disk thread problem when using RT-kernel

disk thread problem when using RT-kernel

[Victor henri]

Hello: 

I have a problem since almost one year now. I'm using linuxsampler, that allows that load very big sample files (one of my .gig file is 1.6 G for only one piano sound); this use disk streaming.

I always have such problem only when i use the RT kernel : 

0x7f6eef1ee860 Disk stream not available in time! 

After several message slike that, i get :

DiskThread: there was no free slot
Disk stream order failed!

Then the sounds clicks, then stops for 10 to 20 seconds, then i can play again, then it'll come again...

This arrives on both Gentoo and Ubuntu 10.10 64 bits; BUT there is one thing however : there is ONE kernel with wich it doesn't arrive : the 2.6.31.11-rt from Ubuntu lucid (RT kernel was in the repositories in Ubuntu untill 10.04 Lucid, then now i have to either take it  from Abogani's ppa (for lucid or natty) or compile it myself with the rt-patch from kernel.org; i've tried all of that, and nothings works, except for the 2.6.31.11-rt from in the repositories of Ubuntu Lucid-updates)

Here are some technical details:
    - I have laptop Asus Core i7 for gamers (supposed to be very fast);to be noted : it also happens on another Asus Core I7, but NOT on an another Asus Core i3; 4Go RAM;
    - when i compile myself i choose : real-time preemption (of course) and Timer frequency 1000 Hz, either on Gentoo or on Ubuntu with kernel from kernel.org; nothing else is changed in Ubuntu.
    - i've tried with the no-op cfq scheduler also; i use ext3 on Gentoo and ext4 on Ubuntu;
    - have a nvidia garphic card, but no proprietary driver installed....

Could please someone help me? i LOVE RT-kernel and its capabilities....


i have posted that to several lists, including linuxsampler's without succes....

Victor


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Re: disk thread problem when using RT-kernel

[Daniel James]

Hi Victor,

> - when i compile myself i choose : real-time preemption (of course)
> and Timer frequency 1000 Hz, either on Gentoo or on Ubuntu with
> kernel from kernel.org; nothing else is changed in Ubuntu.

Do you use the rtirq script?

http://alsa.opensrc.org/Rtirq

Cheers!

Daniel

Re: disk thread problem when using RT-kernel

[Daniel James]

Hi Victor,

p.s. You don't say which version of linuxsampler you are using - this
could be relevant, as most distros do not ship up to date versions.

Cheers!

Daniel

Re: disk thread problem when using RT-kernel

[Luis Claudio R. Goncalves]

On Sat, Jan 29, 2011 at 10:41:47PM +0100, Victor henri wrote:
...
| Here are some technical details:
|     - I have laptop Asus Core i7 for gamers (supposed to be very fast);to
| be noted : it also happens on another Asus Core I7, but NOT on an another
| Asus Core i3; 4Go RAM;

Have you tried running hwlat_detector? You (hopefully) can find it in your
kernel sources and notes on how to use it at Documentation/hwlat_detector.txt.
In short, you could be seeing long latencies spikes created by SMIs. That kernel
module, hwlat_detector, may help you identifying them.

The hint about setting the priority of the IRQ threads is also a good one.
You should also look at the logs of the USB/firewire/whatever you are using
to commounicate with your keyboard... you may be suffering buffer underruns
due to file size or something similar to it.

Luis
-- 
[ Luis Claudio R. Goncalves                    Bass - Gospel - RT ]
[ Fingerprint: 4FDD B8C4 3C59 34BD 8BE9  2696 7203 D980 A448 C8F8 ]

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RE: disk thread problem when using RT-kernel

[Victor henri]

Hello Daniel and Luis

 -  Yes i'm using the rtirq script;

 - I'm using the latest version of linuxsampler 1.0.0 (in Gentoo : from 
pro-audio overlay; in Ubuntu : not in the repositories so I compile it 
myself, after taking it on the linuxsampler website); same for libgig 
(dependency of linuxsampler);

 - I'll have a look at hwlat_detector; it seems not to be in the repositories in Ubuntu; i'll be searching;

 - regarding the logs  of the USB, how can I do it please? I'm using an 
external USB sound card (a M-Audio Fast Track Pro); the keybord is 
connected to the card via midi.

