rt-kernel and instability?

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basscania
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rt-kernel and instability?

Postby basscania » Sat May 15, 2010 3:52 pm

Hi all,

I thought this should be in a separate thread.

I am experiencing a lot of instability right now - when booted into the rt-kernel the system tends to freeze now and then. Very often so if I use Firefox.

I've also noticed that the CPU load monitor on my desktop (conky something) is constantly over 50% directly after boot, even if I am not running any apps at all. Checked this with htop and gnome-system-monitor (which I just installed because I was wondering about the cpu load, I'm quite familiar with that app) and they both give much lower values, like 5-10% with peaks now and then.

When booting into the ordinary kernel, cpu load is about 5% or so at startup according to conky. I have not configured conky (very new to it) so it may just be a settings thing.

I have written in a thread about tmpfs, I found that my system was getting buggy/instable after doing something with tmpfs in /tmp. As I had not edited fstab it should have been solved after reboot, but I am wondering? The thread is here: http://linuxmusicians.com/viewtopic.php?f=27&t=723

Maybe I'll have to reinstall once again? I'd prefer not to though...

I'm running CrunchBang 9.04.01 on an old desktop that was a great audio studio production machine when we bought it late in 2003... Of course, old stuff, RAM has been upgraded (not ddr3 or even ddr2 but ancient ddr...) from 1 GB to 3 GB. Sufficient fans I think and also a cooler from the manufacturer of the RAM we bought (OCZ). The motherboard MSI 865PE Neo2 is dual core, I'm quite a noob but I think it's quite ok?

So - can this be the rt-kernel (downloaded via Synaptic, I think it was linux-rt or something?) giving problems, or can it be something else that is wrong?

Suggestions for checks? Or maybe I'll have to reinstall again? :cry:

Thanks a lot in advance,
Cissi

djohnston
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Re: rt-kernel and instability?

Postby djohnston » Sat May 15, 2010 10:33 pm

I am a total newbie to home recording, but an old hand at Linux. I have done no tweaks yet on my system, so what I am showing here is the default fstab setup for the distro I use. tmpfs is mounted this way:

tmpfs /dev/shm tmpfs defaults 0 0

In the thread you pointed to, raboof said:

I wonder if this is still good advice.

The main reason for suggesting this was because jack used to put intermediate stuff in /tmp/jack . Nowadays, jack uses /dev/shm explicitly.

However, other applications might still be using /tmp, and it seems like a good idea to use tmpfs for that - after all, that's what it's for :).

What do you think? Should we still recommend mounting a tmpfs on /tmp? I tend to think so.


I don't know the answer. But, the current default for tmpfs for the distro I use is the one I listed above.

basscania
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Re: rt-kernel and instability?

Postby basscania » Sun May 16, 2010 3:40 pm

Hi djohnston,

Don't take this wrong please :? - but have you read my posts in the thread?

It might be just my computer, hardware issues or something else, but I am having big problems. It might be that 99% of all computers can "handle" that advice, but in my case something is seriously wrong...

And even if almost all computers (might be mine that is the exception to the rule) work fine with the advice, it can be that someone else might get the same problems I have? Even if rare, it can happen, and I would be happy if I can help anyone by pointing this out...

Right now, I am sadly convinced that a reinstall is needed. In our case, that is kind of a disaster. Hubby is extremely stressed up and really needs to get started with recording and stuff.

Before starting over with a new install, I'll go through the kernel log for the rt-kernel. It might be helpful to me, but more importantly it might give clues that might help someone else later?

As you know a lot about Linux, I am a complete noob myself with extremely limited background knowledge about computers in general, I would be very very happy if you would like to go through my posts in the thread I'm referring to. If possible, I would also be very very happy for input about the rt-kernel log that I will post here. It's extremely long of course, I'll try to cut out the things that I think might be important.

Suggestions about alternatives to the rt-kernel I'm using now (I'll post the exact version later) would be very good too, Zen:Core has given me some advice which I'm very happy about.

Now I'll go through the log :? - hope I can get something out of that... :roll: :wink:

Best wishes,
Cissi

djohnston wrote:I am a total newbie to home recording, but an old hand at Linux. I have done no tweaks yet on my system, so what I am showing here is the default fstab setup for the distro I use. tmpfs is mounted this way:

tmpfs /dev/shm tmpfs defaults 0 0

In the thread you pointed to, raboof said:

I wonder if this is still good advice.

The main reason for suggesting this was because jack used to put intermediate stuff in /tmp/jack . Nowadays, jack uses /dev/shm explicitly.

However, other applications might still be using /tmp, and it seems like a good idea to use tmpfs for that - after all, that's what it's for :).

What do you think? Should we still recommend mounting a tmpfs on /tmp? I tend to think so.


