With a plain standard configuration I can confirm behavior of wrk on Ubuntu 16.04 (Linux 4.4.0):
Running without reload during run:
$ wrk -d 30 -c 100 -t 20 http://localhsot/
Running 30s test @ http://localhost/
20 threads and 100 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 2.45ms 0.89ms 29.75ms 86.77%
Req/Sec 2.07k 279.09 5.32k 78.41%
1241732 requests in 30.10s, 1.45GB read
Requests/sec: 41248.07
Transfer/sec: 49.25MB
Calling reload one time during run:
$ wrk -d 30 -c 100 -t 20 http://localhost/
Running 30s test @ http://localhost/
20 threads and 100 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 5.34ms 8.76ms 91.81ms 85.10%
Req/Sec 1.22k 0.86k 5.43k 58.83%
688865 requests in 30.10s, 822.49MB read
Socket errors: connect 0, read 39, write 0, timeout 0
Requests/sec: 22887.01
Transfer/sec: 27.33MB
Could not verify a connection termination with a reload during a long running request. Might be a "problem" with wrk?