Threaded 6.4 code compiled under 9.0 uses a lot more memory?..

[Jan Mikkelsen]

Hi,


On 30/10/2012, at 10:12 PM, Karl Pielorz <kpielorz_lst at tdx.co.uk> wrote:

> 
> Hi All,
> 
> Can anyone think of any quick pointers as to why some code originally written under 6.4 amd64 - when re-compiled under 9.0-stable amd64 takes up a *lot* more memory when running?
> 
> The code involved is a sendmail Milter, and a TCP server type program (that runs up a large number of threads [~700] at startup).
> 
> Both were previously compiled with:
> 
> -O2 -pthread -lc_r
> 
> They're now compiled under 9.0-S with just:
> 
> -O2 -pthread

libc_r is a user mode implementation of pthreads, so there is one actual kernel thread with a stack. You now have ~700 kernel threads on startup. Per-thread stack allocation will be different, and you could quite easily explain differences that way.

Regards,

Jan.