Re: Memory leaks in Kernel 2.6.32.28

On Fri, Feb 11, 2011 at 09:04:25AM +0100, karesmakro wrote:
> Hello there,
> I know, the copfilter project is not appreciated very well! But this 
> problem do not belong only to copfilter, it's a common problem. I 
> noticed on applications, which uses much of memory (e.g. clamav), that 
> the memory is growing from day to day. I also noticed, if the 
> applications are restarted, the memory is not freeing (only a small part)
> So my Cop was running 3 weeks and I had 56MB swapped space (with 1GB 
> RAM) and was growing.


56MB swap is not unusual. Things are not being used (eg spare login
consoles) are swapped out to make way for more cache:
	http://en.wikipedia.org/wiki/Memory_leak#Other_memory_consumers

Look at the output of 'free -t', 'top', 'less /proc/cpuinfo' and
'less /proc/vmallocinfo to get more information about memory use.

Emails about a "memory leak" in IPCop have occured in the past and it
usually turns out to be kernel cache or a service using more memory.
Have a search of "memory leak" in the IPCop mailing lists archives:
	http://marc.info/?l=ipcop-user
	http://marc.info/?l=ipcop-devel


> I made some tests and also compiled clamav only with needed functions, 
> but this seems not to solve the problem. After some researches, I found 
> a well known kernel bug in mm page-allocator
> https://answers.launchpad.net/ubuntu/+source/linux/+question/130117

That question is for the kernel using the oom-killer (Out-Of-Memory
Killer) to stop processes when it is out of memory. Have you seen
that behaviour (eg services or programs stopping suddenly)? Search
/var/log/messages for "oom".

Also that question is for 2.6.32.25, and IPCop uses 2.6.32.28:
	http://sourceforge.net/apps/trac/ipcop/browser/ipcop/trunk/lfs/linux

The bug report referenced is for an even older version of the kernel
(2.6.32.23) and fixed in 2.6.32.26:
	https://bugs.launchpad.net/ubuntu/+source/linux/+bug/649483

And the original poster found the problem was vftpd (an FTP server)
and not the kernel.

I have many Ubuntu and Debian servers running 2.6.32 and have not had
any problems with memory usage on them. And some of run vsftpd. So I
am not sure how "well known" this really is.


> I'm currently using SVN Build 5349 and as I remember right, this was no 
> problem in SVN Builds at around Sep. - Nov. 2010
> 
> 
> So I hope, someone can say anything about!
> 
> regards, karesmakro



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