It seems to be spending a lot of time in create_delta. I have added a breakpoint on calling create_delta and a few good minutes pass between the breakpoint being hit. The large loop in create_delta has practically no outgoing function calls (save for the realloc on line 476), so I still don't understand how dstat could report 0% user time. htop indicates the worker threads are using 100% CPU time.
florin