Thank you all

Victor

> Date: Mon, 31 Jan 2011 09:23:46 -0200
> From: lclaudio@uudg.org
> To: linux-rt-users@vger.kernel.org; nadaeck@hotmail.com
> Subject: Re: disk thread problem when using RT-kernel
> 
> On Sat, Jan 29, 2011 at 10:41:47PM +0100, Victor henri wrote:
> ...
> | Here are some technical details:
> |     - I have laptop Asus Core i7 for gamers (supposed to be very fast);to
> | be noted : it also happens on another Asus Core I7, but NOT on an another
> | Asus Core i3; 4Go RAM;
> 
> Have you tried running hwlat_detector? You (hopefully) can find it in your
> kernel sources and notes on how to use it at Documentation/hwlat_detector.txt.
> In short, you could be seeing long latencies spikes created by SMIs. That kernel
> module, hwlat_detector, may help you identifying them.
> 
> The hint about setting the priority of the IRQ threads is also a good one.
> You should also look at the logs of the USB/firewire/whatever you are using
> to commounicate with your keyboard... you may be suffering buffer underruns
> due to file size or something similar to it.
> 
> Luis
> -- 
> [ Luis Claudio R. Goncalves                    Bass - Gospel - RT ]
> [ Fingerprint: 4FDD B8C4 3C59 34BD 8BE9  2696 7203 D980 A448 C8F8 ]
> 
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> To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in
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Re: disk thread problem when using RT-kernel

[Luis Claudio R. Goncalves]

On Mon, Jan 31, 2011 at 03:16:37PM +0100, Victor henri wrote:
| 
| Hello Daniel and Luis
| 
|  -  Yes i'm using the rtirq script;
| 
|  - I'm using the latest version of linuxsampler 1.0.0 (in Gentoo : from 
| pro-audio overlay; in Ubuntu : not in the repositories so I compile it 
| myself, after taking it on the linuxsampler website); same for libgig 
| (dependency of linuxsampler);

Have you tried running linuxsample at a higher priority? I would try
running it as sched_fifo, priority 60 or 70. You can use 'chrt' to achieve
that.

|  - I'll have a look at hwlat_detector; it seems not to be in the
| repositories in Ubuntu; i'll be searching;

hwlat_detector is a kernel module. You just have to load the module and
tweak the values (though IIRC the defaults are sane) and let it run for a
while (at least 2h).

|  - regarding the logs  of the USB, how can I do it please? I'm using an 
| external USB sound card (a M-Audio Fast Track Pro); the keybord is 
| connected to the card via midi.

Have a look at /var/log/messages and dmesg and see if anything suspect
catches your eyes :)

Regards,
Luis
-- 
[ Luis Claudio R. Goncalves                    Bass - Gospel - RT ]
[ Fingerprint: 4FDD B8C4 3C59 34BD 8BE9  2696 7203 D980 A448 C8F8 ]

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RE: disk thread problem when using RT-kernel

[Victor henri]

Hello

I'm back after some testing.... and it is a complete mess; actually there is more than that just problems with linuxsampler.... with every RT kernel greater than 2.6.31.12 (i started seeing it on gentoo), i have total system freeze... after a few minutes.... to the point that i have to force shut down the system without proper shutdown (i hate doing that); i have installed "das-watchdog" and see the pop-up window saying that das watchdog has disabled real-time for 8 seconds... and this pop-up appears every 8 sec... (forever)... everything happen before i have time to play a single note....
This old problem is coming again... and i've open a new subject  to solve this first