I don't know the answer. But, the current default for tmpfs for the distro I use is the one I listed above.

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raboof
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Re: rt-kernel and instability?

Postby raboof » Sun May 16, 2010 4:21 pm

basscania wrote:Right now, I am sadly convinced that a reinstall is needed.


If you're having trouble with the rt-kernel, why not just go with the default non-rt kernel for now?

basscania wrote:In our case, that is kind of a disaster. Hubby is extremely stressed up and really needs to get started with recording and stuff.


Relax, stress is never good! Perhaps your husband can help getting the system set up the way you both want it? Figuring out what's really needed, which tools will do the job? Even if the job doesn't get done any faster that way, it may relief some of the stress...

basscania
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Re: rt-kernel and instability?

Postby basscania » Sun May 16, 2010 4:40 pm

Raboof, first of all a big hug and a big thank you for your post! :D

raboof wrote:
basscania wrote:Right now, I am sadly convinced that a reinstall is needed.


If you're having trouble with the rt-kernel, why not just go with the default non-rt kernel for now?

basscania wrote:In our case, that is kind of a disaster. Hubby is extremely stressed up and really needs to get started with recording and stuff.


Relax, stress is never good! Perhaps your husband can help getting the system set up the way you both want it? Figuring out what's really needed, which tools will do the job? Even if the job doesn't get done any faster that way, it may relief some of the stress...


Well, hubby does not have any Linux knowledge or experience at all, so it's sort of all up to me... And he's asking me all the time when he can get started with recording. He wants to know when, like tomorrow? I have no clues. I am just hoping that I'll get this fixed ASAP and I feel that it's been on my mind 24/7 for weeks now.

I have no idea where to turn, I'd be so very happy to pay for assistance (even though I'm not well off so to say) but who can help? I don't know anyone besides the forums I use... We live in southern Sweden, have a good friend that's good with Linux but he's only into Ubuntu Studio I think and that is not working here. That was our first try.

I'd be happy to supply any information I can about the computer we have, it's old but on the other hand it was specially built to be a studio machine? Should be decent hardware?

Right now I'm looking through the rt-kernel log, not really sure what I'm looking for, anything that has the words "warning" or "error" is interesting of course... Found this for example, just a short part of the log:

Code: Select all

May 15 16:54:49 hogan-desktop kernel: [  905.692909] mtrr: no MTRR for f0000000,4000000 found
May 15 16:55:49 hogan-desktop kernel: Inspecting /boot/System.map-2.6.28-3-rt
May 15 16:55:49 hogan-desktop kernel: Cannot find map file.
May 15 16:55:50 hogan-desktop kernel: Loaded 54496 symbols from 54 modules.
May 15 16:55:50 hogan-desktop kernel: [    0.000000] BIOS EBDA/lowmem at: 0009fc00/0009fc00
May 15 16:55:50 hogan-desktop kernel: [    0.000000] Initializing cgroup subsys cpuset
May 15 16:55:50 hogan-desktop kernel: [    0.000000] Initializing cgroup subsys cpu
May 15 16:55:50 hogan-desktop kernel: [    0.000000] Linux version 2.6.28-3-rt (buildd@vernadsky) (gcc version 4.3.3 (Ubuntu 4.3.3-5ubuntu4) ) #12-Ubuntu SMP PREEMPT RT Fri Apr 17 10:09:11 UTC 2009 (Ubuntu 2.6.28-3.12-rt)

and further down:

Code: Select all

May 15 16:55:50 hogan-desktop kernel: [    0.000000] AMI BIOS detected: BIOS may corrupt low RAM, working it around.
May 15 16:55:50 hogan-desktop kernel: [    0.000000] last_pfn = 0xbfff0 max_arch_pfn = 0x100000
May 15 16:55:50 hogan-desktop kernel: [    0.000000] Scanning 0 areas for low memory corruption

and further down:

Code: Select all

May 15 16:55:50 hogan-desktop kernel: [    0.000000] (9 early reservations) ==> bootmem [0000000000 - 00373fe000]
May 15 16:55:50 hogan-desktop kernel: [    0.000000]   #0 [0000000000 - 0000001000]   BIOS data page ==> [0000000000 - 0000001000]
May 15 16:55:50 hogan-desktop kernel: [    0.000000]   #1 [0000001000 - 0000002000]    EX TRAMPOLINE ==> [0000001000 - 0000002000]

and further down:

Code: Select all

May 15 16:55:50 hogan-desktop kernel: [    0.000000] ACPI: IRQ0 used by override.
May 15 16:55:50 hogan-desktop kernel: [    0.000000] ACPI: IRQ2 used by override.
May 15 16:55:50 hogan-desktop kernel: [    0.000000] ACPI: IRQ9 used by override.
May 15 16:55:50 hogan-desktop kernel: [    0.000000] Enabling APIC mode:  Flat.  Using 1 I/O APICs
May 15 16:55:50 hogan-desktop kernel: [    0.000000] Using ACPI (MADT) for SMP configuration information
May 15 16:55:50 hogan-desktop kernel: [    0.000000] SMP: Allowing 2 CPUs, 0 hotplug CPUs


there is also a line about SELinux disabled at boot?

