From: Jean-Luc Dery (dery++at++discreet.com)
Date: 04/03/2000 09:33:04
On Apr 3, 8:21am, Angus Dorbie wrote:
> Subject: Re: Draw lock-up
> Sounds like you are either oversubscribing texture memory or suddenly
> drawing many new elements of the database with texture on them for the
> first time forcing a significant download overhead.
We have encountered a similar problems. The cause appears to be related to
texture paging. This has been noticed on Octane and Onyx2's so far. I will be
investigating the Onyx1 - 16MB TRAM today.
The traces from the Onyx2 platform are the following:
> 0 inInterval(0x0, 0x5a800, 0x1049b93c, 0x8000, 0x59a00, 0x1, 0x1047381c,
0x10473818)
["/xlv52/6.5.4f/work/gfx/lib/opengl/KONA/texture/kon_texture_mem.c":246,
0xdad9614]
1 getFreeBank(0x10463758, 0x5a800, 0x1049b93c, 0x8000, 0x0, 0x1, 0x1047381c,
0x0) ["/xlv52/6.5.4f/work/gfx/lib/opengl/KONA/texture/kon_texture_mem.c":664,
0xdada7e0]
2 __glKonTexAlloc(0x10463758, 0x1050a8d0, 0x0, 0x104c07d0, 0x59a00, 0x1,
0x1047381c, 0x10473818)
["/xlv52/6.5.4f/work/gfx/lib/opengl/KONA/texture/kon_texture_mem.c":1084,
0xdadaa34]
3 configTexture(0x0, 0x1050a8d0, 0x1049b93c, 0x8000, 0x0, 0x1, 0x1047381c,
0x10473818)
["/xlv52/6.5.4f/work/gfx/lib/opengl/KONA/texture/kon_texture_api.c":4239,
0xdad17ac]
4 checkTexImage(0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x104c07d0, 0x10473818)
["/xlv52/6.5.4f/work/gfx/lib/opengl/KONA/texture/kon_texture_api.c":5043,
0xdad3988]
5 __glkonim_TexImage(0xde1, 0x0, 0x0, 0x200, 0x200, 0x1, 0x0, 0x1907)
["/xlv52/6.5.4f/work/gfx/lib/opengl/KONA/texture/kon_texture_api.c":5269,
0xdad3d8c]
6 __glkonim_TexImage2D(0x0, 0x5a800, 0x1049b93c, 0x8000, 0x59a00, 0x1,
0x1047381c, 0x10473818)
["/xlv52/6.5.4f/work/gfx/lib/opengl/KONA/texture/kon_texture_api.c":5452,
0xdad4474]
I've seen close to the same traces on the Octane.
The problem looks pretty much like yours; the draw process takes 100% of CPU
and freezes up the pipeline. I think its poling the graphics h/w waiting for
something???
Indeed this happens when we oversubscribe TRAM. But since when is this a
problem besides the fact that performance might be affected.
We have since then tracked down the SGI bug entries that might relate to this.
You will find those in the attachments.
>
> Try pfumaketexlist followed by pfudownloadtexlist after you build your
> scene.
This cannot resolve the problem when dynamic texture management is needed.
>
> Also, use stats to count downloads.
>
> Reducing texture size as you have would prevent oversubscribing TRAM and
> reduce any paging overhead by a factor of 4, so it's unclear which is
> your problem.
Could it be something in IRIX ???
>
> Cheers,Angus.
>
> Hans-Peter.Hofer++at++se.admin.ch wrote:
> >
> > Hello Performer's
> >
> > My system:
> > Onyx2 InfiniteReality
> > 2 RM 7
> > 512 MB memory
> > IRIX 6.5.5 / Performer_eoe 2.2.6
> >
> > I have a 4 channel application.
> > Process model: APP_CULL_DRAW
> > The database uses 17 1024x1024 rgb-textures for the terrain and a lot of
> > smaller textures
> > for the objects. (64 MB texture memory is filled to 93%). No cliptextures.
> >
> > Now I have the following strange problem:
> >
> > When I drive through the database, sometimes the frame rate drops down
> > dramatically
> > (display stand still for 1-2 sec.) When I enable the statistic at the same
> > time, the display
> > output locks up (no frame update visible, sar -g shows buffer swap/sec: 0,
> > gr_osview shows 100% CPU
> > load for the draw, but nothing happens!).
> > The APP and the CULL process are running on (can terminate
> > the application via a normal keyboard input which is handled in the APP
main
> > loop).
> >
> > Reducing the viewport size or changing the LOD scale shows no significant
> > improvment.
> > But when I reduce the texture size from 104x1024 to 512x512 this strange
> > effects disappears .
> >
> > Does anybody know something about an effect like this?
> >
> > Thanks to all.
> >
> > Hans-Peter Hofer
> >
> > -----------------------------------------------------------------------
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>
> --
> For Performer+OpenGL tutorials http://www.dorbie.com/
>
> "In the middle of difficulty lies opportunity."
> --Albert Einstein
> -----------------------------------------------------------------------
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>-- End of excerpt from Angus Dorbie
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