copy from https://lists.fd.io/g/vpp-dev/topic/103039486

internal_mallinfo in dlmalloc.c has complexity of O(memory chunks count), because it calculates stats by doing linked list iteration over all allocated objects. And in our case (vpp-upf plugin) we have millions of allocated objects.
 
In our load test mspace_mallinfo hangs upg-vpp every 10 seconds for ~0.18 seconds
with 4.5 millions of allocated objects/ This makes is so vpp stopped for 1.8% of the time and results in >1% packetloss even when vpp is not fully loaded.
With workaround (removed stats collection) packetloss is 0.

Screenshot of hotspot performance tool with blue parts being mspace_mallinfo

Most probably this issue affects more deployments, but not as noticeable.