I really don't know what to look for...

Thanks again for your post!

Best wishes,
Cissi

thorgal
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Re: rt-kernel and instability?

Postby thorgal » Sun May 16, 2010 4:52 pm

looks like you have the "cgroup" stuff enabled. Never ever used that myself. I compile my own kernel and disable that stuff as it used to have some interfence with RT operations. Someone wrote how to use the cgroup stuff in conjunction with RT scheduling but honestly, I don't remember where that is and if that's relevant.

The cgroup feature is a way to define groups for users and processes that can be configured for special processing execution.

It could also well be that I am talking rubbish :)

brummer

Re: rt-kernel and instability?

Postby brummer » Sun May 16, 2010 5:14 pm

When I get it right, CrunchBang 10 is debian Squeeze based, where CrunchBang Linux 9.04.01 is based on Ubuntu. That means to me, the CrunchBang developers found the plain debian base suit more there need's.
Witch version of CrunchBang have you installed, and witch is your kernel version ?

If you use CrunchBang 10, you could give the AV Linux kernel a try :
http://www.bandshed.net/Packages.html

greats brummer

basscania
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Re: rt-kernel and instability?

Postby basscania » Sun May 16, 2010 5:29 pm

Hi Thorgal,

Just sent you a pm, don't know why these tend to get stuck in my outbox for hours though...

thorgal wrote:looks like you have the "cgroup" stuff enabled. Never ever used that myself. I compile my own kernel and disable that stuff as it used to have some interfence with RT operations.

...

It could also well be that I am talking rubbish :)


I'll google the cgroup thing, thanks a lot for the advice! :)

You talking rubbish? No way! :D :wink:

Best wishes,
Cissi

basscania
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Posts: 38
Joined: Fri Apr 16, 2010 10:46 pm

Re: rt-kernel and instability?

Postby basscania » Sun May 16, 2010 5:57 pm

Hi dear Brummer,

Thanks for the input! :)

brummer wrote:When I get it right, CrunchBang 10 is debian Squeeze based, where CrunchBang Linux 9.04.01 is based on Ubuntu. That means to me, the CrunchBang developers found the plain debian base suit more there need's.
Witch version of CrunchBang have you installed, and witch is your kernel version ?

If you use CrunchBang 10, you could give the AV Linux kernel a try :
http://www.bandshed.net/Packages.html

greats brummer


I have CB 9.04.01 (Ubuntu based), didn't dare to try the Statler thing as I'm worried about the latest Cups? It's a bug in it so we can not use our Canon printer that is connected via usb... Have to stay away from the latest Cups...

The latest AV Linux kernel would not work with CB 9.04.01 I guess? Ubuntu versus debian thing I suppose?

As for AV Linux, wanted to try that, but it only comes as DVD. I can burn a DVD on my Xubuntu desktop without problems but for some odd reason I'm having problems on this desktop to boot from DVD... (Tried both the Nec DVD reader and the ASUS CD-burner, does not work?)

Now I have CB 9.04.01 full but I've had 9.04.01 lite aswell.
kernel: 2.6.28-18-generic (#60-Ubuntu SMP Fri Mar 12 04:40:52 UTC 2010) (the one I'm booted into right now, info from sysinfo) (also says no gcc detected, xorg version unknown?)
kernel: linux-rt-2.6.28/arch/x86/kernel (from the rt kernel log)

CPU according to sysinfo: Intel(R) Pentium(R) 4 CPU 2.80GHz, 2800.163 MHz, L2 cache 512 kB, flags fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe pebs bts cid xtpr, two cpus.

Memory 3024 MB

Graphic card Nvidia GeForce4 MX 440 AGP 8x (we've stayed away from the proprietary drivers)

Sound card: M-Audio Audiophile 2496, ICE1712 (Envy24) PCI multi-channel (plus a sound card on the motherboard that is disabled in bios)

Motherboard: MSI 865PE Neo2

HDDs: internal Samsung SP1634N external Samsung SP2514N plus one HDD plugged into the router.

I'd be happy to give any other info, just let me know!

About reinstall - I think it might be good to "clean out" any errors I might have done. Wouldn't take that much time?

Best wishes,
Cissi

djohnston
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Re: rt-kernel and instability?

Postby djohnston » Tue May 18, 2010 3:33 am

basscania wrote:Hi djohnston,

Don't take this wrong please :? - but have you read my posts in the thread?


