Milter-greylist

On Wed, Sep 26, 2007 at 10:14:10AM -0000, marknreynolds wrote:
[..]
> 
> I am not a programmer, however I have been logging the number of
> threads milter-greylist is creating and have seen it go up to 290. If
> I run pmap on the process I can see each thread is taking 8M of memory
> so by the time I multiply 8M by 290 and add on the size of the
> greylist database (around 300MB) I am starting to approach 3GB which I
> believe is the limit for user space memory within a process. 
> 
> I am currently waiting for the next errors so I can confirm how many
> threads were open at the time.
> 
> Have I hit a physical limit or is there any tuning I can carry out to
> prevent the problem re-occuring?

I had a similar problem (in some other context). Running a system with
Linux FC5 I saw an overall consumption of at least 10M for each thread,
filling up the virtual memory of the thread container process which is
limited to 3 (or 2?) GB. Some investigation showed that the default
process stacksize is taken for each(!) new thread ... Now I have limited
the stack size in the init script using

ulimit -s 256

to 256 KB which worked for me (e.g. Solaris is not that wastful in
stack usage for threads).


Johann