Vic

> Date: Mon, 31 Jan 2011 13:17:49 -0200
> From: lclaudio@uudg.org
> To: nadaeck@hotmail.com
> CC: linux-rt-users@vger.kernel.org
> Subject: Re: disk thread problem when using RT-kernel
>
> On Mon, Jan 31, 2011 at 03:16:37PM +0100, Victor henri wrote:
> |
> | Hello Daniel and Luis
> |
> |  -  Yes i'm using the rtirq script;
> |
> |  - I'm using the latest version of linuxsampler 1.0.0 (in Gentoo : from
> | pro-audio overlay; in Ubuntu : not in the repositories so I compile it
> | myself, after taking it on the linuxsampler website); same for libgig
> | (dependency of linuxsampler);
>
> Have you tried running linuxsample at a higher priority? I would try
> running it as sched_fifo, priority 60 or 70. You can use 'chrt' to achieve
> that.
>
> |  - I'll have a look at hwlat_detector; it seems not to be in the
> | repositories in Ubuntu; i'll be searching;
>
> hwlat_detector is a kernel module. You just have to load the module and
> tweak the values (though IIRC the defaults are sane) and let it run for a
> while (at least 2h).
>
> |  - regarding the logs  of the USB, how can I do it please? I'm using an
> | external USB sound card (a M-Audio Fast Track Pro); the keybord is
> | connected to the card via midi.
>
> Have a look at /var/log/messages and dmesg and see if anything suspect
> catches your eyes :)
>
> Regards,
> Luis
> --
> [ Luis Claudio R. Goncalves                    Bass - Gospel - RT ]
> [ Fingerprint: 4FDD B8C4 3C59 34BD 8BE9  2696 7203 D980 A448 C8F8 ]
>
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Re: disk thread problem when using RT-kernel

[Nathan Grennan]

On 02/03/2011 12:50 PM, Victor henri wrote:
> Hello
>
> I'm back after some testing.... and it is a complete mess; actually there is more than that just problems with linuxsampler.... with every RT kernel greater than 2.6.31.12 (i started seeing it on gentoo), i have total system freeze... after a few minutes.... to the point that i have to force shut down the system without proper shutdown (i hate doing that); i have installed "das-watchdog" and see the pop-up window saying that das watchdog has disabled real-time for 8 seconds... and this pop-up appears every 8 sec... (forever)... everything happen before i have time to play a single note....
> This old problem is coming again... and i've open a new subject  to solve this first
   It sounds like you are running into the same problem I did a while 
back. I never got to the bottom of it. I am waiting for the 2.6.37-rt 
kernel. See my thread below.

http://www.spinics.net/lists/linux-rt-users/msg06248.html

RE: disk thread problem when using RT kernel

[Victor henri]

Hello
 
So if  i understand well 'soft lock' is what i have described in my post, and what you were experiencing.
 
The only solution is to wait then?
 
Thank you for your answer
 
Victor
 

----------------------------------------
> Date: Thu, 3 Feb 2011 13:02:38 -0800
> From: linux-rt-users@cygnusx-1.org
> To: linux-rt-users@vger.kernel.org
> Subject: Re: disk thread problem when using RT-kernel
>
> On 02/03/2011 12:50 PM, Victor henri wrote:
> > Hello
> >
> > I'm back after some testing.... and it is a complete mess; actually there is more than that just problems with linuxsampler.... with every RT kernel greater than 2.6.31.12 (i started seeing it on gentoo), i have total system freeze... after a few minutes.... to the point that i have to force shut down the system without proper shutdown (i hate doing that); i have installed "das-watchdog" and see the pop-up window saying that das watchdog has disabled real-time for 8 seconds... and this pop-up appears every 8 sec... (forever)... everything happen before i have time to play a single note....
> > This old problem is coming again... and i've open a new subject to solve this first
> It sounds like you are running into the same problem I did a while
> back. I never got to the bottom of it. I am waiting for the 2.6.37-rt
> kernel. See my thread below.
>
> http://www.spinics.net/lists/linux-rt-users/msg06248.html
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> To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in
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