No, honestly, I had not. Your post in this thread, which began this thread, was the only one of yours I had read. It is also my first post on this forum.

basscania wrote: would be very very happy if you would like to go through my posts in the thread I'm referring to.


Well, I will see if I can locate the one you mean, since you didn't show a link to it.

I guess I misinterpreted what you are asking for. I never intended to get you so upset.

werock
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Re: rt-kernel and instability?

Postby werock » Tue May 18, 2010 8:28 pm

basscania wrote:
I have no idea where to turn, I'd be so very happy to pay for assistance (even though I'm not well off so to say) but who can help? I don't know anyone besides the forums I use... We live in southern Sweden, have a good friend that's good with Linux but he's only into Ubuntu Studio I think and that is not working here. That was our first try.

I'd be happy to supply any information I can about the computer we have, it's old but on the other hand it was specially built to be a studio machine? Should be decent hardware?

Right now I'm looking through the rt-kernel log, not really sure what I'm looking for, anything that has the words "warning" or "error" is interesting of course... Found this for example, just a short part of the log:

Code: Select all

May 15 16:54:49 hogan-desktop kernel: [  905.692909] mtrr: no MTRR for f0000000,4000000 found
May 15 16:55:49 hogan-desktop kernel: Inspecting /boot/System.map-2.6.28-3-rt
May 15 16:55:49 hogan-desktop kernel: Cannot find map file.
May 15 16:55:50 hogan-desktop kernel: Loaded 54496 symbols from 54 modules.
May 15 16:55:50 hogan-desktop kernel: [    0.000000] BIOS EBDA/lowmem at: 0009fc00/0009fc00
May 15 16:55:50 hogan-desktop kernel: [    0.000000] Initializing cgroup subsys cpuset
May 15 16:55:50 hogan-desktop kernel: [    0.000000] Initializing cgroup subsys cpu
May 15 16:55:50 hogan-desktop kernel: [    0.000000] Linux version 2.6.28-3-rt (buildd@vernadsky) (gcc version 4.3.3 (Ubuntu 4.3.3-5ubuntu4) ) #12-Ubuntu SMP PREEMPT RT Fri Apr 17 10:09:11 UTC 2009 (Ubuntu 2.6.28-3.12-rt)

and further down:

Code: Select all

May 15 16:55:50 hogan-desktop kernel: [    0.000000] AMI BIOS detected: BIOS may corrupt low RAM, working it around.
May 15 16:55:50 hogan-desktop kernel: [    0.000000] last_pfn = 0xbfff0 max_arch_pfn = 0x100000
May 15 16:55:50 hogan-desktop kernel: [    0.000000] Scanning 0 areas for low memory corruption

and further down:

Code: Select all

May 15 16:55:50 hogan-desktop kernel: [    0.000000] (9 early reservations) ==> bootmem [0000000000 - 00373fe000]
May 15 16:55:50 hogan-desktop kernel: [    0.000000]   #0 [0000000000 - 0000001000]   BIOS data page ==> [0000000000 - 0000001000]
May 15 16:55:50 hogan-desktop kernel: [    0.000000]   #1 [0000001000 - 0000002000]    EX TRAMPOLINE ==> [0000001000 - 0000002000]

and further down:

Code: Select all

May 15 16:55:50 hogan-desktop kernel: [    0.000000] ACPI: IRQ0 used by override.
May 15 16:55:50 hogan-desktop kernel: [    0.000000] ACPI: IRQ2 used by override.
May 15 16:55:50 hogan-desktop kernel: [    0.000000] ACPI: IRQ9 used by override.
May 15 16:55:50 hogan-desktop kernel: [    0.000000] Enabling APIC mode:  Flat.  Using 1 I/O APICs
May 15 16:55:50 hogan-desktop kernel: [    0.000000] Using ACPI (MADT) for SMP configuration information
May 15 16:55:50 hogan-desktop kernel: [    0.000000] SMP: Allowing 2 CPUs, 0 hotplug CPUs


there is also a line about SELinux disabled at boot?

I really don't know what to look for...

Thanks again for your post!

Best wishes,
Cissi


The only bit of advice I can offer you is to try an Audio specific distribution. Studio 64 has always seemed to have worked well for a number of people here. I have just installed AV Linux which works really well. Before that I had Ubuntu Studio 8.04 which was OK, but I did suffer from a number of audio glitches (pops & clicks) which I don't get with AV Linux.

So grab yourself the live DVD of AV Linux and try it out without installing it. You should get a good idea of how well it works on your system. The advantage of AV Linux or Studio 64 is that you shouldn't have to do any tinkering to get the system to work well.

Of course it does mean a re-install in the end, but as long as you have all your data backed up it's not a problem.

Hope this helps,
Andy.


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