Preferably, use MALLOC_OPTIONS="AJ" and/or other facilities.
Benchmark:
npftest -b rule -c /tmp/npf.nvlist -p $ncpu
---
Update RUMP libraries once the kernel side has been changed. Hint:
cd src/sys/net/npf
sudo make includes
cd src/sys/rump/net/lib/libnpf
make distclean
MKDEBUG=yes MKDEBUGLIB=yes DBG="-g -O2" make -j8
sudo MKDEBUG=yes MKDEBUGLIB=yes DBG="-g -O2" make install