snd-hdsp oddities

snd-hdsp oddities

[ico-rDkNP/OoUoU]

Hi all,

I am using the latest 2.6.7 kernel (tried also 2.6.5) but with hdsp I cannot select anything lower than 1024x2 buffer settings in jackd without having massive xruns.

Asoundrc is fine, modprobe.conf is fine too.

The hdsp runs fine with the aforementioned settings but anything lower simply is horrible.

The kernel is patched with all kinds of mm patches but I am not currently using -r option nor the realtime module (a bit scared of freezing my machine :-). Is this the best one can do in user-space?

Any help is greatly appreciated!

Best wishes,

Ico

Re: snd-hdsp oddities

[Paul Davis]

>I am using the latest 2.6.7 kernel (tried also 2.6.5) but with hdsp I cannot s
>elect anything lower than 1024x2 buffer settings in jackd without having massi
>ve xruns.

Give up on 2.6 for now. If you can't give up on it, then at least run
all (audio) apps with the environment variable LD_ASSUME_KERNEL set to
2.4.19. 

When the dust settles from the kernel and NPTL, 2.6 will be more
viable. Right now, even though it works for some people, its not a
generally viable platform for realtime audio.

--p

Re: Re: [linux-audio-dev] snd-hdsp oddities

[Russell King]

On Thu, Jul 01, 2004 at 10:16:39PM -0400, Paul Davis wrote:
> >I am using the latest 2.6.7 kernel (tried also 2.6.5) but with hdsp I cannot s
> >elect anything lower than 1024x2 buffer settings in jackd without having massi
> >ve xruns.
> 
> Give up on 2.6 for now. If you can't give up on it, then at least run
> all (audio) apps with the environment variable LD_ASSUME_KERNEL set to
> 2.4.19. 

That is a bad attitude IMHO - if everyone follows that example, it
means that 2.6 will _never_ progress.  We, as kernel, developers rely
completely on users running the thing to find any problems, so these
types of reports are invaluable.

Ico - isn't this the same device which we recently had problems with
on PCMCIA?

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 PCMCIA      - http://pcmcia.arm.linux.org.uk/
                 2.6 Serial core


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Re: [Alsa-devel] Re: snd-hdsp oddities

[Takashi Iwai]

At Thu, 01 Jul 2004 22:16:39 -0400,
Paul Davis wrote:
> 
> >I am using the latest 2.6.7 kernel (tried also 2.6.5) but with hdsp I cannot s
> >elect anything lower than 1024x2 buffer settings in jackd without having massi
> >ve xruns.
> 
> Give up on 2.6 for now. If you can't give up on it, then at least run
> all (audio) apps with the environment variable LD_ASSUME_KERNEL set to
> 2.4.19. 
> 
> When the dust settles from the kernel and NPTL, 2.6 will be more
> viable. Right now, even though it works for some people, its not a
> generally viable platform for realtime audio.

Hmm, except for some sched policy setting problems on NPTL, I don't
see bigger problem than 2.4+preempt kernel.  For some people,
2.4+preempt might work _casually_ better than 2.6, but it can happen
vice versa.

Shouting "DON'T USE 2.6" isn't a good solution.  Though, we need to
inform to "set LD_ASSUME_KERNEL as a workaround"...


Takashi

Re: [Alsa-devel] Re: snd-hdsp oddities

[Florian Schmidt]

On Fri, 02 Jul 2004 11:40:28 +0200
Takashi Iwai <tiwai-l3A5Bk7waGM@public.gmane.org> wrote:

> > When the dust settles from the kernel and NPTL, 2.6 will be more
> > viable. Right now, even though it works for some people, its not a
> > generally viable platform for realtime audio.
> 
> Hmm, except for some sched policy setting problems on NPTL, I don't
> see bigger problem than 2.4+preempt kernel.  For some people,
> 2.4+preempt might work _casually_ better than 2.6, but it can happen
> vice versa.
> 
> Shouting "DON'T USE 2.6" isn't a good solution.  Though, we need to
> inform to "set LD_ASSUME_KERNEL as a workaround"...

Yes, but i wonder: many other people use NPTL for many kinds of applications w/o problems.. The jack source code is too complex for me to really find my way through it, but maybe someone might consider summing up how jack handles threads and provide pointers into the source at the relevant spots.. Maybe NPTL isn't at fault, but jack..

Also, i think it would be very useful to have  simplified test case which shows the "erraneous" behaviour of jack/NPTL.. 

flo


-- 
Palimm Palimm!
http://affenbande.org/~tapas/wiki

Re: [Alsa-devel] Re: snd-hdsp oddities

[Takashi Iwai]

At Fri, 2 Jul 2004 13:26:44 +0200,
Florian Schmidt wrote:
> 
> On Fri, 02 Jul 2004 11:40:28 +0200
> Takashi Iwai <tiwai-l3A5Bk7waGM@public.gmane.org> wrote:
> 
> > > When the dust settles from the kernel and NPTL, 2.6 will be more
> > > viable. Right now, even though it works for some people, its not a
> > > generally viable platform for realtime audio.
> > 
> > Hmm, except for some sched policy setting problems on NPTL, I don't
> > see bigger problem than 2.4+preempt kernel.  For some people,
> > 2.4+preempt might work _casually_ better than 2.6, but it can happen
> > vice versa.
> > 
> > Shouting "DON'T USE 2.6" isn't a good solution.  Though, we need to
> > inform to "set LD_ASSUME_KERNEL as a workaround"...
> 
> Yes, but i wonder: many other people use NPTL for many kinds of
> applications w/o problems.. The jack source code is too complex for me
> to really find my way through it, but maybe someone might consider
> summing up how jack handles threads and provide pointers into the
> source at the relevant spots.. Maybe NPTL isn't at fault, but jack.. 

