_ processes, which is exactly what
> the O(1) scheduler improves.

No. Just one thread running. I think its the fact that o(1) detects when
a task is no longer interactive. KDE is normally very interactive, when
building a gallery parts of it are not. o(1) detect this and adjusts itself.

This is on a UP K6-III 400 with 512M memory.

Ed Tomlinson