Re: [gentoo-user] bad jack(?) performance

[Matt Garman]

On Thu, Oct 13, 2005 at 05:06:22AM -0700, Mark Knecht wrote:
> The first one is easy. Try some different Jack settings. Instead
> of 128/2 try 64/4, or 128/3, etc., and see if some other setting
> works.  You might get the same latency, or you might have to go a
> bit slower.  The only time I actually use low latency is when
> recording. It's never needed for playback only. Most of the time I
> run 512/2 just to ensure no xruns causing clicks in my work.

I haven't had a chance to try that yet, but still I wonder: why
should I have to tweak jack's settings, if 128/2 worked fine for
root?

> On my 32-bit machines I've always been able to run Jack the
> standard Gentoo-sources  kernel and get good realtime results. I
> have had to be careful about what options I choose, and on a
> couple of machines different kernel options have caused xruns
> (such as networking) but I've always managed to get it to work and
> work well. Sometimes it has taken some time, but it has worked.
> Maybe we need to look at how you are configuring the kernel.
> Possibly send your config file off list or I'll send you one of
> mine.

Ehhh, that scares me a bit (the thought that random kernel options
can affect Jack performance)!  My kernel config is fairly custom, as
I went through each option one-by-one and (at least tried to) set it
most appropriately for my hardware.

But I'm still hung up on the fact that things work as expected as
root, but automatically get "nice'ed" as a regular user.

> and I would have to manage updates on our own. That said, this is
> the way most people interested in good realtime performance have
> gone.  Maybe I've just been excessively lucky up until now.

And at this point I'm not too interested in that good of realtime
performance, though I will in the future (see below).

> It's probably worth it to review how you've set up realtime-lsm
> one more time, just in case, and possibly to look at your hardware
> setup a bit.

I agree, as I alluded to above, I'm thinking it might be a
permissions/setup issue.

> lspci

0000:00:00.0 Host bridge: nVidia Corporation nForce2 AGP (different version?) (rev c1)
0000:00:00.1 RAM memory: nVidia Corporation nForce2 Memory Controller 1 (rev c1)
0000:00:00.2 RAM memory: nVidia Corporation nForce2 Memory Controller 4 (rev c1)
0000:00:00.3 RAM memory: nVidia Corporation nForce2 Memory Controller 3 (rev c1)
0000:00:00.4 RAM memory: nVidia Corporation nForce2 Memory Controller 2 (rev c1)
0000:00:00.5 RAM memory: nVidia Corporation nForce2 Memory Controller 5 (rev c1)
0000:00:01.0 ISA bridge: nVidia Corporation nForce2 ISA Bridge (rev a4)
0000:00:01.1 SMBus: nVidia Corporation nForce2 SMBus (MCP) (rev a2)
0000:00:02.0 USB Controller: nVidia Corporation nForce2 USB Controller (rev a4)
0000:00:02.1 USB Controller: nVidia Corporation nForce2 USB Controller (rev a4)
0000:00:02.2 USB Controller: nVidia Corporation nForce2 USB Controller (rev a4)
0000:00:05.0 Multimedia audio controller: nVidia Corporation nForce Audio Processing Unit (rev a2)
0000:00:06.0 Multimedia audio controller: nVidia Corporation nForce2 AC97 Audio Controler (MCP) (rev a1)
0000:00:08.0 PCI bridge: nVidia Corporation nForce2 External PCI Bridge (rev a3)
0000:00:09.0 IDE interface: nVidia Corporation nForce2 IDE (rev a2)
0000:00:0c.0 PCI bridge: nVidia Corporation nForce2 PCI Bridge (rev a3)
0000:00:1e.0 PCI bridge: nVidia Corporation nForce2 AGP (rev c1)
0000:01:0a.0 SCSI storage controller: LSI Logic / Symbios Logic 53c1010 Ultra3 SCSI Adapter (rev 01)
0000:01:0a.1 SCSI storage controller: LSI Logic / Symbios Logic 53c1010 Ultra3 SCSI Adapter (rev 01)
0000:02:01.0 Ethernet controller: 3Com Corporation 3C920B-EMB Integrated Fast Ethernet Controller [Tornado] (rev 40)
0000:03:00.0 VGA compatible controller: nVidia Corporation NV28 [GeForce4 Ti 4200 AGP 8x] (rev a1)

> lsmod

Module                  Size  Used by
realtime                7752  0 
parport_pc             31812  1 
lp                      8260  0 
parport                20992  2 parport_pc,lp
usblp                  11072  0 
uhci_hcd               29200  0 
ehci_hcd               27272  0 
ohci_hcd               16584  0 
nvidia_agp              5916  1 
snd_pcm_oss            48288  0 
snd_mixer_oss          17664  1 snd_pcm_oss
snd_intel8x0           28032  3 
snd_ac97_codec         72192  1 snd_intel8x0
snd_pcm                81352  5 snd_pcm_oss,snd_intel8x0,snd_ac97_codec
snd_timer              21700  1 snd_pcm
snd                    45156  10 snd_pcm_oss,snd_mixer_oss,snd_intel8x0,snd_ac97_codec,snd_pcm,snd_timer
soundcore               7776  1 snd
snd_page_alloc          7620  2 snd_intel8x0,snd_pcm
w83l785ts               5716  0 
asb100                 21908  0 
i2c_sensor              2944  2 w83l785ts,asb100
i2c_nforce2             5504  0 
i2c_isa                 1728  0 
i2c_dev                 8064  0 
i2c_core               18512  6 w83l785ts,asb100,i2c_sensor,i2c_nforce2,i2c_isa,i2c_dev
nvidia               3707080  12 
agpgart                28648  2 nvidia_agp,nvidia

> cat /proc/asound/cards

0 [nForce2        ]: NFORCE - NVidia nForce2
                     NVidia nForce2 with ALC650F at 0xe2083000, irq 21

> What audio stuff are you going to use this machine for, BTW?

Right now, I just want multiplexing of audio streams for listening
to music/watching movies/hearing sound effects---typical "desktop
stuff" where more than one audio stream would be nice.

I'm starting to think that maybe jack+realtime is way overkill for
what I need... Though, in the future, I intend to build an amatuer
recording studio in my home, and I'd like to use Linux and OSS apps
as my multi-tracking software and drum machine.  So I thought it
would be nice to learn jack now :)

Anyway, thank you very much for all you help!  It is very much
appreciated.

Matt

-- 
Matt Garman
email at: http://raw-sewage.net/index.php?file=email
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