Can I turn off logging "debug" level kernel messages?

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Level 1

5 points

Can I turn off logging "debug" level kernel messages?

I'm a musician running a laptop rig (OSX 10.9.5) and am experiencing a fairly rare (once in about 10-15 gigs) and random situation of my audio being interrupted for a few seconds (buzzes or cuts out completely). When I look in Console I see that at the exact time this happens, asl is flooded with over a thousand messages like this:

kernel[0] <Debug>: IOAudioStream[0xffffff802b934c00]::clipIfNecessary() - Error: attempting to clip to a position more than one buffer ahead of last clip position (147a,1fc)->(147d,27c).

I have little hope of finding the exact cause of this but from what I've read, I suspect that it's the flooding of the log causing the audio dropouts, not the error itself! At least it's a theory that I'd like to explore. After doing more research I was under the impression that going into Terminal, logged in as root, and entering syslog -c 0 -n would set a mask so that these debug-level messages would not be logged. I confirmed that the command took because I entered syslog -c 0, the result being Master filter mask: Emergency - Notice. After a gig the other night I went into Console and sure enough there was a flood of these errors still showing up (I didn't hear any audio hiccups, I guess there weren't quite enough for that). I immediately confirmed that the master filter mask was still set to Emergency - Notice. That's the mystery I'd like to solve! Obviously I'm doing something wrong, like misunderstanding what syslog does, or perhaps what I'm looking to do isn't possible. I would like to suppress the logging of these debug-level messages. I think I may also be able to accomplish this by editing /etc/asl.conf so I don't need to go into Terminal after each reboot. Any guidance with this would be appreciated, as well as insights as to why the masking doesn't seem to be working in the first place. Thanks!

MacBook Pro with Retina display, OS X Mavericks (10.9.5)

Posted on Apr 3, 2015 9:26 AM

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Answer 1

reezekeys Author

Level 1

5 points

Apr 3, 2015 9:42 AM in response to reezekeys

OK I'm really confused now. These lines are in my asl.conf file:

# save everything from emergency to notice

? [<= Level notice] store

Why am I seeing the "debug" level messages in my asl log files? Is this a bug? The modification date on asl.conf is December 21, 2014 – I thought I just set the mask the other day.

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Answer 2

Linc Davis

Level 10

209,541 points

Apr 3, 2015 8:34 PM in response to reezekeys

Your assumption is not correct. The log messages mean that something is wrong with the audio subsystem, probably because of audio plugins or some other third-party system modification that you installed.

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Answer 3

reezekeys Author

Level 1

5 points

Apr 4, 2015 8:43 AM in response to Linc Davis

Your answer is not helpful. My question was regarding logging of debug-level error messages.

It probably won't do much good to engage any further about the original problem I'm dealing with, but here is what an Apple engineer had to say about these clipIfNecessary() messages: "The log message about this is probably unnecessary and should probably be relegated to debug builds." Link:

https://groups.google.com/forum/#!topic/coreaudio-api/GXXUWIYAb_k

It's probably true that my combination of software might be the cause, but if these clipIfNecessary() messages can occur without audio issues (and they certainly have), I am simply wanting to try disabling the logging of those messages to test my theory that it's the flooding of messages causing the audio dropouts. If I'm wrong and it doesn't cure things then all I've lost is a little time.

Once again, does anyone know 1) why my asl.conf file seems to be already set to not log debug-level error messages but they are being logged, and 2) how I can definitively get these debug-level errors from the kernel to not be logged? Thanks to anyone who can help me with these questions!

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Answer 4

rccharles

Level 6

12,957 points

Apr 4, 2015 2:04 PM in response to reezekeys

I'm mostly unfamiliar with Mac OS X loging.

You could send the log to the bitbucket ( ignore all the loging message via).

# you will need to find the name of the log file.

# I have not tried this with an actual log file.

# There must be a better way of doing this.

rename asl.log file

mv -i asl.log asl-original.log

send data to bye bye land.

ln -s /dev/null asl.log

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Answer 5

reezekeys Author

Level 1

5 points

Apr 5, 2015 8:29 AM in response to rccharles

I really appreciate you trying to help! I'm a little skittish about trying your suggestion after reading words like "mostly unfamiliar", "I have not tried this", and "There must be a better way of doing this." 😀

From what I can gather, your commands would just turn logging off completely? I'm not against this, especially if there was some way to run a batch file with Automator to do this before a gig, then run another one to restore logging when I was done. Thanks again for the help.