Well, it's hard to determine at this point.
It could be a bug of pthread_setschedparm() on NPTL.

> Also, i think it would be very useful to have  simplified test case
> which shows the "erraneous" behaviour of jack/NPTL..  

Yes, definitely.


Takashi

Re: snd-hdsp oddities

[Russell King]

[-- Attachment #1: Type: text/plain, Size: 444 bytes --]

Could you please refrain from cross posting between here and the
linux-audio-dev mailing list?

For those of us who aren't on the linux-audio-dev list, we regularly
get our replies rejected for no reason by the moderator there.  (See
attached message.)

Thanks.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 PCMCIA      - http://pcmcia.arm.linux.org.uk/
                 2.6 Serial core

[-- Attachment #2: Type: message/rfc822, Size: 1844 bytes --]

From: linux-audio-dev-bounces@music.columbia.edu
To: rmk+alsa@arm.linux.org.uk
Subject: Request to mailing list linux-audio-dev rejected
Date: Mon, 05 Jul 2004 07:55:45 -0400
Message-ID: <mailman.5.1089028545.20569.linux-audio-dev@music.columbia.edu>

Your request to the linux-audio-dev mailing list

    Posting of your message titled "Re: [Alsa-devel] Re:
[linux-audio-dev] snd-hdsp oddities"

has been rejected by the list moderator.  The moderator gave the
following reason for rejecting your request:

"No reason given"

Any questions or comments should be directed to the list administrator
at:

    linux-audio-dev-owner@music.columbia.edu

RE: snd-hdsp oddities

[Ivica Ico Bukvic]

Your posts are not being rejected for "no reason," but because you need to
subscribe to the list to be able to post (just like the alsa-dev list). That
being said, I am cross-posting exactly for this reason, as I want to target
both the subscribers of lad and alsa-dev as this pertains to both groups
(especially because some of the members, such as yourself, are subscribed to
just one of these).

What I can do, however, is try to use bcc fields so that way you should
never see the other lists this has been cross-posted to and therefore your
e-mailing client should never reply to them either. This, however will still
require you to make sure that a copy of your e-mail reaches the alsa-dev
list by adding it to the cc: field and therefore will ask for the same
amount of attention as just removing lad list from the list of recipients...

Best wishes,

Ivica Ico Bukvic, composer & multimedia sculptor
http://meowing.ccm.uc.edu/~ico/
 

> -----Original Message-----
> From: Russell King [mailto:rmk@arm.linux.org.uk] On Behalf Of Russell King
> Sent: Monday, July 05, 2004 8:00 AM
> To: ico@fuse.net
> Cc: alsa-devel@lists.sourceforge.net
> Subject: Re: [Alsa-devel] snd-hdsp oddities
> 
> Could you please refrain from cross posting between here and the
> linux-audio-dev mailing list?
> 
> For those of us who aren't on the linux-audio-dev list, we regularly
> get our replies rejected for no reason by the moderator there.  (See
> attached message.)
> 
> Thanks.
> 
> --
> Russell King
>  Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
>  maintainer of:  2.6 PCMCIA      - http://pcmcia.arm.linux.org.uk/
>                  2.6 Serial core




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Re: snd-hdsp oddities

[ico-rDkNP/OoUoU]

> Shouting "DON'T USE 2.6" isn't a good solution.  Though, we need to
> inform to "set LD_ASSUME_KERNEL as a workaround"...

Pardon my ignorance but how does one do this? As a part of the config before compiling kernel or?

Also, any ideas on the odd behavior of the hdspmixer? (see my other post)

Ico

Re: Re: [linux-audio-dev] snd-hdsp oddities

[Takashi Iwai]

At Fri, 2 Jul 2004 12:56:06 +0000,
<ico@fuse.net> wrote:
> 
> > Shouting "DON'T USE 2.6" isn't a good solution.  Though, we need to
> > inform to "set LD_ASSUME_KERNEL as a workaround"...
> 
> Pardon my ignorance but how does one do this? As a part of the
> config before compiling kernel or? 

No, just set the environment variable like
	export LD_ASSUME_KERNEL=2.4.19
(better globally) and start jack.  That's all.

In this way, glibc chooses LinuxThreads instead of NPTL.

> Also, any ideas on the odd behavior of the hdspmixer? (see my other post)

Not checked yet...  Did hdspmixer work on any versions correctly on
your system?


Takashi


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Re: [Alsa-devel] Re: snd-hdsp oddities

[Florian Schmidt]

On Fri, 02 Jul 2004 15:15:46 +0200
Takashi Iwai <tiwai-l3A5Bk7waGM@public.gmane.org> wrote:

> At Fri, 2 Jul 2004 12:56:06 +0000,
> <ico-rDkNP/OoUoU@public.gmane.org> wrote:
> > 
> > > Shouting "DON'T USE 2.6" isn't a good solution.  Though, we need to
> > > inform to "set LD_ASSUME_KERNEL as a workaround"...
> > 
> > Pardon my ignorance but how does one do this? As a part of the
> > config before compiling kernel or? 
> 
> No, just set the environment variable like
> 	export LD_ASSUME_KERNEL=2.4.19
> (better globally) and start jack.  That's all.

yes, every jack client needs to be started with this env var set [additionally to the jack server], too.. otherwise it's not sufficient..

flo

P.S.: so add

export LD_ASSUME_KERNEL=2.4.19

to your ~/.bashrc

or even to your ~/.profile


-- 
Palimm Palimm!
http://affenbande.org/~tapas/wiki