[AG-TECH] RAT Memory leak (ubuntu 10.10)

Christoph Willing c.willing at uq.edu.au
Sun Nov 28 00:17:17 CST 2010

I can confirm this problem. It appears to involve a small memory leak  
in rat itself when using an ALSA device whenever Talk is enabled. This  
becomes a major memory leak when Pulse audio is involved - a 0.1%  
increase every few seconds in the rat-*-media process, as well as a  
jump in cpu usage from 1 or 2% to 36%.

It was previously e.g. Ubuntu 10.4, possible to use OSS instead of  
ALSA (and therefore have no memory problem) but OSS is no longer  
available in Ubuntu 10.10.

Here's a summary of test results using code form the svn trunk (r4891)

On a system with no Pulse Audio, both OSS and ALSA available:
   OSS  selected - uses total 1% cpu, 0.3% mem., irrespective of Talk  
being on or off
   ALSA selected - uses total 1% cpu, 0.3% mem., adds about 0.1% every  

On a system with Pulse Audio & ALSA, but no OSS (Ubuntu 10.10)
   Talk off - uses total 2% cpu, 0.2% mem usage at start, 0.8% after  
   Talk on  - uses total 36% cpu, 0.2% mem usage at start, increasing  
by 0.1% every 3 seconds
                                  i.e. 30% mem usage after 10 minutes  
on the test machine.

I see from the rat svn repo that there's been no change in the source  
code for a long time, so the problem must have been around for a long  
time; maybe it hasn't been noticed because most users have previously  
chosen to run rat with OSS rather than ALSA+Pulse, or perhaps the  
current version of Pulse particularly exercises the faulty code. Also,  
on the test machine at least, it requires using rat with Talk on for  
about 30 minutes before the problem would be noticed (unless you just  
happen to be carefully watching top at the same time).


On 25/11/2010, at 8:11 PM, Philippe d'Anfray wrote:

> Bonjour,
> We used our ubuntu 10.10 server to retransmit a seminar last week.
> But RAT was "eating" all the available memory and eventually crashed
> every 10-15 minutes.
> syslog:Nov 18 17:02:32 aristotest1 kernel: [31358.739815] Out of  
> memory: kill process 3720 (rat-4.4.01) score 1977288 or a child
> syslog:Nov 18 17:02:32 aristotest1 kernel: [31358.739820] Killed  
> process 3721 (rat-4.4.01-ui) vsz:44748kB, anon-rss:2044kB, file-rss: 
> 12kB
> syslog:Nov 18 17:02:32 aristotest1 kernel: [31358.800101] rat-4.4.01- 
> ui: page allocation failure. order:0, mode:0x201da
> syslog:Nov 18 17:02:32 aristotest1 kernel: [31358.800106] Pid: 3721,  
> comm: rat-4.4.01-ui Not tainted 2.6.35-22-generic #34-Ubuntu
> Has anyone else experienced a similar problem?
> Cordialement
> Philippe
> <rat.jpg><Philippe_d-Anfray.vcf>

Christoph Willing                       +61 7 3365 8316
QCIF Access Grid Manager
University of Queensland

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