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Answer 6

Tony T1

Level 6

10,232 points

Apr 5, 2015 10:40 AM in response to reezekeys

reezekeys wrote:

I'm a musician running a laptop rig (OSX 10.9.5) and am experiencing a fairly rare (once in about 10-15 gigs) and random situation of my audio being interrupted for a few seconds (buzzes or cuts out completely). When I look in Console I see that at the exact time this happens, asl is flooded with over a thousand messages like this:

Which audio software?

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Answer 7

Tony T1

Level 6

10,232 points

Apr 5, 2015 10:45 AM in response to reezekeys

reezekeys wrote:

Your answer is not helpful. My question was regarding logging of debug-level error messages.

It probably won't do much good to engage any further about the original problem I'm dealing with, but here is what an Apple engineer had to say about these clipIfNecessary() messages: "The log message about this is probably unnecessary and should probably be relegated to debug builds." Link:

https://groups.google.com/forum/#!topic/coreaudio-api/GXXUWIYAb_k

Is that date right? 5 years ago?

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Answer 8

reezekeys Author

Level 1

5 points

Apr 5, 2015 1:41 PM in response to Tony T1

Tony T1 wrote:

Which audio software?

I use Plogue Bidule hosting a variety of AU and VST plugins, some of them a few years old, from many differentcompanies. A potpourri of software making this issue pretty much impossible to troubleshoot. I've tried as much as I could – checked all the logs for any kind of message right around the same time stamp as the clipIfNecessary() messages – zip. The log flooding happens at totally random times, not when I'm being especially tough on my audio s/w; I can't reproduce it. And, as I said, while the messages can appear at any point (I check Console immediately after a gig), they don't always cause audio dropouts – it looks like the audio issues only happen when there are thousands of these messages occurring over a short period (a few seconds).

So you can maybe understand why turning off logging is a logical next step in dealing with this! I really do believe it's syslog (or is it syslogd?) flooding the log for those few seconds that's the actual cause of the audio dropouts.

My previous laptop was a 2007 MBP 2.2 Ghz Core 2 Duo running Snow Leopard and it was flawless. I did gigs with that rig for years without a single issue. When I got my new laptop in January of 2014 with 10.9.0 things were OK. Sometime this past fall I upgraded to 10.9.4 and the dropouts started. I can not 100% blame Apple as around that time I upgraded a few plugins and edited my Plogue Bidule setup a bit too – but I've been doing that continuously, even back when I had the older MBP w/10.6.8, and there was never an issue back then. Sorry for the length of this!!

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Answer 9

reezekeys Author

Level 1

5 points

Apr 5, 2015 1:51 PM in response to Tony T1

Tony T1 wrote:

reezekeys wrote:

https://groups.google.com/forum/#!topic/coreaudio-api/GXXUWIYAb_k

Is that date right? 5 years ago?

Yea, this error has been around a while!

Here's a post from someone who experienced that same thing I did, and was told it had to do with Mavericks and that he needed to go back to Mountain Lion! The OP did that and it worked for him. I can't do that – my late 2014 MBP shipped with Mavericks 10.9.0, it's now at 10.9.5 and there is no way for me to even go back to 10.9.0.

http://www.motunation.com/forum/viewtopic.php?f=2&t=57838

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Answer 10

vogelFM

Level 1

0 points

Jul 31, 2015 8:02 PM in response to reezekeys

Hey Reezekeys, I just saw your trail of posts about this as I've been Googling around trying to find a resolution.

I'm running Mavericks on an early 2014 MacBook Pro with an SSD, and I am experiencing these issues with Mainstage, Cubase, and Traktor, and with two different audio interfaces (one MOTU, one Native Instruments.) The exact same issue, the exact randomness, the exact log errors. I have not tried upgrading to Yosemite yet because from everything I'm seeing, the problem happens there as well.

There is no crazy third-party software installed, no weird custom tweaks. In fact, I re-installed the OS hoping to resolve the issue, and it still happens. Again, with two separate audio interfaces, and several different audio apps, one being Apple's own (Mainstage) all running cleanly installed, with no third-party software attached.

I've bookmarked countless threads on the Internet about this issue, with no resolution, so I'm 100% convinced there is an issue happening deep in Core Audio that Apple won't address. My hunch is that something is wrong with the USB hardware and a high number of bad batches made it out into the wild.

So many people are experiencing this with various configurations, and the only single common factor is any operating system higher than Mountain Lion.

I can't perform with my MacBook Pro any longer, due to multiple failures happening during gigs, so I'm seeking alternatives until this is resolved.

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