Performance issues with our internal memory allocator

Hey,

so we have been running our in-build performance tests now for a few weeks
and recently discovered that our internal memory allocator is causing
spikes in the runtime. It became even worse during the weekend with the
tests taking 200 times the instructions. Most of it seems to be spend in
our memory handling code and not really in the actual code. (see for
example
http://perf.libreoffice.org/perf_html/ftest_of_cppu_sc_on_vm139.details.html
with the annotated callgrind ouput at http://pastebin.com/ELC64s1n).
We had a profile that showed the issue inside of the memory allocator much
better but I have to find it again.

Is the internal memory allocator really still useful despite showing
sometimes really bad behavior? Personally I would just fall back to the
system memory allocator except for the few cases where we know that it
makes a difference (small memory blocks in calc formula tokens, ...)

Regards,
Markus